Table of SynGAP1 Isoform α2 (UniProt Q96PV0-1) Missense Variants.

c.dna	Variant	SGM Consensus	Domain	ClinVar			gnomAD			ESM1b		AlphaMissense			REVEL		FoldX			Rosetta		Foldetta		PremPS		PROVEAN		PolyPhen-2 HumDiv		PolyPhen-2 HumVar		FATHMM		SIFT				PAM		Physical		SASA		Normalized B-factor backbone		Normalized B-factor sidechain		SynGAP Structural Annotation									DOI
				Clinical Status	Review	Subm.	ID	Allele count	Allele freq.	LLR score	Prediction	Pathogenicity	Class	Optimized	Score	Prediction	Average ΔΔG	Prediction	StdDev	ΔΔG	Prediction	ΔΔG	Prediction	ΔΔG	Prediction	Score	Prediction	pph2_prob	Prediction	pph2_prob	Prediction	Nervous System Score	Prediction	Prediction	Status	Conservation	Sequences	PAM250	PAM120	Hydropathy Δ	MW Δ	Average	Δ	Δ	StdDev	Δ	StdDev	Secondary	Tertiary bonds	Inside out	GAP-Ras interface	At membrane	No effect	MD Alert	Verdict	Description
c.1312G>A	A438T (3D Viewer)	Likely Benign	GAP	Conflicting		3	6-33438217-G-A	16	9.91e-6	-5.339	Likely Benign	0.085	Likely Benign	Likely Benign	0.021	Likely Benign	0.21	Likely Benign	0.0	-0.07	Likely Benign	0.07	Likely Benign	0.36	Likely Benign	-0.81	Neutral	0.300	Benign	0.011	Benign	4.18	Benign	0.14	Tolerated	3.38	26	1	0	-2.5	30.03	214.2	-42.7	-0.3	0.1	-0.4	0.1						X					Potentially Benign	The methyl group of Ala438, located in a four-residue loop connecting two α helices (res. Asn440-Thr458 and Pro413-Glu436), packs against hydrophobic residues from a nearby α helix or loop residues (e.g., Leu703, Val699). In the variant simulations, the methyl group of Thr438 is able to establish similar hydrophobic packing. Moreover, the hydroxyl group also H-bonds with nearby residues, such as the carbonyl group of the neighboring loop residue Pro437. Accordingly, the residue swap does not generate an apparent negative effect on the protein structure based on the simulations.
c.694G>A	A232T (3D Viewer)		PH	Benign		1	6-33435545-G-A	1	6.20e-7	-7.655	In-Between	0.874	Likely Pathogenic	Ambiguous	0.469	Likely Benign	0.47	Likely Benign	0.1	-0.04	Likely Benign	0.22	Likely Benign	0.61	Ambiguous	-1.42	Neutral	0.608	Possibly Damaging	0.240	Benign	5.80	Benign	0.09	Tolerated	3.40	14	1	0	-2.5	30.03	210.8	-42.0	0.5	0.1	0.4	0.5						X		Uncertain	The hydroxyl group of Thr232, located at the end of an anti-parallel β sheet strand (res. Thr228-Ala232), forms hydrogen bonds with nearby residues Glu217, Cys233, and Cys219 in the variant simulations. These hydrogen-bonding interactions at the β sheet surface contribute to the stability of the secondary structure element and prevent it from unfolding. The new hydrogen bond interactions may be more favorable for structural stability than the steric interactions of the methyl side chain of Ala with the side chains of Gln216 and Cys219 in the WT. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1195G>A	A399T (3D Viewer)	Likely Benign	C2	Benign		1				-5.236	Likely Benign	0.114	Likely Benign	Likely Benign	0.272	Likely Benign	1.24	Ambiguous	0.1	0.91	Ambiguous	1.08	Ambiguous	0.49	Likely Benign	-0.40	Neutral	0.131	Benign	0.039	Benign	5.41	Benign	0.69	Tolerated	3.38	26	1	0	-2.5	30.03	211.4	-41.4	0.0	0.0	0.6	0.4		X						Potentially Pathogenic	The methyl group of Ala399, located in an anti-parallel β sheet strand (res. Ala399-Ile411), is swapped for a hydroxyl-containing threonine. In the variant simulations, the hydroxyl group of Thr399 can form H-bonds with the backbone atoms of the residues in the membrane-facing loops (e.g., Gly382) in the C2 domain. Consequently, the ability of the Thr399 side chain to form H-bonds with the membrane-facing loops could adversely affect the dynamics and stability of the SynGAP-membrane association. However, since the effects on the dynamics of the membrane-facing loops can only be studied through the SynGAP-membrane complex, no definite conclusions can be drawn.
c.2089T>C	W697R (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33441348-T-C	1	6.20e-7	-10.020	Likely Pathogenic	0.941	Likely Pathogenic	Ambiguous	0.401	Likely Benign	1.14	Ambiguous	0.1	1.18	Ambiguous	1.16	Ambiguous	1.25	Destabilizing	-9.50	Deleterious	1.000	Probably Damaging	0.994	Probably Damaging	3.45	Benign	0.02	Affected	3.46	13	2	-3	-3.6	-30.03	254.4	-41.2	0.0	0.0	-0.7	0.0						X		Potentially Benign	The indole ring of Trp697, located on the outer surface of an α-helix (res. Leu685-Val699), is not involved in any long-lasting interactions in the WT simulations. In the variant simulations, the positively charged guanidinium side chain of Arg697 occasionally forms hydrogen bonds with nearby residues, such as Ser722 and Asn719. However, similar to Trp697 in the WT, Arg697 does not form any long-lasting interactions and thus does not induce any negative structural effects in the simulations.
c.1199T>A	V400E (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-13.686	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.810	Likely Pathogenic	3.70	Destabilizing	0.2	2.46	Destabilizing	3.08	Destabilizing	2.29	Destabilizing	-4.88	Deleterious	0.920	Possibly Damaging	0.335	Benign	5.31	Benign	0.00	Affected	3.38	27	-2	-2	-7.7	29.98	249.1	-38.8	-0.1	0.1	1.0	0.0	X		X				X	Potentially Pathogenic	The iso-propyl side chain of Val400, located in an anti-parallel β sheet strand (res. Ala399-Ile411), hydrophobically packs against hydrophobic residues within the anti-parallel β sheet of the C2 domain (e.g., Ile268, Ala404, Leu325, Leu402). In the variant simulations, the negatively charged carboxylate group of the Glu400 side chain is not suitable for occupying the hydrophobic niche. Consequently, the side chain escapes the center of the C2 domain and interacts with the backbone amide groups of Leu402 in the same β strand and/or Ile269 and Glu270 in a neighboring β strand (res. Arg259-Arg272). This residue swap disrupts the hydrophobic packing and generally has extensive negative effects on the C2 domain structure. At a minimum, the residue swap could affect the C2 domain stability and membrane association.
c.1714T>C	W572R (3D Viewer)	Likely Pathogenic	GAP	Not provided		1				-17.511	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.894	Likely Pathogenic	4.84	Destabilizing	0.1	6.19	Destabilizing	5.52	Destabilizing	1.79	Destabilizing	-12.81	Deleterious					-1.25	Pathogenic	0.00	Affected	3.37	35	2	-3	-3.6	-30.03	312.6	-37.6	0.0	0.0	-1.0	0.0		X	X					Potentially Pathogenic	The indole ring of Trp572, located in an α-helix (res. Arg563-Glu578), lies in a hydrophobic inter-helix space, where it makes extensive hydrophobic interactions with nearby residues such as Met470, Phe569, Leu588, and Ile589. The guanidinium group of Arg572 is similarly sized to the tryptophan it replaced; however, it is also positively charged. In the variant simulations, Arg572 forms hydrogen bonds with other residues in the inter-helix space, such as Ser592 and the backbone carbonyl atom of Leu465. Additionally, Arg572 hydrophobically packs its carbon chain with surrounding residues such as Phe569 and Ile589.However, the introduced residue arginine is too hydrophilic and charged for the hydrophobic space, disrupting the hydrophobic packing of the inter-helix space. Indeed, in the second simulation, Arg572 successfully escapes the hydrophobic niche completely, causing the whole protein to partially unfold.Overall, the residue swap is highly likely to cause critical protein folding problems, as evidenced by the effects seen in the variant simulations.
c.1354G>T	V452F (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.769	Likely Pathogenic	0.975	Likely Pathogenic	Likely Pathogenic	0.511	Likely Pathogenic	9.21	Destabilizing	0.1	0.37	Likely Benign	4.79	Destabilizing	0.61	Ambiguous	-4.94	Deleterious	0.999	Probably Damaging	0.993	Probably Damaging	3.29	Benign	0.00	Affected	3.37	34	-1	-1	-1.4	48.04	249.4	-35.7	0.0	0.0	0.4	0.1							X	Potentially Pathogenic	The iso-propyl side chain of Val452, located in the middle of an α helix (res. Val441-Ser457), packs against hydrophobic residues in the inter-helix space at the intersection of three α helices (e.g., Leu500, His453, Leu465). In the variant simulations, the larger side chain of Phe452 cannot pack against the opposing α helix (res. Leu489-Glu519) as efficiently as valine. Due to space restrictions, the phenol ring adjusts to make room by rotating slightly sideways in the inter-helix space. Besides this small and local shift, no large-scale effects on the protein structure are seen based on the simulations. However, the size difference between the swapped residues could affect the protein folding process.
c.1084T>C	W362R (3D Viewer)	Likely Pathogenic	C2	Pathogenic		2				-14.004	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.706	Likely Pathogenic	2.64	Destabilizing	0.3	3.90	Destabilizing	3.27	Destabilizing	1.10	Destabilizing	-12.87	Deleterious	0.999	Probably Damaging	0.996	Probably Damaging	1.28	Pathogenic	0.00	Affected	3.39	24	2	-3	-3.6	-30.03	287.5	-34.1	-0.2	0.1	-0.6	0.2	X			X			X	Potentially Pathogenic	The indole ring of Trp362, located on the surface of an anti-parallel β sheet (res. Thr359-Pro364) in the C2 domain, stacks with nearby residues (e.g., Arg401, Arg272). In the variant simulations, the guanidinium group of the introduced residue Arg362 forms a salt bridge with the carboxylate group of Glu273 and, like Trp362, stacks with other arginine residues (e.g., Arg401, Arg272). This residue is at both the C2-membrane interface and the C2-RasGTPase interface, so the residue swap could potentially affect both interactions. However, these phenomena cannot be addressed using solvent-only simulations. Notably, Arg272, which stacks with both the non-mutated Trp362 and the mutated Arg362, forms a salt bridge directly with Asp105 of Ras in the WT simulations. Therefore, the residue swap could affect the C2 domain stability, the SynGAP-membrane association, and the SynGAP-Ras association.	10.1016/j.ajhg.2020.11.011
c.2168C>T	T723I (3D Viewer)	Likely Benign	GAP	Likely Benign		1	6-33441633-C-T	2	1.24e-6	-2.591	Likely Benign	0.120	Likely Benign	Likely Benign	0.045	Likely Benign	-0.39	Likely Benign	0.0	-0.20	Likely Benign	-0.30	Likely Benign	0.26	Likely Benign	-2.09	Neutral	0.088	Benign	0.030	Benign	3.39	Benign	0.03	Affected	3.50	8	0	-1	5.2	12.05	252.3	-31.6	0.0	0.0	-0.2	0.2						X		Uncertain	The hydroxyl group of Thr723, located on the outer surface of an α-helix (res. Leu714-Arg726), continuously forms hydrogen bonds with the backbone carbonyl of Asn719 in the WT simulations, potentially lowering the stability of the α-helix. In the variant simulations, the sec-butyl side chain of Ile723 cannot form any hydrogen bonds, which, in theory, could increase the helix stability. However, because the model ends abruptly at the C-terminus, no definite conclusions can be drawn based on the simulations.
c.1198G>C	V400L (3D Viewer)	Likely Benign	C2	Benign		1	6-33438103-G-C	22	1.36e-5	-1.000	Likely Benign	0.137	Likely Benign	Likely Benign	0.325	Likely Benign	-0.71	Ambiguous	0.2	0.39	Likely Benign	-0.16	Likely Benign	-0.29	Likely Benign	-0.60	Neutral	0.001	Benign	0.001	Benign	5.33	Benign	0.64	Tolerated	3.38	27	2	1	-0.4	14.03	251.0	-30.1	0.0	0.0	0.7	0.1						X		Potentially Benign	The iso-propyl side chain of Val400, located in an anti-parallel β sheet strand (res. Ala399-Ile411), hydrophobically packs against hydrophobic residues within the anti-parallel β sheet of the C2 domain (e.g., Ile268, Ala404, Leu325, Leu402). Val400 is swapped for another hydrophobic residue, leucine, whose branched hydrocarbon side chain is of a comparable size and thus packs favorably within the C2 domain. In short, the residue swap has no apparent negative effect on the structure based on the variant simulations.	10.1016/j.ajhg.2020.11.011
c.2111G>A	S704N (3D Viewer)	Likely Benign	GAP	Benign/Likely benign		3	6-33441370-G-A	27	1.67e-5	-5.917	Likely Benign	0.421	Ambiguous	Likely Benign	0.058	Likely Benign	0.48	Likely Benign	0.1	-0.12	Likely Benign	0.18	Likely Benign	0.54	Ambiguous	-0.49	Neutral	0.771	Possibly Damaging	0.275	Benign	3.39	Benign	0.08	Tolerated	3.47	10	1	1	-2.7	27.03	233.2	-29.1	-0.1	0.0	-0.1	0.1						X		Potentially Benign	Ser704 is located at the end and outer surface of an α-helix (res. Thr704-Gly712), which is connected via a tight turn or loop to another α-helix (res. Asp684-Gln702). The hydroxyl side chain of Ser704 occasionally forms a hydrogen bond with the amide group of Ala707. However, in the variant simulations, the carboxamide side chain of Asn704 achieves more lasting and numerous hydrogen-bonding interactions with the residues at the helix end, such as Glu706, Ala707, and Leu708. Consequently, the residue swap could strengthen the α-helix secondary structure integrity at the helix end, which could have either positive or negative effects on its function.
c.1300G>A	V434I (3D Viewer)	Likely Benign	GAP	Uncertain		1	6-33438205-G-A	1	6.19e-7	-6.999	Likely Benign	0.129	Likely Benign	Likely Benign	0.192	Likely Benign	-0.04	Likely Benign	0.0	0.22	Likely Benign	0.09	Likely Benign	0.31	Likely Benign	-0.82	Neutral	0.947	Possibly Damaging	0.851	Possibly Damaging	3.53	Benign	0.18	Tolerated	3.37	29	4	3	0.3	14.03	246.7	-27.7	0.0	0.0	0.1	0.0						X		Potentially Benign	The iso-propyl side chain of Val434, located at the end of an α helix (res. Met414-Glu436), packs against hydrophobic residues in an interhelix space (e.g., Met430, Ala707, Leu711). In the variant simulations, the sec-butyl group of Ile434 is able to form the same hydrophobic interactions. Accordingly, the residue swap does not negatively affect the protein structure based on the simulations.
c.1027G>A	V343I (3D Viewer)	Likely Benign	C2	Uncertain		2	6-33437932-G-A	1	6.20e-7	-6.020	Likely Benign	0.117	Likely Benign	Likely Benign	0.020	Likely Benign	-0.27	Likely Benign	0.0	-0.04	Likely Benign	-0.16	Likely Benign	-0.39	Likely Benign	-0.14	Neutral	0.159	Benign	0.084	Benign	1.98	Pathogenic	0.27	Tolerated	3.37	25	4	3	0.3	14.03	240.2	-26.9	-0.2	0.2	-0.2	0.2						X		Potentially Benign	The iso-propyl side chain of Val343, located in an anti-parallel β sheet strand (res. Gly341-Pro349), is packing against multiple hydrophobic residues of the C2 domain (e.g., Leu327, Leu274, Val365). In the variant simulations, the sec-butyl side chain of Ile343 is basically able to form the same interactions as valine due to its similar hydrophobic profile. The residue swap also does not seem to cause negative effects on the protein structure based on the simulations.
c.922T>C	W308R (3D Viewer)	Likely Pathogenic	C2	Pathogenic		1				-12.264	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.868	Likely Pathogenic	5.40	Destabilizing	0.5	4.27	Destabilizing	4.84	Destabilizing	1.88	Destabilizing	-12.87	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	0.48	Pathogenic	0.00	Affected	3.38	19	2	-3	-3.6	-30.03	290.4	-26.7	-0.1	0.1	0.0	0.2	X		X				X	Potentially Pathogenic	The indole ring of Trp308, located in an anti-parallel β sheet strand (res. Thr305-Asn315), packs against multiple hydrophobic residues (e.g., Ile268, Val306, Cys282). The indole group of Trp308 also hydrogen bonds with the backbone atoms of the C2 domain residues forming the anti-parallel β sheet (e.g., Tyr280, Thr294). The guanidinium group of Arg308 is comparably sized to the tryptophan it replaced; however, it is also positively charged.In the variant simulations, the charged side chain remains buried deep in the hydrophobic part of the C2 domain, where it forms new hydrogen bonds with the backbone carbonyl atoms of surrounding residues (e.g., Val306, Ile268). However, the residue swap is likely to disrupt the hydrophobic packing during folding. At a minimum, the residue swap could affect the C2 domain stability and membrane association.
c.1304T>G	L435W (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.889	Likely Pathogenic	0.992	Likely Pathogenic	Likely Pathogenic	0.572	Likely Pathogenic	2.11	Destabilizing	0.1	0.69	Ambiguous	1.40	Ambiguous	1.66	Destabilizing	-5.63	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	3.15	Benign	0.00	Affected	3.37	29	-2	-2	-4.7	73.05	242.2	-25.2	0.0	0.0	0.3	0.1							X	Potentially Pathogenic	The iso-butyl side chain of Leu435, located in an α helix (res. Met414-Glu436), packs against other hydrophobic residues in an interhelix space (e.g., Val699, Val447, Leu489, Leu439) in the WT simulations. In the variant simulations, the indole ring of Trp435 fits into the same niche despite its considerably bulkier size. Additionally, the side chain forms an H-bond with the backbone carbonyl of Leu696 in an α helix (res. Asp684-Gln702). Although no apparent negative changes are observed during the variant simulation, the size difference between the swapped residues could affect the protein folding process.
c.603T>A	D201E (3D Viewer)	Likely Benign	PH	Benign		1				-2.640	Likely Benign	0.406	Ambiguous	Likely Benign	0.165	Likely Benign	0.42	Likely Benign	0.2	1.99	Ambiguous	1.21	Ambiguous	0.23	Likely Benign	-0.69	Neutral	0.633	Possibly Damaging	0.108	Benign	4.30	Benign	1.00	Tolerated	3.46	9	3	2	0.0	14.03	258.7	-24.8	0.9	0.1	-0.3	0.2						X		Uncertain	Asp201, an acidic residue located in the N-terminal loop before the first anti-parallel β sheet strand (res. Ile205-Pro208), is replaced by another acidic residue, glutamate. The carboxylate groups of both Asp201 and Glu201 side chains form hydrogen bonds with the hydroxyl group of Ser221 in the simulations. Due to its shorter side chain, Asp201 can also hydrogen bond with the backbone amide groups of neighboring loop residues Ser204 and Asp203. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.603T>G	D201E (3D Viewer)	Likely Benign	PH	Conflicting		2	6-33435245-T-G	20	1.24e-5	-2.640	Likely Benign	0.406	Ambiguous	Likely Benign	0.165	Likely Benign	0.42	Likely Benign	0.2	1.99	Ambiguous	1.21	Ambiguous	0.23	Likely Benign	-0.69	Neutral	0.633	Possibly Damaging	0.108	Benign	4.30	Benign	1.00	Tolerated	3.46	9	3	2	0.0	14.03	258.7	-24.8	0.9	0.1	-0.3	0.2						X		Uncertain	Asp201, an acidic residue located in the N-terminal loop before the first anti-parallel β sheet strand (res. Ile205-Pro208), is replaced by another acidic residue, glutamate. The carboxylate groups of both Asp201 and Glu201 side chains form hydrogen bonds with the hydroxyl group of Ser221 in the simulations. Due to its shorter side chain, Asp201 can also hydrogen bond with the backbone amide groups of neighboring loop residues Ser204 and Asp203. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1767C>G	I589M (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-12.225	Likely Pathogenic	0.926	Likely Pathogenic	Ambiguous	0.830	Likely Pathogenic	0.74	Ambiguous	0.2	1.54	Ambiguous	1.14	Ambiguous	1.33	Destabilizing	-2.99	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.94	Pathogenic	0.00	Affected	3.37	35	2	1	-2.6	18.03	267.6	-24.5	0.0	0.0	-0.1	0.1						X		Potentially Benign	A hydrophobic residue, Ile589, located in an α helix (res. Glu582-Met603), is swapped for another hydrophobic residue, methionine. The sec-butyl hydrocarbon side chain of Ile589 packs favourably with multiple residues in the inter-helix hydrophobic space (e.g., Phe569, Ile667, and Leu664).Although the S-methyl thioether group of the Met589 side chain in the variant is longer than the branched side chain of isoleucine, it stacks favourably with the aromatic phenol ring. Additionally, the polar sulphur atom forms a weak hydrogen bond with the guanidinium group of Arg573, which in turn forms a salt bridge with the carboxylate group of Asp586.Overall, the hydrophobic packing in the inter-helix space does not appear to be disrupted in the variant simulations.
c.762G>C	K254N (3D Viewer)	Likely Pathogenic	PH	Uncertain		1				-13.306	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.757	Likely Pathogenic	0.73	Ambiguous	0.2	1.87	Ambiguous	1.30	Ambiguous	1.19	Destabilizing	-4.23	Deleterious	0.384	Benign	0.070	Benign	5.93	Benign	0.01	Affected	3.39	15	1	0	0.4	-14.07	215.3	-21.0	-1.0	1.7	0.2	0.3		X						Potentially Pathogenic	The amino group of Lys254, located in an α-β loop connecting the PH and C2 domains (res. Lys251-Arg258), forms salt bridges with the carboxylate groups of Glu244 and Asp684. Since the neutral carboxamide group of the Asn254 side chain cannot form salt bridges with acidic residues, the residue swap potentially weakens the tertiary structure assembly and/or influences the loop positioning. Regardless, in both the variant and WT simulations, all hydrogen bonds formed by the residue’s side chain were broken, and the residue rotated outwards. The partially α helical conformation of the loop, which extends to a nearby α helix (res. Met414-Asn426), is dynamic, making it unclear if the mutation affects it.
c.1752C>G	I584M (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33440804-C-G	1	6.20e-7	-10.119	Likely Pathogenic	0.419	Ambiguous	Likely Benign	0.478	Likely Benign	0.11	Likely Benign	0.1	0.46	Likely Benign	0.29	Likely Benign	1.16	Destabilizing	-2.62	Deleterious	0.983	Probably Damaging	0.925	Probably Damaging	-1.25	Pathogenic	0.12	Tolerated	3.37	34	2	1	-2.6	18.03	247.5	-20.3	-0.1	0.3	-0.1	0.1						X		Potentially Benign	A hydrophobic residue, Ile584, located in an α helix (res. Glu582-Met603), is swapped for another hydrophobic residue, Met584. The sec-butyl hydrocarbon side chain of Ile584 packs hydrophobically with residues in an inter-helix hydrophobic space (e.g., Leu588, Met477, Val473, and Ile483).In the variant simulations, the thioether hydrophobic side chain of Met584 maintains similar interactions as Ile584 in the WT, as it is roughly the same size and fits well within the hydrophobic space. Thus, the residue swap does not appear to cause any negative effects on the protein structure.
c.2115G>C	K705N (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-9.767	Likely Pathogenic	0.925	Likely Pathogenic	Ambiguous	0.183	Likely Benign	0.74	Ambiguous	0.0	0.37	Likely Benign	0.56	Ambiguous	0.44	Likely Benign	-3.12	Deleterious	0.996	Probably Damaging	0.876	Possibly Damaging	3.37	Benign	0.02	Affected	3.47	10	1	0	0.4	-14.07	221.4	-20.2	0.0	0.0	0.0	0.1						X		Uncertain	The amino side chain of Lys705, located at the end and outer surface of an α-helix (res. Thr704-Gly712), does not form any interactions in the WT simulations. In the variant simulations, the carboxamide side chain of Asn705 briefly forms a salt bridge with Glu706. However, there is no apparent difference between the systems. Due to the model ending abruptly at the C-terminus, no definite conclusions can be drawn based on the simulations.
c.1651C>A	L551M (3D Viewer)		GAP	Uncertain		1	6-33438894-C-A	7	4.34e-6	-9.937	Likely Pathogenic	0.480	Ambiguous	Likely Benign	0.544	Likely Pathogenic	-0.07	Likely Benign	0.1	0.13	Likely Benign	0.03	Likely Benign	0.71	Ambiguous	-0.56	Neutral	1.000	Probably Damaging	1.000	Probably Damaging	-1.48	Pathogenic	0.06	Tolerated	3.37	35	4	2	-1.9	18.03	246.5	-18.6	0.0	0.0	0.3	0.0						X		Potentially Benign	L551 is located on an α-helix (res. Ala533-Val560). The iso-butyl side chain of Leu551 hydrophobically packs with nearby hydrophobic residues such as Cys547, Phe652, Leu633, and Ile630 in the inter-helix space. In the variant simulations, the thioether side chain of Met551 can maintain similar hydrophobic interactions as Leu551 in the WT, thus causing no negative effect on the protein structure during the simulations.
c.917T>A	V306D (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-18.289	Likely Pathogenic	0.986	Likely Pathogenic	Likely Pathogenic	0.530	Likely Pathogenic	4.40	Destabilizing	0.3	4.29	Destabilizing	4.35	Destabilizing	2.44	Destabilizing	-5.44	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.74	Pathogenic	0.00	Affected	3.38	19	-2	-3	-7.7	15.96	212.3	-18.3	-0.2	0.4	0.0	0.2	X		X				X	Potentially Pathogenic	The isopropyl group of Val396, located at the beginning of an anti-parallel β sheet strand (res. Thr305-Asn315), packs against multiple hydrophobic residues (e.g., Leu274, Trp308, Ala271) in the WT simulations. However, in the variant simulations, the negatively charged carboxylate group of the Asp306 side chain is not suitable for this hydrophobic niche. Consequently, the side chain moves out to interact with Ser300 in the β strand (res. Met289-Arg299) and the guanidinium group of Arg299 in the β hairpin loop.In the third simulation, the residue swap disrupts the C2 domain secondary structure and tertiary assembly to a large degree when the amino group of the Lys297 side chain rotates to form a salt bridge with Asp306. This drastic effect could potentially reflect the challenge presented by the residue swap during the C2 domain folding. Because the residue swap affects the C2 domain structure, the SynGAP-membrane association could also be impacted. However, this is beyond the scope of the solvent-only simulations to unravel.
c.1045C>T	P349S (3D Viewer)		C2	Uncertain		1				-7.654	In-Between	0.217	Likely Benign	Likely Benign	0.277	Likely Benign	1.92	Ambiguous	0.1	2.28	Destabilizing	2.10	Destabilizing	0.87	Ambiguous	-6.13	Deleterious	1.000	Probably Damaging	0.996	Probably Damaging	1.66	Pathogenic	0.06	Tolerated	3.37	25	1	-1	0.8	-10.04	194.9	-18.1	-0.1	0.0	0.2	0.1	X						X	Potentially Pathogenic	The cyclic pyrrolidine side chain of Pro349, located at the end of an anti-parallel β sheet strand (res. Gly341-Pro349), allows the strand to end and make a tight turn before a short α helical section within a loop connecting to another β strand (res. Thr359-Pro364). In the variant simulations, the hydroxyl group of Ser349 forms a hydrogen bond with the backbone amide group of Ala351 in the short helical section. Conversely, the backbone amide group of Ser349 (absent in proline) does not form any intra-protein hydrogen bonds. However, the β strand end connects to the α helical section in a more stable and consistent manner compared to the WT. Although the residue swap does not cause major adverse effects on the protein structure in the simulations, it is possible that the tight turn at the β strand end could not be created during folding without the presence of proline.
c.2111G>C	S704T (3D Viewer)	Likely Benign	GAP	Uncertain		1				-4.930	Likely Benign	0.265	Likely Benign	Likely Benign	0.071	Likely Benign	0.80	Ambiguous	0.0	0.15	Likely Benign	0.48	Likely Benign	0.29	Likely Benign	-1.72	Neutral	0.525	Possibly Damaging	0.107	Benign	3.45	Benign	0.07	Tolerated	3.47	10	1	1	0.1	14.03	201.7	-18.0	0.0	0.0	-0.2	0.7						X		Potentially Benign	Ser704 is located at the end and outer surface of an α-helix (res. Thr704-Gly712), which is connected via a tight turn or loop to another α-helix (res. Asp684-Gln702). The hydroxyl side chain of Ser704 occasionally forms a hydrogen bond with the amide group of Ala707. Similarly, in the variant simulations, the hydroxyl side chain of Thr704 forms hydrogen bonds with the amide groups of Ala707 and Leu708. Thus, the residue swap does not cause any apparent structural change.
c.1465C>T	L489F (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33438497-C-T	1	6.20e-7	-12.066	Likely Pathogenic	0.965	Likely Pathogenic	Likely Pathogenic	0.724	Likely Pathogenic	1.72	Ambiguous	0.5	1.14	Ambiguous	1.43	Ambiguous	0.56	Ambiguous	-3.76	Deleterious	1.000	Probably Damaging	0.997	Probably Damaging	-1.51	Pathogenic	0.01	Affected	3.37	35	2	0	-1.0	34.02	246.4	-17.8	0.0	0.0	0.6	0.1						X		Potentially Benign	The iso-butyl side chain of Leu489, located in the α-helix (res. Leu489-Glu519) within an inter-helix space of four helices (res. Ala461-Phe476, res. Val441-Ser457, and res. Met414-Glu436), packs with hydrophobic residues (e.g., Cys432, Ala448, Lys444, Ala493, Val447, Met468) in the inter-helix space. In the variant simulations, the phenyl ring of the Phe489 side chain can also pack favorably in the hydrophobic region. However, due to the size difference, the aromatic side chain of Phe489 tends to reposition to escape the tight region to accommodate the larger side chain, stacking with Lys444. Although no apparent negative changes are observed during the variant simulation, the size difference between the swapped residues could affect the protein folding process.
c.1604G>C	S535T (3D Viewer)	Likely Benign	GAP	Benign		1	6-33438847-G-C	14	8.67e-6	-3.886	Likely Benign	0.069	Likely Benign	Likely Benign	0.177	Likely Benign	0.45	Likely Benign	0.1	-0.27	Likely Benign	0.09	Likely Benign	0.17	Likely Benign	-0.81	Neutral	0.000	Benign	0.001	Benign	-1.25	Pathogenic	0.25	Tolerated	3.37	35	1	1	0.1	14.03	201.3	-17.3	-0.1	0.7	-0.2	0.1						X		Potentially Benign	Ser535 is located near the terminal end of an α-helix (res. Ala533-Val560) close to the membrane interface. In the WT simulations, the hydroxyl side chain of Ser535 forms hydrogen bonds with nearby residues (e.g., His539, Glu538) without any specific interactions. These hydrogen bonds disrupt the structure of the terminal end of the α-helix (Ala533-Ser535), causing it to weaken or unfold during the WT simulations. In the variant simulations, Thr535, a hydrophilic residue with a hydroxyl group of almost the same size as Ser, interacts more frequently with the preceding loop residues (e.g., Thr532, Cys531) due to its longer side chain. Regardless, the residue swap is tolerated in the simulations with no negative effects. However, due to its location near the SynGAP-membrane interface, the effect of the residue swap cannot be fully addressed using the SynGAP solvent-only simulations.	10.1016/j.ajhg.2020.11.011
c.1813C>T	P605S (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-10.830	Likely Pathogenic	0.987	Likely Pathogenic	Likely Pathogenic	0.718	Likely Pathogenic	3.40	Destabilizing	0.1	3.34	Destabilizing	3.37	Destabilizing	1.00	Destabilizing	-7.96	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	0.70	Pathogenic	0.00	Affected	3.37	35	1	-1	0.8	-10.04	213.8	-15.4	-0.3	0.2	0.2	0.1				X			X	Potentially Pathogenic	Pro605 is located in a short turn between an α helix (res. Glu582-Met603) and a short α helical section (res. Ser606-Phe608). The pyrrolidine side chain of Pro605 packs hydrophobically with nearby hydrophobic residues (e.g., Ile514, Leu623, Leu610) in the inter-helix space. Additionally, proline lacks a free backbone amide group, which breaks the α helix and facilitates the turn in the WT structure.In the variant simulations, the hydroxyl side chain of Ser605 forms hydrogen bonds with the backbone carbonyl groups of Ala601 and Ile602. Importantly, the helix end is more stable than with Pro605 in the WT. Indeed, proline is a more effective secondary structure breaker compared to serine.Thus, the residue swap could have a more profound effect on the actual folding process, for example, by preventing the bending at the α helix end, than what the simulations suggest. Moreover, due to its location at the GAP-Ras interface, the residue swap could affect the GAP-Ras association.
c.600G>C	L200F (3D Viewer)		PH	Uncertain		1	6-33435242-G-C	2	1.24e-6	-7.606	In-Between	0.592	Likely Pathogenic	Likely Benign	0.094	Likely Benign	1.00	Ambiguous	0.5	1.45	Ambiguous	1.23	Ambiguous	0.43	Likely Benign	-1.97	Neutral	0.997	Probably Damaging	0.916	Probably Damaging	4.02	Benign	0.17	Tolerated	3.46	9	2	0	-1.0	34.02	250.4	-15.1	0.6	0.2	0.5	0.0						X		Uncertain	Leu200, a hydrophobic residue located in the N-terminal loop before the first anti-parallel β sheet strand (res. Ile205-Pro208), is replaced by another hydrophobic residue, phenylalanine. Both the phenyl group of Phe200 and the branched iso-butyl hydrocarbon sidechain of Leu200 occupy an inward hydrophobic niche (e.g., Leu246, Val222, Phe231) during the simulations. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1055C>A	T352N (3D Viewer)	Likely Benign	C2	Likely Benign		1	6-33437960-C-A	2	1.24e-6	-4.817	Likely Benign	0.117	Likely Benign	Likely Benign	0.027	Likely Benign	0.20	Likely Benign	0.0	-0.04	Likely Benign	0.08	Likely Benign	0.45	Likely Benign	-0.92	Neutral	0.255	Benign	0.057	Benign	1.75	Pathogenic	0.19	Tolerated	3.37	25	0	0	-2.8	13.00	208.4	-14.5	-0.2	0.1	-0.1	0.0		X						Potentially Benign	Thr352 is located in a short α helical section within a loop connecting two β strands (res. Gly341-Pro349, res. Thr359-Pro364) originating from two different anti-parallel β sheets of the C2 domain. In the WT simulations, the side chain hydroxyl and backbone amide groups of Thr354 form hydrogen bonds with the backbone carbonyl group of Pro349 at the end of the preceding β strand. This arrangement likely stabilizes the α helical section and aids in folding, keeping the short secondary structure element intact in the variant simulations. However, the carboxamide group of the Asn352 side chain does not form hydrogen bonds with the backbone carbonyl group of Pro349. Instead, it packs against the cyclic ring and forms hydrogen bonds with the phenol group of the Tyr363 side chain in the other β strand.
c.2143C>T	P715S (3D Viewer)		GAP	Likely Pathogenic		1	6-33441608-C-T	1	6.20e-7	-7.635	In-Between	0.787	Likely Pathogenic	Ambiguous	0.277	Likely Benign	3.54	Destabilizing	0.0	0.81	Ambiguous	2.18	Destabilizing	0.94	Ambiguous	-7.17	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	3.43	Benign	0.01	Affected	3.50	9	1	-1	0.8	-10.04	231.8	-14.0	-0.1	0.0	-0.8	0.1							X	Uncertain	Pro715, along with Gly712 and Pro713, are located in a hinge region of an α-helix making a ~90-degree turn (res. Lys705-Leu725). In the WT simulations, the pyrrolidine side chain of Pro715, lacking the backbone amide groups altogether, forces the tight helix turn to take place while also hydrophobically packing with nearby residues (e.g., Leu700, Leu708, Leu714, and Leu718). Leu715, with a normal amide backbone, could potentially affect protein folding and turn formation, although this was not observed in the variant simulations. Additionally, the hydroxyl group of the Ser715 side chain can form hydrogen bonds with the backbone carbonyl group of Gly712 and disrupt the hydrophobic packing arrangement of the leucine residues from the neighboring α-helices, impacting the GAP domain tertiary assembly.
c.611C>G	S204C (3D Viewer)	Likely Benign	PH	Uncertain		1				-6.613	Likely Benign	0.127	Likely Benign	Likely Benign	0.148	Likely Benign	0.65	Ambiguous	0.4	-1.13	Ambiguous	-0.24	Likely Benign	0.10	Likely Benign	-0.64	Neutral	0.978	Probably Damaging	0.753	Possibly Damaging	4.13	Benign	0.05	Affected	3.44	10	0	-1	3.3	16.06	223.6	-13.8	0.6	0.3	0.0	0.2	X							Uncertain	The hydroxyl-containing Ser204, located in the N-terminal loop before the first anti-parallel β sheet strand (res. Ile205-Pro208), is replaced by the thiol-containing cysteine. In the WT simulations, Ser204 simultaneously forms hydrogen bonds with the backbone carbonyl of Asp201 and the hydroxyl group of Thr224, helping to stabilize the two anti-parallel β strands (res. Ile205-Lys207 and Cys219-Thr223) at the end of the β sheet. Since the thiol group of cysteine forms weaker hydrogen bonds than the hydroxyl group of serine, Cys204 does not maintain the hydrogen bond network as stably as Ser204 in the variant simulations. However, because the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1621G>C	A541P (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.733	Likely Pathogenic	0.996	Likely Pathogenic	Likely Pathogenic	0.594	Likely Pathogenic	2.47	Destabilizing	0.3	7.26	Destabilizing	4.87	Destabilizing	0.86	Ambiguous	-3.16	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	-1.34	Pathogenic	0.07	Tolerated	3.37	35	1	-1	-3.4	26.04	170.4	-11.2	0.1	0.0	0.1	0.0	X							Potentially Pathogenic	Ala541 is located on the outer surface of an α-helix (res. Ala533-Val560). The methyl group of Ala541 is on the surface and does not form any interactions. Proline lacks a free backbone amide group, and thus, Pro541 is unable to form a hydrogen bond with the carbonyl group of Ala537 in the variant simulations. Consequently, Pro541 disrupts the continuity of the secondary structure element, causing the α-helix to bend slightly in the variant simulations.
c.1658A>C	K553T (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-15.328	Likely Pathogenic	0.990	Likely Pathogenic	Likely Pathogenic	0.761	Likely Pathogenic	1.06	Ambiguous	0.2	0.48	Likely Benign	0.77	Ambiguous	0.79	Ambiguous	-5.77	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.34	Pathogenic	0.14	Tolerated	3.37	35	0	-1	3.2	-27.07	218.2	-10.7	0.0	0.0	-0.2	0.5		X						Potentially Pathogenic	Lys533 is located on an α-helix (res. Ala533-Val560). In the WT simulations, Lys533 packs against Phe513, and its amino side chain occasionally forms an ionic interaction with the carboxylate group of Glu512 from an opposing α-helix (res. Gln503-Tyr518). In the variant simulations, Thr533 is unable to reproduce these interactions, potentially weakening the integrity of the tertiary structure. Additionally, Thr533 forms a hydrogen bond with the backbone carbonyl group of Leu549 in the same helix, which could potentially weaken the secondary structure. Regardless, the residue swap does not cause significant structural effects based on the simulations.
c.958G>C	V320L (3D Viewer)		C2	Uncertain		1	6-33437863-G-C	6	3.72e-6	-6.207	Likely Benign	0.362	Ambiguous	Likely Benign	0.096	Likely Benign	-0.26	Likely Benign	0.2	1.33	Ambiguous	0.54	Ambiguous	0.51	Ambiguous	-1.02	Neutral	0.900	Possibly Damaging	0.373	Benign	1.78	Pathogenic	0.92	Tolerated	3.38	23	2	1	-0.4	14.03	245.8	-10.2	0.3	0.9	0.1	0.3						X		Potentially Benign	The isopropyl side chain of Val310, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Thr305-Asn315, res. Ala322-Asp330), hydrophobically packs with the side chains of nearby residues (e.g., Leu286, Val350, Pro318). The hydrophobic Leu320 side chain mostly forms the same interactions; hence, the residue swap does not seem to negatively affect the protein structure based on the variant simulations.
c.1771G>C	A591P (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.479	Likely Pathogenic	0.991	Likely Pathogenic	Likely Pathogenic	0.404	Likely Benign	3.78	Destabilizing	0.3	7.29	Destabilizing	5.54	Destabilizing	1.45	Destabilizing	-4.41	Deleterious	0.995	Probably Damaging	0.853	Possibly Damaging	3.35	Benign	0.01	Affected	3.37	35	1	-1	-3.4	26.04	191.5	-10.1	0.2	0.1	0.4	0.1	X							Potentially Pathogenic	The methyl group of the Ala591 side chain, located in the middle of an α helix (res. Glu582-Met603), packs against hydrophobic residues (e.g., Ile483, Phe484) of an opposing partially helical loop (res. Phe476-Asn487).In the variant simulations, Pro591 lacks a free backbone amide group and, therefore, cannot form a hydrogen bond with the backbone carbonyl of Arg587 as Ala591 does in the WT. This notably weakens the α helix integrity and compromises the continuity of the helix. In reality, the effect on the structure during protein folding could be more severe.
c.1925A>C	K642T (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-12.823	Likely Pathogenic	0.948	Likely Pathogenic	Ambiguous	0.484	Likely Benign	0.53	Ambiguous	0.1	0.30	Likely Benign	0.42	Likely Benign	0.28	Likely Benign	-5.88	Deleterious	0.872	Possibly Damaging	0.839	Possibly Damaging	2.86	Benign	0.00	Affected	3.37	31	0	-1	3.2	-27.07	213.5	-8.7	-0.3	0.4	0.3	0.2				X				Uncertain	The amino side chain of Lys642, located on the surface of an α helix (res. Ser641-Glu666), is not involved in any interactions in the WT simulations. In the variant simulations, the shorter side chain of Thr642 forms hydrogen bonds with Glu643 and Thr640 on the same α helix.Regardless, Lys642 is positioned directly at the GAP-Ras interface, and in the SynGAP-Ras WT simulations, its amino side chain forms salt bridges with the carboxylate groups of Ras residues Asp33 and Asp38. The shorter Thr642 is more likely to prefer hydrogen bonding with Glu643 and Thr640 on the same α helix, even in the Ras complex. Thus, the effect of the residue swap on the complex formation with the GTPase cannot be explored using solvent-only simulations.
c.1964T>A	L655Q (3D Viewer)	Likely Benign	GAP	Uncertain		1				-5.278	Likely Benign	0.144	Likely Benign	Likely Benign	0.139	Likely Benign	-0.01	Likely Benign	0.0	0.69	Ambiguous	0.34	Likely Benign	-0.15	Likely Benign	0.61	Neutral	0.955	Possibly Damaging	0.602	Possibly Damaging	3.59	Benign	0.65	Tolerated	3.39	24	-2	-2	-7.3	14.97	229.9	-8.6	0.0	0.0	0.4	0.0						X		Potentially Benign	The iso-butyl side chain of Leu655, located on the surface of an α helix (res. Ser641-Glu666), is not involved in any interactions in the WT simulations. In the variant simulations, the carboxamide side chain of Gln655 dynamically interacts with neighboring residues (e.g., Glu651, Glu656, Arg544) on the protein surface, with no negative structural effects.
c.791T>A	L264Q (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-15.729	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.678	Likely Pathogenic	3.43	Destabilizing	0.1	2.41	Destabilizing	2.92	Destabilizing	2.48	Destabilizing	-5.52	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	0.49	Pathogenic	0.00	Affected	3.38	18	-2	-2	-7.3	14.97	254.7	-7.6	0.0	0.0	0.0	0.3	X		X				X	Potentially Pathogenic	The iso-butyl branched hydrocarbon side chain of Leu264, located at the end of an anti-parallel β sheet strand (res. Arg259-Arg272), packs against multiple hydrophobic residues such as Leu266, Phe314, Leu317, and Leu323 in the WT simulations. In the variant simulations, the hydrophilic carboxamide group of the Gln264 side chain is not suitable for the hydrophobic niche, causing the hydrophobic residues to make room for the swapped residue. Additionally, the carboxamide group of Gln264 forms hydrogen bonds with the backbone amide groups of Arg405 and Lys256 in the β sheet and the carbonyl group of Val350 in an α helical section of a nearby loop (res. Pro359-Phe358). The residue swap disrupts the packing of the C2 domain, which could adversely affect the C2 domain structure during folding. This disruption could potentially weaken the stability of the SynGAP-membrane association.
c.1966G>C	E656Q (3D Viewer)		GAP	Uncertain		1	6-33441225-G-C	1	6.20e-7	-9.145	Likely Pathogenic	0.766	Likely Pathogenic	Likely Benign	0.249	Likely Benign	-0.14	Likely Benign	0.0	-0.81	Ambiguous	-0.48	Likely Benign	0.25	Likely Benign	-2.29	Neutral	0.980	Probably Damaging	0.528	Possibly Damaging	3.46	Benign	0.02	Affected	3.39	24	2	2	0.0	-0.98	224.3	1.7	0.0	0.1	0.1	0.0		X						Potentially Benign	The carboxylate side chain of Glu656, located on an α helix (res. Ser641-Glu666), frequently forms a hydrogen bond with the nearby residue Ser659 on the same α helix. In the variant simulations, the carboxamide side chain of Gln656 alternatively forms a hydrogen bond with either Ser659 or Glu548 on an opposing helix (res. Ala533-Val560).Although the frequent interaction between Gln656 and Glu548 may strengthen or stabilize the tertiary structure assembly, the effect is likely to be marginal.
c.821T>A	L274Q (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-15.518	Likely Pathogenic	0.995	Likely Pathogenic	Likely Pathogenic	0.774	Likely Pathogenic	2.54	Destabilizing	0.3	1.74	Ambiguous	2.14	Destabilizing	1.97	Destabilizing	-5.42	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	0.00	Pathogenic	0.00	Affected	3.38	19	-2	-2	-7.3	14.97	245.9	1.8	0.0	0.0	0.1	0.2	X		X				X	Potentially Pathogenic	The aliphatic side chain of Leu274, located in a β hairpin loop (res. Glu273-Lys278) connecting two anti-parallel β sheet strands, packs against multiple hydrophobic residues facing the β sheet (e.g., Ala271, Leu327, Tyr280, Val306). The hydrophilic carboxamide group of the Gln274 side chain is not suitable for this hydrophobic niche, causing nearby residues to adjust to make room for the hydrophilic glutamine. Additionally, a new hydrogen bond forms with the backbone carboxyl group of Arg272 in another β strand (res. Glu273-Arg259).As a result, the backbone amide group of Ala399 and the carbonyl group of Arg272, which connect two β strands at the β sheet end, form fewer hydrogen bonds in the variant than in the WT simulations. Although no major secondary structure disruption is observed in the variant simulations, the residue swap could profoundly affect the C2 domain folding, as the hydrophobic packing of Leu274 is crucial for maintaining the loop's contact with the rest of the C2 domain. Lastly, because the Leu274-containing loop faces the membrane surface, the residue swap could also negatively impact the SynGAP-membrane association.
c.859G>C	D287H (3D Viewer)	Likely Pathogenic	C2	Likely Pathogenic		1				-14.518	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.589	Likely Pathogenic	0.48	Likely Benign	0.3	0.32	Likely Benign	0.40	Likely Benign	0.63	Ambiguous	-6.43	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.51	Pathogenic	0.00	Affected	3.38	23	1	-1	0.3	22.05	235.6	3.8	0.1	1.2	0.1	0.1	X	X						Potentially Pathogenic	The carboxylate group of Asp287, located at the beginning of a β hairpin loop connecting two anti-parallel β sheet strands (res. Arg279-Leu286, res. Met289-Pro298), maintains a salt bridge with the guanidinium group of Arg324 in the β sheet during the WT simulations. In the variant simulations, the imidazole ring of the His287 side chain is unable to form a salt bridge with Arg324 or establish any other stable compensatory interactions, which could weaken the beta sandwich assembly of the C2 domain. This destabilization of the C2 domain could adversely affect the stability of the SynGAP-membrane association.
c.2015C>A	T672K (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-12.192	Likely Pathogenic	0.698	Likely Pathogenic	Likely Benign	0.065	Likely Benign	0.20	Likely Benign	0.5	1.21	Ambiguous	0.71	Ambiguous	0.72	Ambiguous	-4.31	Deleterious	0.745	Possibly Damaging	0.051	Benign	3.40	Benign	0.07	Tolerated	3.40	25	0	-1	-3.2	27.07	195.1	7.0	0.4	0.7	0.4	0.1		X				X		Potentially Pathogenic	The hydroxyl group of Thr672, located in an entangled α-α loop connecting the two α-helices (res. Ser641-Glu666 and res. Leu685-Val699), is involved in a highly coordinated hydrogen-bonding network between residues from two α-helices (res. Ser641-Glu666 and res. Arg563-Glu578) and from the α-α loop itself, such as Lys566, Glu666, and Asn669. In the variant simulations, Lys672 can only form a hydrogen bond with the amino group of the Lys566 side chain via its backbone carbonyl group. Consequently, it cannot maintain the Lys566-Glu666 salt bridge through hydrogen bonding. However, the amino group of Lys periodically forms a salt bridge with the carboxylate group of Glu666, which prevents a drastic disruption of the hydrogen-bond network that keeps the loop close to the helices.
c.1260T>G	F420L (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-8.432	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.146	Likely Benign	1.76	Ambiguous	0.0	1.41	Ambiguous	1.59	Ambiguous	1.04	Destabilizing	-5.39	Deleterious	0.009	Benign	0.005	Benign	4.22	Benign	0.39	Tolerated	3.37	29	2	0	1.0	-34.02	231.1	13.2	0.0	0.0	-0.1	0.0						X		Potentially Benign	In the WT, the phenyl ring of the Phe420 side chain, located on an α helix (res. Met414-Glu436), packs against hydrophobic residues in the interhelix area of the GAP domain (e.g., Leu689, Leu714, Leu717, Leu718). In the variant simulations, the iso-butyl side chain of Leu420 also packs into the hydrophobic inter-helix niche, but due to its smaller size, the resulting steric interactions are not as favorable as with phenylalanine. In short, the residue swap does not cause severe effects on the protein structure based on the variant simulations.
c.844T>A	C282S (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-11.846	Likely Pathogenic	0.958	Likely Pathogenic	Likely Pathogenic	0.460	Likely Benign	1.55	Ambiguous	0.1	1.23	Ambiguous	1.39	Ambiguous	1.62	Destabilizing	-9.19	Deleterious	0.997	Probably Damaging	0.994	Probably Damaging	1.64	Pathogenic	0.03	Affected	3.39	18	0	-1	-3.3	-16.06	233.2	14.8	-0.1	0.0	-0.2	0.3						X		Potentially Benign	The thiol-containing side chain of Cys282, located at the beginning of an anti-parallel β sheet strand (res. Arg279-Leu286), packs against multiple hydrophobic residues (e.g., Ile268, Leu284, Trp308, Leu327). In the variant simulations, the hydroxyl-containing side chain of Ser282 is more hydrophilic and, hence, not as favorable as Cys282 for this hydrophobic niche. Due to this polarity difference, the residue swap could potentially weaken the hydrophobic packing of the C2 domain during the folding process.Moreover, because the C2 domain interacts with the membrane, there could also be a negative effect on the stability of the SynGAP-membrane association. However, no large-scale structural changes were observed during the variant simulations. The hydroxyl group of Ser282 forms a hydrogen bond with the backbone carbonyl group of His326 in another β strand (res. Ala322-Arg329), which competes directly with the backbone amide group of Glu283 within the secondary structure element.
c.2068T>C	S690P (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.568	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.431	Likely Benign	4.84	Destabilizing	0.3	4.40	Destabilizing	4.62	Destabilizing	1.42	Destabilizing	-4.77	Deleterious	0.998	Probably Damaging	0.790	Possibly Damaging	3.44	Benign	0.01	Affected	3.42	17	1	-1	-0.8	10.04	207.5	15.1	0.1	0.0	-0.1	0.2	X	X						Potentially Pathogenic	The hydroxyl side chain of Ser690, located in an α-helix (res. Leu696-Leu685), forms a hydrogen bond with the backbone carbonyl group of Ser410 in an anti-parallel β-sheet of the C2 domain (res. Ile411-Ala399). In the variant simulations, the pyrrolidine side chain of Pro690 cannot form hydrogen bonds with the C2 domain residue, resulting in the loss of this inter-domain connection. Additionally, prolines lack a free amide group necessary for hydrogen bonding with the carbonyl group of Gly686, introducing a slight bend in the α-helix and compromising its integrity.
c.1428C>G	F476L (3D Viewer)		GAP	Uncertain		2	6-33438460-C-G	4	2.48e-6	-10.109	Likely Pathogenic	0.994	Likely Pathogenic	Likely Pathogenic	0.180	Likely Benign	1.00	Ambiguous	0.1	1.04	Ambiguous	1.02	Ambiguous	0.75	Ambiguous	-1.10	Neutral	0.997	Probably Damaging	0.978	Probably Damaging	3.53	Benign	0.60	Tolerated	3.40	22	2	0	1.0	-34.02	235.9	16.1	0.0	0.1	-0.2	0.0	X							Potentially Benign	In the WT simulations, the phenyl ring of Phe476, located at the end of an α-helix (res. Ala461-Phe476), packs with the hydrophobic side chains of Leu482 and Ile483. Additionally, Phe476 stacks with the Arg475 side chain on the preceding α-α loop connecting the two α-helices (res. Ala461-Phe476 and res. Leu489-Glu519) near the GAP-Ras interface.In the variant simulations, Leu476 can maintain hydrophobic packing with neighboring residues, although not as efficiently as the phenylalanine in the WT system. The absence of Phe476/Arg475 stacking weakens the integrity of the α-helix end in the variant simulations. Nonetheless, no large-scale adverse effects are observed in the simulations. Lastly, the potential effect of the residue swap on SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations.
c.1998G>C	E666D (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-8.820	Likely Pathogenic	0.704	Likely Pathogenic	Likely Benign	0.197	Likely Benign	0.88	Ambiguous	0.0	0.37	Likely Benign	0.63	Ambiguous	1.05	Destabilizing	-2.69	Deleterious	0.992	Probably Damaging	0.603	Possibly Damaging	3.43	Benign	0.06	Tolerated	3.38	28	3	2	0.0	-14.03	237.2	16.5	0.0	0.0	-0.3	0.1		X						Potentially Pathogenic	The carboxylate group of Glu666, located on the α-helix (res. Ser641-Glu666), is involved in a highly coordinated hydrogen-bonding network between residues from two α-helices (res. Ser641-Glu666 and res. Arg563-Glu578) and from the α-α loop connecting the two α-helices (res. Ser641-Glu666 and res. Leu685-Val699), such as Lys566, Thr672, and Asn669, in the WT simulations. In the variant simulations, the shorter side chain of Asp666 cannot maintain these interactions as efficiently as Glu666 in the WT, resulting in a less coordinated hydrogen-bond network.
c.703T>C	S235P (3D Viewer)	Likely Pathogenic	PH	Likely Pathogenic		1				-14.857	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.870	Likely Pathogenic	4.02	Destabilizing	0.1	6.91	Destabilizing	5.47	Destabilizing	1.23	Destabilizing	-4.24	Deleterious	0.917	Possibly Damaging	0.446	Benign	5.47	Benign	0.01	Affected	3.40	14	1	-1	-0.8	10.04	201.5	17.0	0.1	0.0	-0.6	0.0		X						Potentially Pathogenic	In the WT, the hydroxyl group of Ser235, located in a β-α loop between an anti-parallel β sheet strand (res. Gly227-Phe231) and an α helix (residues Ala236-Val250), forms hydrogen bonds with the GAP domain loop residue Glu680 and with the backbone amide groups of Ala237 and Glu238 from the α helix. In the variant simulations, the pyrrolidine ring of Pro235 cannot stabilize the α helix end or maintain tertiary bonding interactions between the PH and GAP domains via hydrogen bonding as effectively as serine.
c.667A>T	T223S (3D Viewer)		PH	Conflicting		2	6-33435518-A-T	3	1.86e-6	-7.714	In-Between	0.410	Ambiguous	Likely Benign	0.535	Likely Pathogenic	0.26	Likely Benign	0.1	0.50	Ambiguous	0.38	Likely Benign	0.62	Ambiguous	-2.86	Deleterious	0.421	Benign	0.058	Benign	5.80	Benign	0.02	Affected	3.41	13	1	1	-0.1	-14.03	200.7	17.3	-0.2	0.2	0.0	0.0						X		Uncertain	The introduced residue Ser223 is located on the outer surface of an anti-parallel β sheet strand (res. Cys219-Thr224). Its hydroxyl group forms hydrogen bonds with nearby residues Thr228 and Lys207 in the variant simulations, similar to the hydroxyl group of Thr223 in the WT simulations. These hydrogen-bonding interactions at the β sheet surface contribute to the stability of the secondary structure element and may prevent it from unfolding. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1408A>C	M470L (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33438440-A-C	1	6.20e-7	-8.993	Likely Pathogenic	0.406	Ambiguous	Likely Benign	0.678	Likely Pathogenic	0.73	Ambiguous	0.1	0.84	Ambiguous	0.79	Ambiguous	1.04	Destabilizing	-2.72	Deleterious	0.484	Possibly Damaging	0.654	Possibly Damaging	-1.22	Pathogenic	0.16	Tolerated	3.37	34	4	2	1.9	-18.03	225.3	17.9	0.0	0.0	-0.8	0.5						X		Potentially Benign	The thioether group of Met470, located in the middle of an α helix (res. Ala461–Phe476), interacts with hydrophobic residues in the inter-helix space (e.g., Val473, Leu558) formed by two other α helices (res. Ser604–Arg581, res. Pro562–Arg579). In the WT simulations, Met470 also packs against the positively charged guanidinium groups of Arg575, Arg429, and Arg579, which form salt bridges with the negatively charged carboxylate groups of the Asp474 and Asp467 side chains at the protein surface. In the variant simulations, the iso-butyl side chain of Leu470 packs similarly with the hydrophobic residues as methionine, resulting in no negative effects on the protein structure during the simulation.
c.1153T>C	S385P (3D Viewer)	Likely Benign	C2	Uncertain		1	6-33438058-T-C			-5.431	Likely Benign	0.123	Likely Benign	Likely Benign	0.385	Likely Benign	0.91	Ambiguous	0.6	-0.90	Ambiguous	0.01	Likely Benign	0.19	Likely Benign	-0.26	Neutral	0.676	Possibly Damaging	0.693	Possibly Damaging	4.63	Benign	0.04	Affected	4.32	3	1	-1	-0.8	10.04	210.3	18.5	1.8	0.9	0.3	0.0								Uncertain	Ser385 is located in the Gly-rich Ω loop (res. Pro364-Pro398) between two anti-parallel β sheet strands (res. Thr359-Pro364, res. Ala399-Ile411). Because the Ω loop is assumed to directly interact with the membrane, it moves arbitrarily throughout the WT solvent simulations. The Ω loop potentially plays a crucial role in the SynGAP-membrane complex association, stability, and dynamics. However, this aspect cannot be fully addressed through solvent simulations alone.Ω loops are known to play major roles in protein functions that require flexibility, and so they are rich in glycine residues, prolines, and, to a lesser extent, small hydrophilic residues to ensure maximum flexibility. Thus, the variant’s Pro385 is potentially tolerated in the Ω loop. However, since the effects on Gly-rich Ω loop dynamics can only be well studied through the SynGAP-membrane complex, no definite conclusions can be drawn.
c.1778T>A	L593H (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-16.504	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.812	Likely Pathogenic	2.52	Destabilizing	0.2	2.32	Destabilizing	2.42	Destabilizing	2.75	Destabilizing	-6.77	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.77	Benign	0.00	Affected	3.37	35	-2	-3	-7.0	23.98	222.0	20.7	0.0	0.0	0.2	0.0		X					X	Potentially Pathogenic	The iso-propyl side chain of Leu593, located in an α helix (res. Glu582-Met603), packs favourably with multiple hydrophobic residues in the inter-helix space (e.g., Leu598, Ile589, Phe594, Phe561).In the variant simulations, His593 retains a similar packing arrangement via its aromatic imidazole ring. However, the polar nitrogen atoms introduce hydrogen bond donors and acceptors into the previously hydrophobic space. The epsilon protonated nitrogen of His593 forms a stable hydrogen bond with the phenol group of the Tyr505 side chain in an α helix (res. Gln503-Tyr518).While the residue swap could affect the tertiary assembly and the underlying protein folding process, it is difficult to determine if the mutation would be tolerated based solely on the variant simulations.
c.1763T>A	L588H (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-16.947	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.939	Likely Pathogenic	4.20	Destabilizing	0.2	3.69	Destabilizing	3.95	Destabilizing	2.26	Destabilizing	-6.97	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.42	Pathogenic	0.00	Affected	3.38	34	-2	-3	-7.0	23.98	214.3	20.9	0.0	0.0	0.0	0.2	X	X					X	Potentially Pathogenic	The isobutyl group of the Leu588 side chain, located in an α helix (res. Glu582-Met603), packs against hydrophobic residues in the inter-helix hydrophobic space (e.g., Ile584, Trp572, Phe484, Met470, Val473, Ile483).In the variant simulations, the imidazole ring of His588 is aromatic but contains polar delta and epsilon nitrogen atoms that are not suited for the hydrophobic niche. The protonated epsilon nitrogen forms a hydrogen bond with the backbone carbonyl group of Ala469, which can disrupt the continuity of the opposing α helix (res. Phe476-Lys460).While the residue swap could affect the tertiary assembly and the underlying protein folding process, it is difficult to determine if the mutation would be tolerated based solely on the variant simulations.
c.1947G>C	M649I (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-9.361	Likely Pathogenic	0.995	Likely Pathogenic	Likely Pathogenic	0.449	Likely Benign	2.42	Destabilizing	0.2	1.96	Ambiguous	2.19	Destabilizing	1.01	Destabilizing	-3.99	Deleterious	0.672	Possibly Damaging	0.093	Benign	3.40	Benign	0.02	Affected	3.38	27	2	1	2.6	-18.03	243.7	21.5	0.0	0.1	0.0	0.1							X	Potentially Benign	The thioether side chain of Met649, located on an α helix (res. Ser641-Glu666), bridges Phe652, Phe648, and Phe639 in an inter-helix hydrophobic cavity in the WT simulations. In the variant simulations, the sec-butyl side chain of Ile649 maintains hydrophobic interactions with nearby residues, with no significant effects on the protein structure.However, methionine is known as a bridging motif for aromatic residues, and these Met-aromatic interactions are lost in the variant. Indeed, in the second variant simulation,the bridging of Phe652, Phe648 and Phe639 is completely lost. In reality, the effect could be more severe on the structure during the protein folding.
c.597C>A	N199K (3D Viewer)		PH	Uncertain		1				-8.198	Likely Pathogenic	0.686	Likely Pathogenic	Likely Benign	0.024	Likely Benign	-0.19	Likely Benign	0.1	0.03	Likely Benign	-0.08	Likely Benign	0.33	Likely Benign	-1.48	Neutral	0.276	Benign	0.083	Benign	4.27	Benign	0.13	Tolerated	3.47	9	1	0	-0.4	14.07	207.8	21.5	-0.1	1.5	0.1	0.0						X		Uncertain	Asn199, located in the N-terminal loop before the first anti-parallel β sheet strand (res. Ile205-Pro208), is replaced by a positively charged lysine. On the protein surface, both the carboxamide group of Asn199 and the amino group of Lys199 side chains can form hydrogen bonds with the backbone carbonyl groups of residues (e.g., Ala249) at the end of an α helix (res. Ala236-Lys251). However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.819G>T	E273D (3D Viewer)	Likely Benign	C2	Benign		1	6-33437724-G-T	2	1.24e-6	-1.811	Likely Benign	0.058	Likely Benign	Likely Benign	0.092	Likely Benign	0.26	Likely Benign	0.1	-0.48	Likely Benign	-0.11	Likely Benign	-0.63	Ambiguous	1.99	Neutral	0.004	Benign	0.010	Benign	2.00	Pathogenic	1.00	Tolerated	3.38	18	3	2	0.0	-14.03	223.1	22.1	0.2	0.0	0.0	0.1						X		Potentially Benign	The negatively charged residue Glu273, located in a β hairpin loop (res. Glu273-Lys278) that connects two anti-parallel β sheet strands, is replaced with another negatively charged residue, aspartate. Because the C2 domain loop faces the membrane surface, the potentially crucial role of the carboxylate group of Glu273 or Asp273 on SynGAP-membrane association cannot be fully explored via solvent-only simulations.As a minor note, the neighboring residue Arg272, which stacks with the indole ring of the Trp362 side chain and directly faces RasGTPase, forms a salt bridge more often with Asp273 than with the non-mutated Glu273 in the simulations. Regardless, due to the similar physicochemical properties of the WT and variant residues at the membrane interface, the residue swap is likely to be well tolerated.
c.1622C>G	A541G (3D Viewer)		GAP	Uncertain		1	6-33438865-C-G	2	1.24e-6	-7.233	In-Between	0.341	Ambiguous	Likely Benign	0.421	Likely Benign	0.67	Ambiguous	0.0	0.94	Ambiguous	0.81	Ambiguous	0.76	Ambiguous	-1.48	Neutral	0.999	Probably Damaging	0.995	Probably Damaging	-1.31	Pathogenic	0.57	Tolerated	3.37	35	1	0	-2.2	-14.03	170.1	23.6	0.0	0.0	0.0	0.0	X							Potentially Pathogenic	Ala541 is located on the outer surface of an α-helix (res. Ala533-Val560). The methyl group of Ala541 is on the surface and does not form any interactions. Glycine, known as an “α-helix breaker,” weakens the integrity of the helix. Indeed, in the variant simulations, the hydrogen bond formation between Gly541 and the backbone carbonyl of Ala537 is disrupted.
c.1730C>G	A577G (3D Viewer)	Likely Benign	GAP	Benign/Likely benign		2	6-33440782-C-G	1	6.20e-7	-5.717	Likely Benign	0.268	Likely Benign	Likely Benign	0.443	Likely Benign	0.83	Ambiguous	0.0	1.02	Ambiguous	0.93	Ambiguous	0.86	Ambiguous	-1.84	Neutral	0.997	Probably Damaging	0.990	Probably Damaging	-1.31	Pathogenic	0.31	Tolerated	3.37	34	1	0	-2.2	-14.03	158.7	23.6	0.0	0.0	0.0	0.0						X		Potentially Benign	Ala577 is located near the end and outer surface of an α-helix (res. Arg563-Glu578), where its methyl group does not form any particular interactions in the WT simulations. The introduced residue, glycine, is known as an “α-helix breaker.” However, the residue swap caused only minor helix shortening in one of the replica simulations for the variant system. Regardless, the residue swap seems to be well tolerated based on the variant simulations.
c.1888A>G	I630V (3D Viewer)		GAP	Benign/Likely benign		4	6-33440940-A-G	59	3.66e-5	-7.264	In-Between	0.145	Likely Benign	Likely Benign	0.143	Likely Benign	1.33	Ambiguous	0.0	0.94	Ambiguous	1.14	Ambiguous	0.64	Ambiguous	-0.38	Neutral	0.018	Benign	0.011	Benign	-1.37	Pathogenic	0.35	Tolerated	3.37	34	4	3	-0.3	-14.03	235.0	26.2	-0.1	0.0	-0.3	0.1						X		Potentially Benign	The sec-butyl side chain of Ile630, located in an α helix (res. Glu617-Asn635), packs with hydrophobic residues (e.g., Phe594, Leu633, Ile626, Ile602) in the hydrophobic inter-helix space between two α helices (res. Glu617-Asn635 and res. Glu582-Met603).In the variant simulations, the iso-propyl side chain of Val630, which shares a similar size and physicochemical properties with Ile630 in the WT, maintains similar interactions in the inter-helix space. Although no negative structural effects are observed during the simulations, the implications of the residue swap on the complex formation with the GTPase, due to its location, cannot be investigated using solvent-only simulations.
c.1606T>G	L536V (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-9.014	Likely Pathogenic	0.269	Likely Benign	Likely Benign	0.586	Likely Pathogenic	1.25	Ambiguous	0.3	1.22	Ambiguous	1.24	Ambiguous	1.20	Destabilizing	-2.81	Deleterious	0.998	Probably Damaging	0.992	Probably Damaging	-1.34	Pathogenic	0.09	Tolerated	3.37	34	2	1	0.4	-14.03	204.7	26.4	0.2	0.0	-0.2	0.2						X		Potentially Benign	Leu536 is located on an α-helix (res. Ala533-Val560) at the membrane interface. The iso-butyl group of Leu536 interacts with nearby hydrophobic residues in the preceding loop (e.g., Val526, Pro528, Cys531). In the variant simulations, the iso-propyl side chain of Val536 forms similar hydrophobic interactions as Leu536 in the WT, causing no negative structural effects.
c.886T>G	S296A (3D Viewer)	Likely Benign	C2	Uncertain		1				-6.847	Likely Benign	0.247	Likely Benign	Likely Benign	0.209	Likely Benign	0.50	Ambiguous	0.3	-0.26	Likely Benign	0.12	Likely Benign	0.35	Likely Benign	-1.79	Neutral	0.992	Probably Damaging	0.987	Probably Damaging	1.97	Pathogenic	0.65	Tolerated	3.40	16	1	1	2.6	-16.00	182.5	26.6	-0.2	0.1	-0.5	0.0		X						Potentially Pathogenic	The hydroxyl group of the Ser296 side chain, located in an anti-parallel β sheet strand (res. Met289-Pro298), stably hydrogen bonds with the carboxylate group of Asp330 in a neighboring β strand (res. Ala322-Asp332). The backbone carbonyl group of Ser296 also hydrogen bonds with the guanidinium group of Arg279 in another nearby β strand (res. Arg279-Cys285). In the variant simulations, the methyl group of the Ala296 side chain cannot hydrogen bond with Asp330, causing the carboxylate group positioning to fluctuate more than in the WT simulations.Although the residue swap does not seem to affect the anti-parallel β sheet assembly during the simulations, it is possible that the Ser296-Asp330 hydrogen bond plays a crucial role in maintaining the C2 domain fold. Notably, because Ser296 is located near the membrane interface, the potential effect of the residue swap on the SynGAP-membrane association cannot be addressed by solvent-only simulations.
c.1502T>C	I501T (3D Viewer)	Likely Benign	GAP	Uncertain		1				-5.996	Likely Benign	0.252	Likely Benign	Likely Benign	0.362	Likely Benign	2.40	Destabilizing	0.1	1.81	Ambiguous	2.11	Destabilizing	1.57	Destabilizing	-3.48	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	3.44	Benign	0.16	Tolerated	3.37	35	0	-1	-5.2	-12.05	214.5	26.9	0.0	0.0	0.5	0.0							X	Potentially Pathogenic	Ile501 is located near a hinge in the middle of an α-helix (res. Leu489-Glu519). The sec-butyl side chain of Ile501 is hydrophobically packed with other residues in the inter-helix space (e.g., Leu500, Tyr497, Phe679) in the WT simulations. In the variant simulations, the hydroxyl group of Thr501 forms a hydrogen bond with the backbone atoms of Tyr497 on the same α-helix, which may weaken the α-helix integrity. Additionally, the polar hydroxyl group of Thr501 is not suitable for the hydrophobic inter-helix space, and thus, the residue swap could affect protein folding. However, Ile501 is followed by Gly502, which facilitates a hinge in the middle of the α-helix, making further weakening caused by Thr501 unlikely to be harmful to the α-helix integrity.
c.930G>C	E310D (3D Viewer)	Likely Pathogenic	C2	Likely Pathogenic		1				-11.218	Likely Pathogenic	0.994	Likely Pathogenic	Likely Pathogenic	0.666	Likely Pathogenic	1.87	Ambiguous	0.5	2.39	Destabilizing	2.13	Destabilizing	1.04	Destabilizing	-2.76	Deleterious	0.997	Probably Damaging	0.992	Probably Damaging	1.19	Pathogenic	0.02	Affected	3.38	19	3	2	0.0	-14.03	232.6	27.2	0.1	0.0	0.1	0.1						X		Potentially Benign	The carboxylate group of Glu310, located in an anti-parallel β sheet strand (res. Thr305-Asn315), is ideally positioned to interact with the hydroxyl and backbone amide groups of Thr295 on a twisted anti-parallel β strand. Because the carboxylate group can also interact with the GAP domain residues (e.g., Gln612, Tyr614), Glu310 potentially plays a key role in maintaining the tertiary assembly between the C2 and GAP domains. In the variant simulations, the carboxylate group of Asp310 can form the same interactions as glutamate; however, due to its one hydrocarbon shorter length, the connections are less stable or less optimal.
c.1819C>G	L607V (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33440871-C-G	2	1.24e-6	-11.190	Likely Pathogenic	0.637	Likely Pathogenic	Likely Benign	0.715	Likely Pathogenic	1.04	Ambiguous	0.2	1.36	Ambiguous	1.20	Ambiguous	0.90	Ambiguous	-2.99	Deleterious	0.985	Probably Damaging	0.992	Probably Damaging	-1.50	Pathogenic	0.01	Affected	3.37	35	2	1	0.4	-14.03	216.3	28.1	0.1	0.0	0.9	0.2				X				Potentially Benign	Leu607 is located in a short helical region (res. Ser606-Phe608) within an α-α loop connecting two α helices (res. Glu582-Met603 and res. Glu617-Asn635). In the WT simulations, the iso-butyl side chain of Leu607 does not interact with any other residues, but it could potentially interact directly with Ras due to its location at the GAP domain.In the variant simulations, Val607, which has similar size and physicochemical properties to leucine, does not cause any negative effects on the protein structure. However, due to its location at the GAP-Ras interface, the residue swap could affect the complex formation with the GTPase, but this cannot be investigated using solvent-only simulations.
c.1231A>G	I411V (3D Viewer)	Likely Benign	GAP	Likely Benign		1				-6.290	Likely Benign	0.385	Ambiguous	Likely Benign	0.212	Likely Benign	0.74	Ambiguous	0.0	0.82	Ambiguous	0.78	Ambiguous	0.99	Ambiguous	-0.86	Neutral	0.935	Possibly Damaging	0.858	Possibly Damaging	3.90	Benign	0.27	Tolerated	3.38	28	4	3	-0.3	-14.03	233.3	28.2	-0.2	0.0	-0.2	0.0						X		Potentially Benign	The sec-butyl side chain of Ile411, located in the hydrophobic space between an anti-parallel β sheet strand (res. Pro398-Ile411) and an α helix (res. Asp684-Gln702), packs against multiple residues (e.g., Met409, Arg259). In the variant simulations, the side chain of Val411 is able to favorably fill the same hydrophobic niche despite its slightly smaller size. In short, the residue swap has no apparent negative effect on the structure based on the simulations.
c.2047A>G	I683V (3D Viewer)	Likely Benign	GAP	Uncertain		1	6-33441306-A-G	2	1.24e-6	-7.588	In-Between	0.138	Likely Benign	Likely Benign	0.112	Likely Benign	0.90	Ambiguous	0.0	0.60	Ambiguous	0.75	Ambiguous	0.76	Ambiguous	-0.78	Neutral	0.538	Possibly Damaging	0.080	Benign	3.35	Benign	0.14	Tolerated	3.42	17	4	3	-0.3	-14.03	215.6	29.1	0.0	0.0	-0.7	0.1						X		Potentially Benign	The sec-butyl side chain of Ile683, located in an entangled α-α loop connecting the two α-helices (res. Ser641-Glu666 and res. Leu685-Val699), is sterically packed against His453 and Glu688. In the variant simulations, the iso-propyl side chain of Val683 has similar size and physicochemical properties as Ile630 in the WT, and thus, it is able to maintain similar interactions in the inter-helix space. Consequently, no negative structural effects are observed during the simulations due to the residue swap.
c.1480A>G	I494V (3D Viewer)		GAP	Conflicting		2	6-33438512-A-G	36	2.23e-5	-7.102	In-Between	0.112	Likely Benign	Likely Benign	0.439	Likely Benign	1.16	Ambiguous	0.0	0.71	Ambiguous	0.94	Ambiguous	1.02	Destabilizing	-0.83	Neutral	0.278	Benign	0.179	Benign	-1.30	Pathogenic	0.07	Tolerated	3.37	35	4	3	-0.3	-14.03	248.6	29.3	0.0	0.0	-1.1	0.5						X		Potentially Benign	The sec-butyl side chain of Ile494, located in an α-helix (res. Leu489-Glu519), packs against hydrophobic residues (e.g., Phe484, Leu465, Trp572, Ala493, Met468) in an inter-helix space (res. Leu489-Glu519 and res. Ala461-Phe476). In the variant simulations, the hydrophobic iso-propyl side chain of Val494, which is of a similar size and has similar physicochemical properties to Ile494 in the WT, resides similarly in the inter-helix hydrophobic space. Thus, no negative effects on the protein structure are observed.
c.1792C>G	L598V (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-10.002	Likely Pathogenic	0.578	Likely Pathogenic	Likely Benign	0.221	Likely Benign	1.89	Ambiguous	0.1	1.58	Ambiguous	1.74	Ambiguous	1.01	Destabilizing	-2.92	Deleterious	0.944	Possibly Damaging	0.786	Possibly Damaging	3.21	Benign	0.02	Affected	3.37	35	2	1	0.4	-14.03	218.4	29.6	0.0	0.0	0.8	0.0						X		Potentially Benign	The iso-butyl side chain of Leu598, located on an α helix (res. Glu582-Met603), packs hydrophobically with other hydrophobic residues in the inter-helix space (e.g., Ile602, Phe594, Ile510).In the variant simulations, Val598, which has similar size and physicochemical properties to leucine, resides in the inter-helix hydrophobic space in a similar manner to Leu598 in the WT. This causes no negative effects on the protein structure.
c.1586T>C	I529T (3D Viewer)	Likely Benign	GAP	Uncertain		1				-0.539	Likely Benign	0.336	Likely Benign	Likely Benign	0.343	Likely Benign	0.22	Likely Benign	0.2	0.16	Likely Benign	0.19	Likely Benign	0.17	Likely Benign	0.24	Neutral	0.872	Possibly Damaging	0.820	Possibly Damaging	-1.23	Pathogenic	0.55	Tolerated	3.37	35	0	-1	-5.2	-12.05	207.2	29.8	0.2	0.0	0.2	0.1						X		Potentially Benign	Ile529 is located on an α-α loop between the two α-helices (res. Gly502-Tyr518 and Ala533-Val560). In the WT simulations, the sec-butyl side chain of Ile529 faces the membrane interface and shows no specific interactions. In the variant simulations, the hydroxyl group of Thr529 forms a hydrogen bond with the carboxylate side chain of Asp527, but no negative structural changes are observed. However, due to its location near the SynGAP-membrane interface, the effect of the residue swap cannot be fully addressed using the SynGAP solvent-only simulations.
c.1393C>G	L465V (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-9.893	Likely Pathogenic	0.838	Likely Pathogenic	Ambiguous	0.276	Likely Benign	2.46	Destabilizing	0.1	2.66	Destabilizing	2.56	Destabilizing	1.21	Destabilizing	-2.98	Deleterious	0.996	Probably Damaging	0.992	Probably Damaging	2.44	Pathogenic	0.10	Tolerated	3.37	34	2	1	0.4	-14.03	204.3	30.9	0.0	0.0	-0.4	0.6						X		Potentially Benign	The iso-butyl side chain of Leu465, located in the middle of an α helix (res. Ala461–Phe476), packs with hydrophobic residues (e.g., Phe464, Met468, Tyr497, Ile494) in an inter-helix space formed with two other α helices (res. Ala461–Phe476 and res. Thr488-Gly502). In the variant simulations, the iso-propyl side chain of Val465 is equally sized and similarly hydrophobic as the original side chain of Leu465. Hence, the mutation does not exert any negative effects on the protein structure based on the variant simulations.
c.1904A>G	N635S (3D Viewer)		GAP	Conflicting		4	6-33440956-A-G	10	6.20e-6	-9.002	Likely Pathogenic	0.101	Likely Benign	Likely Benign	0.104	Likely Benign	0.80	Ambiguous	0.1	0.67	Ambiguous	0.74	Ambiguous	0.95	Ambiguous	-4.45	Deleterious	0.261	Benign	0.044	Benign	3.06	Benign	0.05	Affected	3.37	34	1	1	2.7	-27.03	196.0	30.9	0.1	0.0	-0.3	0.2				X				Uncertain	In the WT simulations, the carboxamide side chain of Asn635, located on the outer surface of an α helix (res. Glu617-Asn635), forms hydrogen bonds with Gln631 on the same α helix and with the hydroxyl side chain of Ser590 on an opposing α helix (res. Glu582-Met603).In the variant simulations, the side chain of Ser635 is shorter than asparagine and thus prefers to hydrogen bond with the carbonyl group of Gln631 on the same helix and, to a lesser extent, with Ser590 compared to Asn635 in the WT. Ser635 forms hydrogen bonds with the backbone atoms of the same helix, which may destabilize the helix, although this is not clearly evident in the simulations. The weakening of the hydrogen bond between Ser635 and Ser590 in the variant may also weaken the tertiary structure assembly between the helices.Additionally, Asn635 is at the GTPase interface. However, the implication of the residue swap on the complex formation with the GTPase cannot be investigated using solvent-only simulations.
c.1667A>G	N556S (3D Viewer)		GAP	Uncertain		1	6-33438910-A-G	3	1.86e-6	-6.576	Likely Benign	0.197	Likely Benign	Likely Benign	0.449	Likely Benign	0.52	Ambiguous	0.1	0.14	Likely Benign	0.33	Likely Benign	0.16	Likely Benign	-3.60	Deleterious	1.000	Probably Damaging	0.989	Probably Damaging	-1.22	Pathogenic	0.14	Tolerated	3.37	35	1	1	2.7	-27.03	198.8	31.0	0.0	0.0	-0.5	0.2						X		Potentially Benign	Asn556 is located on the outer surface of an α-helix (res. Ala533-Val560). The carboxamide group of Asn556 forms hydrogen bonds with nearby residues such as Lys553 and Cys552. It also forms a hydrogen bond with the backbone carbonyl group of Cys552, which weakens the α-helix integrity. In the variant simulations, the hydroxyl group of Ser556 forms a more stable hydrogen bond with the backbone carbonyl oxygen of the same helix residue, Cys552, compared to Asn556 in the WT. Serine has a slightly lower propensity to reside in an α-helix than asparagine, which may exacerbate the negative effect on the α-helix integrity. However, the residue swap does not cause negative structural effects during the simulations.
c.1625A>G	N542S (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1				-9.675	Likely Pathogenic	0.767	Likely Pathogenic	Likely Benign	0.752	Likely Pathogenic	0.98	Ambiguous	0.1	0.99	Ambiguous	0.99	Ambiguous	0.91	Ambiguous	-4.40	Deleterious	1.000	Probably Damaging	0.989	Probably Damaging	-1.36	Pathogenic	0.13	Tolerated	3.37	35	1	1	2.7	-27.03	212.5	32.1	0.0	0.0	-0.6	0.3		X						Potentially Pathogenic	Asn542 is located in an α-helix (res. Ala533-Val560) next to an α-α loop between two α-helices (res. Gly502-Tyr518 and Ala533-Val560). In the WT simulations, the carboxamide group of the Asn542 side chain forms a hydrogen bond with the backbone carbonyl group of Asn523 and packs favourably against Glu522 from the loop. In contrast, in the variant simulations, the hydroxyl group of the Ser542 side chain is unable to maintain either the hydrogen bond with Asn523 or the packing against the Glu522 side chain. Instead, the hydroxyl group of Ser542 occasionally forms a hydrogen bond with the backbone carbonyl group of Glu538.Altogether, the residue swap results in a looser helix-loop association, which is especially evident in the third replica simulation, where Asn523 moves away from its initial placement next to the α-helix. In short, based on the simulations, the residue swap weakens the GAP domain tertiary structure assembly, which in turn could negatively affect protein folding.
c.2071A>C	T691P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-13.801	Likely Pathogenic	0.905	Likely Pathogenic	Ambiguous	0.214	Likely Benign	5.04	Destabilizing	0.4	6.09	Destabilizing	5.57	Destabilizing	1.27	Destabilizing	-3.43	Deleterious	1.000	Probably Damaging	0.952	Probably Damaging	3.43	Benign	0.06	Tolerated	3.43	14	0	-1	-0.9	-3.99	188.9	33.0	0.1	0.0	-0.6	0.0	X	X						Potentially Pathogenic	The hydroxyl side chain of Thr691, located in an α-helix (res. Leu696-Leu685), can form hydrogen bonds with the backbone carbonyl and the side chain guanidinium group of Arg687. This interaction facilitates the simultaneous formation of salt bridges between Arg687 and Glu688 on the same α-helix. Additionally, Thr691 occasionally interacts with the thioether side chain of Met409 in an anti-parallel β-sheet of the C2 domain (res. Ile411-Ala399), although this interaction is not consistently maintained throughout the WT simulations. In the variant simulations, the pyrrolidine side chain of Pro691 lacks hydrogen bond donors, making a similar setup impossible. Moreover, proline lacks a free amide group necessary for hydrogen bonding with the carbonyl group of Arg687, introducing a slight bend in the α-helix and compromising its integrity.
c.1594A>C	T532P (3D Viewer)	Likely Benign	GAP	Benign		1				-2.143	Likely Benign	0.061	Likely Benign	Likely Benign	0.201	Likely Benign	-0.30	Likely Benign	0.2	0.06	Likely Benign	-0.12	Likely Benign	0.08	Likely Benign	-0.90	Neutral	0.005	Benign	0.008	Benign	-1.28	Pathogenic	0.18	Tolerated	3.37	35	0	-1	-0.9	-3.99	174.2	35.1	0.4	0.0	0.1	0.0						X		Potentially Benign	Thr532 is located on an α-α loop between the two α-helices (res. Gly502-Tyr518 and Ala533-Val560) facing the membrane. In the WT simulations, the hydroxyl group of Thr532 occasionally forms hydrogen bonds with the backbone atoms of other loop residues without any specific interaction. In the variant simulations, the Pro532 residue swap does not cause structural changes. Although hydrophilic residues seem more favorable in the loop, the pyrrolidine side chain of proline is well suited for unstructured protein regions such as loops. However, due to its location at the SynGAP-membrane interface, the effect of the residue swap cannot be fully addressed using the SynGAP solvent-only simulations.
c.1741C>T	R581W (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2				-12.855	Likely Pathogenic	0.920	Likely Pathogenic	Ambiguous	0.678	Likely Pathogenic	1.32	Ambiguous	0.1	-0.32	Likely Benign	0.50	Ambiguous	0.68	Ambiguous	-6.79	Deleterious	1.000	Probably Damaging	0.997	Probably Damaging	-1.37	Pathogenic	0.01	Affected	3.37	34	2	-3	3.6	30.03	257.8	36.0	0.1	0.1	0.1	0.3	X	X						Potentially Pathogenic	Arg581 is located on a short α-α loop between two α helices (res. Arg563-Glu578 and res. Glu582-Ser604). In the WT simulations, the guanidinium group of Arg581 forms salt bridges with the carboxylate groups of Asp583 within the same helix, as well as with Glu478 and/or Glu480 in a slightly α-helical loop (res. Glu478-Thr488) preceding another α helix (res. Ala461-Phe476).In the variant simulations, the neutral indole ring of the Trp581 side chain cannot form any of these salt bridges. Instead, it packs hydrophobically against Met477 and Ile587 without forming any direct hydrogen bonds. The tendency of the loop (res. Asp477-Thr488) to acquire an α-helical structure seems to marginally increase, potentially due to Trp581's inability to coordinate stable hydrogen bonds with the loop residues (e.g., Glu478-Arg581 salt bridge). Additionally, the residue swap could weaken the tertiary structure assembly and negatively affect the overall protein folding process.
c.835C>T	R279W (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-11.417	Likely Pathogenic	0.942	Likely Pathogenic	Ambiguous	0.485	Likely Benign	2.00	Destabilizing	0.8	1.47	Ambiguous	1.74	Ambiguous	0.80	Ambiguous	-6.29	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.88	Pathogenic	0.00	Affected	3.39	18	2	-3	3.6	30.03	270.0	38.3	0.1	0.0	0.3	0.0								Uncertain	The guanidinium group of Arg279, located at the beginning of an anti-parallel β sheet strand (res. Arg279-Leu286), can form hydrogen bond with the backbone carbonyl groups of nearby loop residues (e.g., Ser296, Ser331, and As332) and form salt bridges with the carboxylate groups of Asp330 and Asp332. In the WT simulations, Arg279 sporadically forms a salt bridge even with the carboxylate group of Glu613, loosely connecting the C2 domain and GAP domain. Meanwhile, the indole ring of the Trp279 side chain is unable to hydrogen bond with the loop residues in the variant simulations. The lack of hydrogen bond or salt bridge formation with the loop residues could be significant, as Arg279 and the loops face the polar head group region of the membrane. Thus, although Trp279 could interact with the membrane surface as a “lipid anchor,” any changes to the wider loop dynamics could still adversely affect the formation of a stable SynGAP-membrane association. However, no definite conclusions on the effect of the residue swap on the SynGAP-membrane association can be drawn from solvent-only simulations.
c.1485A>C	E495D (3D Viewer)	Likely Pathogenic	GAP	Conflicting		2				-3.574	Likely Benign	0.958	Likely Pathogenic	Likely Pathogenic	0.566	Likely Pathogenic	1.39	Ambiguous	0.1	1.03	Ambiguous	1.21	Ambiguous	0.98	Ambiguous	-2.52	Deleterious	0.998	Probably Damaging	0.989	Probably Damaging	-1.41	Pathogenic	0.17	Tolerated	3.37	35	3	2	0.0	-14.03	220.6	38.8	0.0	0.0	0.1	0.1		X		X				Uncertain	Glu495 is located in the α-helix (res. Leu489-Glu519), and its carboxylate group forms salt bridges with the neighboring Lys492 and with Arg596 on an opposing α-helix (res. Glu582-Met603) in the WT simulations. In the variant simulations, the acidic carboxylate side chain of Asp495 can also form salt bridges with both Lys492 and Arg596. However, the shorter side chain of aspartate tends to favor forming a salt bridge with the nearby Arg499 on the same α-helix instead. Asp495 might not maintain the salt bridge with Arg596 on the opposing α-helix as efficiently as Glu495 in the WT, potentially weakening the tertiary structure. Regardless, the potential negative effect is likely to be minor, with no deleterious effects observed on the protein structure during the simulations. However, due to its location at the GAP-Ras interface, the effect of the residue swap on SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations.
c.1717C>T	R573W (3D Viewer)	Likely Pathogenic	GAP	Conflicting		8				-14.078	Likely Pathogenic	0.995	Likely Pathogenic	Likely Pathogenic	0.758	Likely Pathogenic	2.37	Destabilizing	0.7	0.57	Ambiguous	1.47	Ambiguous	0.88	Ambiguous	-6.94	Deleterious	1.000	Probably Damaging	0.997	Probably Damaging	-1.48	Pathogenic	0.00	Affected	3.37	35	2	-3	3.6	30.03	257.6	39.0	0.1	0.0	0.2	0.0	X	X						Potentially Pathogenic	The guanidinium group of Arg573, located in an α-helix (res. Arg563-Glu578), forms a salt bridge with the carboxylate groups of Glu582 and/or Asp586 from a nearby α-helix (res. Glu582-Met603) in the WT simulations. Additionally, the Arg573 side chain stacks planarly with the aromatic phenol ring of Tyr665 and hydrogen bonds with the hydroxyl group of Ser668 from another α-helix (res. Ser641-Ser668). In the variant simulations, the indole ring of the Trp573 side chain is unable to maintain the same level of coordination as the positively charged Arg573 side chain. Indeed, Trp573 is seen hydrogen bonding only briefly with the carboxylate group of Glu582. Consequently, the integrity of the opposing α-helix end (res. Glu582-Met603) is weakened. Overall, the residue swap has the potential to substantially affect the tertiary structure assembly during the protein folding process.
c.970C>T	R324W (3D Viewer)	Likely Pathogenic	C2	Uncertain		1	6-33437875-C-T	2	1.24e-6	-12.906	Likely Pathogenic	0.694	Likely Pathogenic	Likely Benign	0.481	Likely Benign	1.49	Ambiguous	0.3	0.56	Ambiguous	1.03	Ambiguous	0.66	Ambiguous	-3.12	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.82	Pathogenic	0.16	Tolerated	3.39	22	2	-3	3.6	30.03	256.6	39.1	0.0	0.1	0.3	0.2		X						Potentially Pathogenic	The guanidinium group of Arg324, located at the end of an anti-parallel β sheet strand (res. Ala322-Asp330), faces outward and frequently forms a salt bridge with the carboxylate group of the Asp288 side chain, which is part of a β strand end (res. Met289-Pro298). In the variant simulations, the indole ring of the Trp324 side chain cannot maintain a similar interaction with the negatively charged carboxylate side chain of Asp288, potentially compromising the folding of the anti-parallel β sheet assembly. However, the residue swap does not appear to negatively impact the protein structure or its integrity based on the simulations.
c.1423C>T	R475W (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1	6-33438455-C-T	1	6.20e-7	-13.235	Likely Pathogenic	0.962	Likely Pathogenic	Likely Pathogenic	0.725	Likely Pathogenic	1.44	Ambiguous	0.4	-0.92	Ambiguous	0.26	Likely Benign	0.56	Ambiguous	-7.56	Deleterious	1.000	Probably Damaging	0.995	Probably Damaging	-1.45	Pathogenic	0.00	Affected	3.39	28	2	-3	3.6	30.03	266.9	39.6	0.0	0.0	0.0	0.1	X	X		X				Potentially Pathogenic	In the WT simulations, the guanidinium group of Arg475, located near the end of an α-helix (res. Ala461-Phe476), stacks with the phenyl ring of Phe476 and forms a salt bridge with Glu472. Additionally, Arg475 occasionally forms another salt bridge with the carboxylate group of Glu486 on the α-α loop connecting the two α-helices (res. Ala461-Phe476 and Leu489-Glu519) at the GAP-Ras interface. Therefore, Arg475 potentially plays a key role in positioning the loop by interacting with Glu486, which is necessary for the positioning of the “arginine finger” (Arg485) and, ultimately, for RasGTPase activation.In the variant simulations, Trp475 moves and stacks with Arg479 on the proceeding α-α loop, disrupting the terminal end of the α-helix. Lastly, the potential effect of the residue swap on the SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations.
c.700C>T	R234W (3D Viewer)	Likely Pathogenic	PH	Uncertain		1	6-33435551-C-T	3	1.86e-6	-12.625	Likely Pathogenic	0.947	Likely Pathogenic	Ambiguous	0.805	Likely Pathogenic	0.96	Ambiguous	0.3	0.69	Ambiguous	0.83	Ambiguous	0.13	Likely Benign	-5.52	Deleterious	0.997	Probably Damaging	0.803	Possibly Damaging	5.76	Benign	0.01	Affected	3.40	14	2	-3	3.6	30.03	262.8	39.6	-0.1	0.0	-0.2	0.2		X						Potentially Pathogenic	The guanidinium group of Arg234, located in a β-α loop between an anti-parallel β sheet strand (residues Gly227-Phe231) and an α helix (res. Ala236-Val250), forms a salt bridge with the carboxylate group of Glu238 in the α helix. Occasionally, it also bonds with the GAP domain residues Ser678 and Glu680. Thus, the positively charged Arg234 could contribute to the tertiary structure assembly between the PH and GAP domains. In contrast, the indole side chain of Trp234 in the variant is located on the protein surface in the variant simulations and is unable to form any interactions.
c.1306G>A	E436K (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-13.869	Likely Pathogenic	0.997	Likely Pathogenic	Likely Pathogenic	0.829	Likely Pathogenic	0.56	Ambiguous	0.1	2.86	Destabilizing	1.71	Ambiguous	0.82	Ambiguous	-3.77	Deleterious	0.994	Probably Damaging	0.951	Probably Damaging	4.71	Benign	0.02	Affected	3.37	29	0	1	-0.4	-0.94	186.8	39.8	0.0	0.0	-0.2	0.0	X	X		X				Potentially Pathogenic	The carboxylate group of Glu436, located on the α helix (res. Met414-Glu436), forms a salt bridge with the amino group of the Lys444 side chain on an opposing α helix (res. Val441-Ser457). The backbone carbonyl of Glu436 also H-bonds with the Lys444 side chain, which helps keep the ends of the two α helices tightly connected. In contrast, in the variant simulations, the salt bridge formation with Lys444 is not possible. Instead, the repelled Lys436 side chain rotates outward, causing a change in the α helix backbone H-bonding: the amide group of Lys444 H-bonds with the carbonyl of Ala433 instead of the carbonyl of Cys432.
c.775C>T	R259W (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-12.186	Likely Pathogenic	0.985	Likely Pathogenic	Likely Pathogenic	0.691	Likely Pathogenic	1.95	Ambiguous	0.8	0.51	Ambiguous	1.23	Ambiguous	0.51	Ambiguous	-7.35	Deleterious	1.000	Probably Damaging	0.993	Probably Damaging	5.76	Benign	0.00	Affected	3.39	15	2	-3	3.6	30.03	254.0	40.0	0.2	0.2	0.2	0.4	X	X					X	Potentially Pathogenic	The guanidinium group of Arg259, located at the beginning of an anti-parallel β sheet strand (res. Arg259-Arg272), forms salt bridges with the carboxylate groups of Asp684 at the end of an α helix (res. Ile683-Gln702, GAP domain) and Asp261 on the same β strand. The Arg259 side chain also frequently forms hydrogen bonds with the backbone carbonyl groups of Ser257, Asn256, and Asp255. In the variant simulations, the indole ring of the Trp259 side chain cannot form salt bridges or maintain hydrogen bonding with the carboxylate group of Asp684 or other nearby residues. Notably, the amino group of the Lys254 side chain maintains a salt bridge with Asp684 and Glu244 throughout the variant simulations, while it forms a cation-π bond with the indole ring of Trp259 in the variant. This salt bridge is not maintained in the WT simulations. Additionally, the partially or loosely α helical conformation of a lysine-containing loop (res. Lys251-Ser257), which extends to a nearby α helix (res. Met414-Asn426), could be stabilized due to the residue swap. Moreover, the bulky size of the Trp259 side chain requires nearby residues to adjust their positioning to accommodate the introduced residue, weakening the tertiary structure assembly between the C2, PH, and GAP domains. The residue swap potentially causes more severe effects during protein folding or for the SynGAP-membrane interaction than the solvent-only simulations imply.
c.1390T>G	F464V (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-12.254	Likely Pathogenic	0.994	Likely Pathogenic	Likely Pathogenic	0.592	Likely Pathogenic	3.61	Destabilizing	0.1	2.89	Destabilizing	3.25	Destabilizing	1.40	Destabilizing	-6.96	Deleterious	0.998	Probably Damaging	0.996	Probably Damaging	3.36	Benign	0.04	Affected	3.37	34	-1	-1	1.4	-48.04	210.1	40.5	-0.1	0.0	-0.9	0.3							X	Potentially Pathogenic	The phenyl ring of Phe464, located in the middle of an α helix (res. Ala461–Phe476), packs against hydrophobic residues (e.g., Met468, Leu451, Leu455, and Tyr428) in the inter-helix space formed with two other α helices (res. Asn440-Lys460 and res. Pro413-Glu436). The iso-propyl side chain of Val464 is similarly hydrophobic but considerably smaller than the original phenyl ring of Phe464. To compensate for the size difference, neighboring residues need to fill in the gap in the variant simulations.The phenolic side chain of Tyr428, located at the middle bend of an α helix (res. Glu436-Pro413), assumes a new position in the inter-helix space or rotates inward next to the third α helix (res. Asn440-Lys460) when the stable H-bond between Tyr428 and Asp467 seen in the WT simulations breaks. The residue swap also leads to the loss of the methionine-aromatic interaction between the Met468 and Phe464 side chains, which could weaken the integrity of the parent α helix (res. Ala461-Phe476). Although the simulations likely underestimate the full adverse effect of the introduced mutation during folding, the two opposing α helices (res. Ala461–Phe476 and res. Glu436-Pro413) move substantially closer to each other in the variant simulations.
c.670A>G	T224A (3D Viewer)		PH	Uncertain		3	6-33435521-A-G	2	1.24e-6	-7.379	In-Between	0.651	Likely Pathogenic	Likely Benign	0.464	Likely Benign	0.33	Likely Benign	0.1	1.05	Ambiguous	0.69	Ambiguous	0.91	Ambiguous	-2.96	Deleterious	0.243	Benign	0.079	Benign	5.57	Benign	0.57	Tolerated	3.41	13	1	0	2.5	-30.03	169.0	41.4	-0.5	1.1	-0.4	0.0	X	X						Uncertain	The introduced residue Ala224 is located on the outer surface of an anti-parallel β sheet strand (res. Cys219-Thr224). Unlike the hydroxyl group of the Thr224 side chain in the WT model, the methyl side chain of Ala224 cannot form hydrogen bonds with nearby residues Ser204, Ser226, and Gly227. Without these hydrogen-bonding interactions at the β sheet surface, the secondary structure element becomes unstable and unfolds during the variant simulations. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.742C>T	R248W (3D Viewer)	Likely Pathogenic	PH	Uncertain		1				-11.647	Likely Pathogenic	0.991	Likely Pathogenic	Likely Pathogenic	0.699	Likely Pathogenic	1.17	Ambiguous	0.3	-0.20	Likely Benign	0.49	Likely Benign	0.89	Ambiguous	-6.98	Deleterious	1.000	Probably Damaging	0.948	Probably Damaging	5.62	Benign	0.00	Affected	3.41	14	2	-3	3.6	30.03	266.4	42.3	0.0	0.0	0.3	0.1		X						Potentially Pathogenic	The guanidinium group of Arg248, located on an α helix (res. Ala236-Val250), forms two very stable salt bridges with Asp255 (from a short α helical section, res. Lys254-Asn256) and Glu244 (from a nearby loop) in the WT simulations. In the variant simulations, the indole group of Trp248 cannot form any salt bridges, which could negatively affect the tertiary structure assembly of the PH domain. Instead, in the variant simulations, the indole ring of Trp248 stacks against Pro252, which makes a turn after the α helix.
c.2014A>G	T672A (3D Viewer)	Likely Benign	GAP	Benign		1	6-33441273-A-G	3	1.86e-6	-6.524	Likely Benign	0.109	Likely Benign	Likely Benign	0.046	Likely Benign	0.51	Ambiguous	0.3	1.15	Ambiguous	0.83	Ambiguous	0.65	Ambiguous	-3.20	Deleterious	0.006	Benign	0.002	Benign	3.44	Benign	0.12	Tolerated	3.40	25	1	0	2.5	-30.03	188.5	42.5	-0.1	0.3	0.2	0.0		X						Potentially Pathogenic	The hydroxyl group of Thr672, located in an entangled α-α loop connecting the two α-helices (res. Ser641-Glu666 and res. Leu685-Val699), is involved in a highly coordinated hydrogen-bonding network between residues from two α-helices (res. Ser641-Glu666 and res. Arg563-Glu578) and from the α-α loop itself, such as Lys566, Glu666, and Asn669. In the variant simulations, Ala672 can only form a hydrogen bond with Lys566 via its backbone carbonyl group. Consequently, it cannot maintain the Lys566-Glu666 salt bridge through hydrogen bonding, leading to a significant disruption of the intricate and stable hydrogen-bond network between the loop and the helices.
c.913A>G	T305A (3D Viewer)	Likely Benign	C2	Conflicting		2	6-33437818-A-G	13	8.05e-6	-4.307	Likely Benign	0.078	Likely Benign	Likely Benign	0.144	Likely Benign	1.30	Ambiguous	0.6	1.55	Ambiguous	1.43	Ambiguous	0.77	Ambiguous	-2.10	Neutral	0.939	Possibly Damaging	0.645	Possibly Damaging	1.76	Pathogenic	0.12	Tolerated	3.40	20	1	0	2.5	-30.03	177.9	43.5	-0.2	0.1	0.4	0.0								Uncertain	The hydroxyl group of Thr305, located at the beginning of an anti-parallel β strand (res. Thr305-Asn315), hydrogen bonds with the carboxylate groups of Glu270 and Asp304 in the anti-parallel β strand and the adjacent β hairpin loop, respectively. In the variant simulations, the methyl group of the Ala305 side chain cannot hydrogen bond with either of the acidic residues, which could weaken the integrity of the tertiary structure and the β hairpin loop. Indeed, the guanidinium group of Arg299 does not acquire its central hairpin loop position due to the residue swap.β hairpins are potential nucleation sites during the initial stages of protein folding, so even minor changes in them could be significant. Due to its location near the membrane surface, the residue swap could also affect the C2 loop dynamics and SynGAP-membrane association. However, this is beyond the scope of the solvent-only simulations to unravel.
c.667A>G	T223A (3D Viewer)		PH	Uncertain		1	6-33435518-A-G	3	1.86e-6	-7.076	In-Between	0.316	Likely Benign	Likely Benign	0.574	Likely Pathogenic	0.30	Likely Benign	0.1	0.77	Ambiguous	0.54	Ambiguous	0.74	Ambiguous	-3.36	Deleterious	0.231	Benign	0.058	Benign	5.74	Benign	0.09	Tolerated	3.41	13	1	0	2.5	-30.03	186.4	44.0	0.0	0.0	0.0	0.0	X	X						Uncertain	The introduced residue Ala223 is located on the outer surface of an anti-parallel β sheet strand (res. Cys219-Thr224). Unlike the hydroxyl group of the Thr223 side chain in the WT protein, the methyl side chain of Ala223 cannot form hydrogen bonds with nearby residues Thr228 and Lys207. Without these hydrogen-bonding interactions at the β sheet surface, the secondary structure element becomes unstable and partially unfolds in the variant simulations. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.1322T>C	V441A (3D Viewer)		GAP	Conflicting		2	6-33438227-T-C	3	1.86e-6	-9.439	Likely Pathogenic	0.359	Ambiguous	Likely Benign	0.053	Likely Benign	-0.14	Likely Benign	0.0	0.33	Likely Benign	0.10	Likely Benign	0.95	Ambiguous	-2.92	Deleterious	0.513	Possibly Damaging	0.214	Benign	3.44	Benign	0.93	Tolerated	3.37	29	0	0	-2.4	-28.05	195.0	44.6	0.0	0.1	0.5	0.0				X		X		Uncertain	The iso-propyl side chain of Val441, located on the outer surface of an α helix (res. Asn440-Thr458), does not interact with other residues in the WT simulations. In the variant simulations, the methyl side chain of Ala441 is similarly hydrophobic and does not form any interactions on the outer helix surface. Although the residue swap does not negatively affect the protein structure based on the simulations, it is noteworthy that the residue faces the RasGTPase interface. Thus, the effect of the residue swap on the SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations.
c.1285C>T	R429W (3D Viewer)		GAP	Conflicting		5	6-33438190-C-T	65	4.03e-5	-10.666	Likely Pathogenic	0.500	Ambiguous	Likely Benign	0.282	Likely Benign	0.31	Likely Benign	0.1	-0.13	Likely Benign	0.09	Likely Benign	0.52	Ambiguous	-3.19	Deleterious	1.000	Probably Damaging	0.990	Probably Damaging	3.41	Benign	0.03	Affected	3.38	25	2	-3	3.6	30.03	252.3	45.5	0.0	0.0	0.2	0.1		X						Potentially Pathogenic	The guanidinium group of Arg429, located in an α helix (res. Met414-Glu436), either forms a salt bridge with the carboxylate group of an acidic residue (Asp474, Asp467) or a H-bond with the hydroxyl group of Ser471 in an opposing α helix (res. Ala461-Phe476). In the variant simulations, the indole ring of the Trp429 side chain cannot form ionic interactions with the acidic residues. Although it forms a H-bond with Ser471, the bonding is not as strong as that of arginine. The residue swap could affect the tertiary structure assembly during folding; however, no large-scale negative effects were seen during the simulations.
c.1529T>G	I510S (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-11.661	Likely Pathogenic	0.955	Likely Pathogenic	Ambiguous	0.926	Likely Pathogenic	4.00	Destabilizing	0.1	3.78	Destabilizing	3.89	Destabilizing	2.34	Destabilizing	-4.63	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	-1.44	Pathogenic	0.00	Affected	3.37	35	-1	-2	-5.3	-26.08	201.4	45.9	-0.4	0.2	0.0	0.3							X	Potentially Pathogenic	Ile510 is located in the middle of an α-helix (res. Gly502-Tyr518) within the inter-helix space of three helices (res. Gly502-Tyr518, Ala533-Val560, and res. Glu582-Met603). In the WT simulations, the sec-butyl side chain of Ile510 hydrophobically packs with other residues in the inter-helix space (e.g., Leu506, Leu610, Ile514, Ile602, Leu598). In the variant simulations, the hydroxyl group of Ser510 forms a hydrogen bond with the backbone atoms of Leu506 and Gly511 in the same α-helix, which could further weaken the α-helix integrity. This α-helix already shows weakness in the WT simulations due to Gly511. Although the simulations do not show large-scale effects, the residue swap could have a substantial impact due to the fundamental role of hydrophobic packing during protein folding.
c.1409T>C	M470T (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-8.104	Likely Pathogenic	0.976	Likely Pathogenic	Likely Pathogenic	0.763	Likely Pathogenic	3.19	Destabilizing	0.1	2.68	Destabilizing	2.94	Destabilizing	1.49	Destabilizing	-5.30	Deleterious	0.996	Probably Damaging	0.985	Probably Damaging	-1.08	Pathogenic	0.24	Tolerated	3.37	34	-1	-1	-2.6	-30.09	213.8	46.5	0.0	0.0	-0.2	0.2		X					X	Potentially Pathogenic	The thioether group of Met470, located in the middle of an α helix (res. Ala461–Phe476), interacts with hydrophobic residues in the inter-helix space (e.g., Val473, Leu558, Cys576, Trp572) formed by two other α helices (res. Ser604–Arg581, res. Pro562–Arg579). In the WT simulations, the Met470 side chain also packs against the positively charged guanidinium groups of Arg575, Arg429, and Arg579, which form salt bridges with the negatively charged carboxylate groups of the Asp474 and Asp467 side chains at the protein surface. In the variant simulations, the hydroxyl group of the Thr470 side chain forms an H-bond with the backbone carbonyl group of Ser466 in the α helix, potentially lowering its structural integrity. Importantly, the hydroxyl group of Thr470 also forms an H-bond with the guanidinium group of Arg575, which helps it form a more permanent salt bridge with Asp467.
c.1403T>C	M468T (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33438435-T-C	1	6.20e-7	-12.399	Likely Pathogenic	0.862	Likely Pathogenic	Ambiguous	0.801	Likely Pathogenic	3.47	Destabilizing	0.1	3.10	Destabilizing	3.29	Destabilizing	1.84	Destabilizing	-3.85	Deleterious	0.994	Probably Damaging	0.985	Probably Damaging	-1.31	Pathogenic	0.01	Affected	3.37	31	-1	-1	-2.6	-30.09	214.6	47.1	0.0	0.0	0.1	0.0							X	Potentially Pathogenic	The thioether group of Met468, located in the middle of an α helix (res. Ala461–Phe476), interacts with hydrophobic residues (e.g., Phe464, Leu465, Leu489) in an inter-helix space formed by two other α helices (res. Ala461–Phe476, res. Thr488–Gly502). In the variant simulations, the hydrophilic side chain of Thr468 does not pack favorably in the hydrophobic niche, and the methionine-aromatic stacking is lost. Although the hydroxyl group of Thr468 forms an H-bond with the backbone carbonyl group of Phe464, the integrity of the α helix is not affected in the simulations. No large-scale structural changes are observed during the variant simulations; however, due to the importance of hydrophobic packing, the effects could be more pronounced during protein folding.
c.2147G>A	R716Q (3D Viewer)		GAP	Conflicting		2	6-33441612-G-A	4	2.48e-6	-8.338	Likely Pathogenic	0.308	Likely Benign	Likely Benign	0.210	Likely Benign	-0.01	Likely Benign	0.0	0.47	Likely Benign	0.23	Likely Benign	0.58	Ambiguous	-3.14	Deleterious	1.000	Probably Damaging	0.990	Probably Damaging	3.35	Benign	0.02	Affected	3.50	9	1	1	1.0	-28.06	250.0	48.9	0.0	0.0	-0.5	0.0						X		Uncertain	The guanidinium group of Arg716, located on the outer surface of an α-helix (res. Leu714-Arg726), forms a salt bridge with the carboxylate group of Asp720. In the variant simulations, the carboxamide group of Gln716 also forms a hydrogen bond with the carboxylate group of Asp720, although this bond is weaker than the Arg716 salt bridge in the WT. Overall, no adverse effects on the protein structure are observed in the simulations. However, because the model ends abruptly at the C-terminus, no definite conclusions can be drawn based on the simulations.
c.2116G>A	E706K (3D Viewer)		GAP	Uncertain		1				-10.519	Likely Pathogenic	0.833	Likely Pathogenic	Ambiguous	0.080	Likely Benign	1.17	Ambiguous	0.1	0.51	Ambiguous	0.84	Ambiguous	0.08	Likely Benign	-1.51	Neutral	0.345	Benign	0.028	Benign	4.15	Benign	0.52	Tolerated	3.47	10	0	1	-0.4	-0.94	187.1	49.2	0.0	0.0	0.4	0.1						X		Uncertain	The carboxylate side chain of Glu706, located at the end and outer surface of an α-helix (res. Thr704-Gly712), forms a salt bridge with Lys710 and a hydrogen bond with its own backbone amino group at the helix end in the WT simulations. Although Lys706 is unable to make these transient interactions in the variant simulations, there is no apparent negative effect on the protein structure due to the residue swap. However, because the model ends abruptly at the C-terminus, no definite conclusions can be drawn based on the simulations.
c.2162T>G	I721S (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.032	Likely Pathogenic	0.996	Likely Pathogenic	Likely Pathogenic	0.466	Likely Benign	3.91	Destabilizing	0.1	3.96	Destabilizing	3.94	Destabilizing	2.28	Destabilizing	-5.26	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.21	Pathogenic	0.00	Affected	3.50	9	-1	-2	-5.3	-26.08	203.3	49.3	-0.1	0.0	-1.1	0.0							X	Uncertain	The sec-butyl side chain of Ile721, located on an α-helix (res. Leu714-Arg726), engages in hydrophobic packing with other residues in the hydrophobic inter-helix space, such as Phe420, Tyr417, His693, and Leu717. In the variant simulations, the hydroxyl side chain of Ser721 forms hydrogen bonds with nearby residues, such as Leu717 and His693. Although no major structural changes are observed during the variant simulations, the hydrophilic residue Ser721 could disrupt the hydrophobic packing during folding. However, because the model ends abruptly at the C-terminus, no definite conclusions can be drawn based on the simulations.
c.1768A>G	S590G (3D Viewer)	Likely Pathogenic	GAP	Conflicting		2	6-33440820-A-G	14	8.67e-6	-14.277	Likely Pathogenic	0.574	Likely Pathogenic	Likely Benign	0.379	Likely Benign	0.67	Ambiguous	0.1	1.28	Ambiguous	0.98	Ambiguous	0.71	Ambiguous	-3.92	Deleterious	1.000	Probably Damaging	0.922	Probably Damaging	3.42	Benign	0.06	Tolerated	3.37	35	1	0	0.4	-30.03	186.7	49.4	0.0	0.0	0.1	0.0		X						Potentially Pathogenic	In the WT simulations, the hydroxyl group of Ser590, located on an α helix (res. Glu582-Met603), forms hydrogen bonds with the backbone carbonyl of Ala634 and/or the carboxamide group of the Asn635 side chain at the end of the opposing α helix (res. Thr619-Ala634).The residue swap could weaken the integrity of the α helix, as glycine is known as an “α helix breaker.” However, no discernible difference was observed between the WT and variant simulations in this regard. Importantly, Gly590 cannot form hydrogen bonds with the opposing helix in the same way that serine can, which could weaken the tertiary structure assembly between the two helices.
c.1718G>A	R573Q (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-9.900	Likely Pathogenic	0.923	Likely Pathogenic	Ambiguous	0.733	Likely Pathogenic	2.28	Destabilizing	0.8	1.94	Ambiguous	2.11	Destabilizing	1.08	Destabilizing	-3.16	Deleterious	1.000	Probably Damaging	0.995	Probably Damaging	-1.31	Pathogenic	0.12	Tolerated	3.37	35	1	1	1.0	-28.06	230.1	49.9	0.0	0.0	-0.6	0.0	X	X						Potentially Pathogenic	The guanidinium group of Arg573, located in an α-helix (res. Arg563-Glu578), forms a salt bridge with the carboxylate groups of Glu582 and/or Asp586 from a nearby α-helix (res. Glu582-Met603) in the WT simulations. Additionally, the Arg573 side chain stacks planarly with the aromatic phenol ring of Tyr665 and hydrogen bonds with the hydroxyl group of Ser668 from another α-helix (res. Ser641-Ser668). In the variant simulations, although the carboxamide group of the Gln573 side chain can hydrogen bond with the carboxylate group of Glu582 or the hydroxyl group of Ser668, these interactions are not as coordinated, stable, or strong as those of the positively charged Arg573. Consequently, the integrity of the opposing α-helix end (res. Glu582-Met603) is weakened. Overall, the residue swap has the potential to substantially affect the tertiary structure assembly during the protein folding process.
c.1991T>C	L664S (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33441250-T-C	1	6.20e-7	-16.498	Likely Pathogenic	0.997	Likely Pathogenic	Likely Pathogenic	0.543	Likely Pathogenic	3.75	Destabilizing	0.2	3.63	Destabilizing	3.69	Destabilizing	2.77	Destabilizing	-5.99	Deleterious	1.000	Probably Damaging	0.996	Probably Damaging	2.85	Benign	0.00	Affected	3.38	28	-3	-2	-4.6	-26.08	215.5	50.1	0.0	0.0	-0.2	0.2						X		Potentially Benign	The iso-butyl side chain of L664, located on an α-helix (res. Ser641-Glu666), hydrophobically interacts with residues in the inter-helix space between three helices (res. Glu617-Asn635, res. Glu582-Met603, and res. Ser641-Glu666), such as Ile589, Phe663, and Met660. In the variant simulations, the hydroxyl group of Ser664 forms hydrogen bonds with the backbone carbonyl oxygen of another helix residue, such as Met660 or Gln661. This interaction is known to destabilize hydrogen bonding in the α-helix, but this effect was not observed in the simulations. Additionally, Ser664 occasionally forms hydrogen bonds with the carboxylate group of Asp586 on another α-helix (res. Glu582-Met603), which could minimally influence the tertiary structure assembly. Despite these interactions, no major negative effects on the protein structure were observed during the simulations.
c.662A>T	E221V (3D Viewer)	Likely Pathogenic	PH	Likely Pathogenic		1				-14.954	Likely Pathogenic	0.987	Likely Pathogenic	Likely Pathogenic	0.875	Likely Pathogenic	-0.66	Ambiguous	0.2	-0.89	Ambiguous	-0.78	Ambiguous	0.49	Likely Benign	-5.54	Deleterious	0.596	Possibly Damaging	0.203	Benign	5.86	Benign	0.00	Affected	3.41	13	-2	-2	7.7	-29.98	234.5	50.6	0.0	0.0	-0.4	0.2		X						Uncertain	The introduced residue Val221 is located on the outer surface of an anti-parallel β sheet strand (res. Cys219-Thr224). Unlike the carboxylate group of Glu221, Val221 cannot form hydrogen bonds with Thr223 or a salt bridge with the amino group of the Lys207 side chain. Despite this, the WT simulations containing Glu221 do not show significant differences compared to the variant simulations. However, since the model ends abruptly at the N-terminus, no definite conclusions can be drawn from the simulations.
c.865A>G	M289V (3D Viewer)	Likely Benign	C2	Benign		1				-4.239	Likely Benign	0.117	Likely Benign	Likely Benign	0.150	Likely Benign	1.09	Ambiguous	0.1	-0.27	Likely Benign	0.41	Likely Benign	0.24	Likely Benign	-0.36	Neutral	0.136	Benign	0.054	Benign	1.80	Pathogenic	1.00	Tolerated	3.38	23	2	1	2.3	-32.06	204.2	51.0	0.0	0.0	0.2	0.0						X		Potentially Benign	The hydrophobic residue Met289, located in a β hairpin linking two anti-parallel β sheet strands (res. Met289-Arg299, res. Arg272-Leu286), is swapped for another hydrophobic residue, valine. In the variant simulations, the branched hydrocarbon side chain of Val289 packs against the phenol group of the Tyr291 side chain but is unable to form methionine-aromatic interactions. β hairpins are potential nucleation sites during the initial stages of protein folding, so even minor changes in them could be significant. However, based on the simulations, the residue swap does not cause adverse effects on the structure.
c.1456G>A	E486K (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-14.545	Likely Pathogenic	0.988	Likely Pathogenic	Likely Pathogenic	0.435	Likely Benign	0.06	Likely Benign	0.1	0.37	Likely Benign	0.22	Likely Benign	0.41	Likely Benign	-3.58	Deleterious	1.000	Probably Damaging	0.988	Probably Damaging	3.40	Benign	0.12	Tolerated	3.37	35	0	1	-0.4	-0.94	206.8	52.1	-0.3	0.1	0.2	0.0	X			X				Uncertain	Glu486 is located in an α-α loop connecting the two α-helices (res. Ala461-Phe476 and Leu489-Glu519) at the GAP-Ras interface. It is adjacent to the arginine finger (Arg485) and is expected to closely interact with Ras. The residue swap could affect complex formation with the GTPase and its activation. In the WT simulations, the carboxylate group of Glu486 forms salt bridges with Arg485 and Arg475 on the preceding α-helix (res. Ala461-Phe476). In the variant simulations, Lys486 does not form any specific interactions. Although the amino group of the Lys486 side chain cannot form these salt bridges, no negative effects on the protein structure are observed. Nevertheless, the potential role of Glu486 in SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations, and no definite conclusions can be drawn.
c.1424G>A	R475Q (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33438456-G-A	5	3.10e-6	-12.087	Likely Pathogenic	0.721	Likely Pathogenic	Likely Benign	0.632	Likely Pathogenic	0.71	Ambiguous	0.1	0.12	Likely Benign	0.42	Likely Benign	0.82	Ambiguous	-3.65	Deleterious	1.000	Probably Damaging	0.991	Probably Damaging	-1.32	Pathogenic	0.01	Affected	3.39	28	1	1	1.0	-28.06	253.6	52.7	0.0	0.0	-0.8	0.0	X	X		X				Potentially Pathogenic	In the WT simulations, the guanidinium group of Arg475, located near the end of an α-helix (res. Ala461-Phe476), stacks with the phenyl ring of Phe476 and forms a salt bridge with Glu472. Additionally, Arg475 occasionally forms another salt bridge with the carboxylate group of Glu486 on the α-α loop connecting the two α-helices (res. Ala461-Phe476 and Leu489-Glu519) at the GAP-Ras interface. Therefore, Arg475 potentially plays a key role in positioning the loop by interacting with Glu486, which is necessary for the positioning of the “arginine finger” (Arg485) and, ultimately, for RasGTPase activation. In the variant simulations, Asn475 forms a hydrogen bond with Arg479 on the proceeding α-α loop. The absence of Phe476/Arg475 stacking and the Arg475-Glu472 salt bridge weakens the integrity of the terminal end of the α-helix during the variant simulations. Lastly, the potential effect of the residue swap on the SynGAP-Ras complex formation or GTPase activation cannot be fully addressed using the SynGAP solvent-only simulations.
c.815G>A	R272Q (3D Viewer)		C2	Uncertain		2	6-33437720-G-A	14	8.67e-6	-9.559	Likely Pathogenic	0.286	Likely Benign	Likely Benign	0.321	Likely Benign	0.73	Ambiguous	0.1	0.15	Likely Benign	0.44	Likely Benign	1.00	Destabilizing	-1.81	Neutral	0.999	Probably Damaging	0.994	Probably Damaging	1.88	Pathogenic	0.03	Affected	3.38	19	1	1	1.0	-28.06	255.7	52.9	0.0	0.0	-0.2	0.1				X				Uncertain	The guanidinium group of Arg272, located at the end of an anti-parallel β sheet strand (res. Arg259-Arg272), is stably maintained in an upright and outward position via stacking with the indole ring of the Trp362 side chain in another β strand (res. Thr359-Pro364). In the WT simulations, Arg272 forms hydrogen bonds with the glycine-rich Ω loop residues (res. Val365-Pro398, e.g., Gly380) and creates a salt bridge with the carboxylate group of the Asp304 side chain.In the variant simulations, the carboxamide group of the Gln272 side chain does not stack with the indole ring of Trp362 as stably as the guanidinium group of Arg272 in the WT. Consequently, the Gln272 side chain is freer to interact with the loop residues than Arg272, potentially negatively affecting the dynamic SynGAP-membrane association. Additionally, Arg272 faces the RasGTPase interface, so the residue swap could impact the SynGAP-Ras complex formation and GTPase activation.
c.1742G>A	R581Q (3D Viewer)	Likely Pathogenic	GAP	Benign		1	6-33440794-G-A	8	4.96e-6	-7.584	In-Between	0.673	Likely Pathogenic	Likely Benign	0.481	Likely Benign	1.31	Ambiguous	0.1	-0.42	Likely Benign	0.45	Likely Benign	0.88	Ambiguous	-2.77	Deleterious	1.000	Probably Damaging	0.995	Probably Damaging	-1.21	Pathogenic	0.11	Tolerated	3.37	34	1	1	1.0	-28.06	239.6	53.5	-0.2	0.2	-0.4	0.1		X						Potentially Pathogenic	Arg581 is located on a short α-α loop between two α helices (res. Arg563-Glu578 and res. Glu582-Ser604). In the WT simulations, the guanidinium group of Arg581 forms salt bridges with the carboxylate groups of Asp583 within the same helix, as well as with Glu478 and/or Glu480 on a slightly α-helical loop (res. Glu478-Thr488) preceding another α helix (res. Ala461-Phe476).In the variant simulations, the neutral carboxamide group of the Gln581 side chain cannot form any of these salt bridges. Instead, it packs hydrophobically against Met477 and Ile587 or forms hydrogen bonds sporadically with nearby residues (e.g., Asp583, Arg587). Thus, although no drastic changes are observed in the variant simulations, the residue swap could weaken the tertiary structure assembly.
c.1862G>A	R621Q (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33440914-G-A	19	1.18e-5	-14.682	Likely Pathogenic	0.910	Likely Pathogenic	Ambiguous	0.621	Likely Pathogenic	0.81	Ambiguous	0.1	1.13	Ambiguous	0.97	Ambiguous	1.35	Destabilizing	-3.98	Deleterious	1.000	Probably Damaging	0.997	Probably Damaging	2.82	Benign	0.01	Affected	3.37	35	1	1	1.0	-28.06	243.7	54.3	0.0	0.0	-0.4	0.2		X		X				Potentially Pathogenic	The guanidinium group of Arg621, located in an α helix (res. Glu617-Asn635), forms a salt bridge with Glu525 in a nearby loop and stacks with Leu635. In the variant simulations, the carboxamide side chain of Gln621, which can act as both a hydrogen bond acceptor and donor, also stacks with Leu635 but can only sporadically hydrogen bond with Glu525.Accordingly, the residue swap could affect the tertiary structure integrity by disrupting the salt bridge formation. Additionally, due to its location at the GAP-Ras interface, the residue swap could impact the complex formation with the GTPase, but this cannot be investigated using solvent-only simulations.
c.1259T>C	F420S (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-13.231	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.544	Likely Pathogenic	5.34	Destabilizing	0.1	5.73	Destabilizing	5.54	Destabilizing	2.14	Destabilizing	-7.43	Deleterious	0.998	Probably Damaging	0.938	Probably Damaging	3.09	Benign	0.00	Affected	3.37	29	-3	-2	-3.6	-60.10	213.3	57.8	0.0	0.0	-0.4	0.1							X	Potentially Pathogenic	In the WT, the phenyl ring of the Phe420 side chain, located on an α helix (res. Met414-Glu436), packs against hydrophobic residues in the interhelix area of the GAP domain (e.g., Leu689, Leu714, Leu717, Leu718). Although no large-scale adverse effects are seen in the variant simulations, the polar hydroxyl group of Ser420 is not suitable for the hydrophobic inter-helix space. Thus, the residue swap could affect protein folding. In theory, the introduced hydroxyl group could also lower the α helix integrity by H-bonding with the backbone atoms of neighboring residues in the same α helix. However, no such effect is seen in the variant simulations.
c.928G>A	E310K (3D Viewer)	Likely Pathogenic	C2	Conflicting		4				-14.601	Likely Pathogenic	0.997	Likely Pathogenic	Likely Pathogenic	0.764	Likely Pathogenic	1.97	Ambiguous	1.2	3.66	Destabilizing	2.82	Destabilizing	1.02	Destabilizing	-3.68	Deleterious	1.000	Probably Damaging	0.995	Probably Damaging	1.19	Pathogenic	0.01	Affected	3.38	19	0	1	-0.4	-0.94	213.4	58.0	0.1	0.0	0.2	0.1		X						Potentially Pathogenic	The carboxylate group of Glu310, located in an anti-parallel β sheet strand (res. Thr305-Asn315), is ideally positioned to interact with the side chain hydroxyl and backbone amide groups of Thr295 on a twisted anti-parallel β strand (res. Met289-Arg299). Because the carboxylate group can also interact with the GAP domain residues (e.g., Gln612, Tyr614), Glu310 plays a key role in maintaining the tertiary assembly between the C2 and GAP domains. In the variant simulations, the amino group of the Lys310 side chain hydrogen bonds with the GAP domain residues and forms a salt bridge with Glu613. Although no apparent negative effects are seen due to the residue swap, it is possible that the loss of hydrogen bonding with the hydroxyl group of the Thr295 side chain causes problems during folding, potentially compromising the twisting of the β sheet.
c.1490A>G	Y497C (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-11.872	Likely Pathogenic	0.948	Likely Pathogenic	Ambiguous	0.806	Likely Pathogenic	3.88	Destabilizing	0.1	4.76	Destabilizing	4.32	Destabilizing	1.40	Destabilizing	-8.82	Deleterious	1.000	Probably Damaging	0.995	Probably Damaging	-1.65	Pathogenic	0.03	Affected	3.37	35	0	-2	3.8	-60.04	209.9	59.1	-0.1	0.0	-0.3	0.1		X					X	Potentially Pathogenic	Tyr497 is located in the α-helix (res. Leu489-Glu519) within the inter-helix space of four α-helices (res. Leu489-Ile501, res. Val441-Ser457, res. Arg563-Glu578, res. Ala461-Val473). In the WT simulations, the phenol ring of Tyr497 hydrophobically packs with other residues in the inter-helix space (e.g., Leu465, Leu565, Val568). The hydroxyl group of Tyr497 also alternately forms hydrogen bonds with the carboxylate side chain of Gln456 and the backbone carbonyl of Glu564. Thus, Tyr497 plays a role in the folding and maintenance of the tertiary structure assembly between these four helices.In the variant simulations, the comparatively smaller residue, Cys497, cannot maintain any of the interactions seen with Tyr497 in the WT. Although no severe deleterious consequences are observed in the simulations, the structural effects could be more pronounced during actual protein folding. Indeed, the tertiary structure is seen to slightly break apart in the variant simulations.
c.1286G>A	R429Q (3D Viewer)	Likely Benign	GAP	Uncertain		2	6-33438191-G-A	10	6.20e-6	-8.227	Likely Pathogenic	0.143	Likely Benign	Likely Benign	0.156	Likely Benign	0.45	Likely Benign	0.1	0.36	Likely Benign	0.41	Likely Benign	0.98	Ambiguous	-1.25	Neutral	1.000	Probably Damaging	0.979	Probably Damaging	3.47	Benign	0.58	Tolerated	3.38	25	1	1	1.0	-28.06	235.8	59.5	0.0	0.0	-0.3	0.4		X						Potentially Pathogenic	The guanidinium group of the Arg429 side chain, located in an α helix (res. Met414-Glu436), either forms a salt bridge with the carboxylate group of an acidic residue (Asp474, Asp467) or an H-bond with the hydroxyl group of Ser471 in an opposing α helix (res. Ala461-Phe476). In the variant simulations, Gln429 cannot form ionic interactions with the acidic residues; however, the carboxamide group can form multiple H-bonds. The H-bonding coordination of the Asn429 side chain varied between the replica simulations. In one simulation, three H-bonds were formed simultaneously with the Asp467 side chain, the backbone carbonyl group of Asn426, and the amide group of Met430 at the end of the same α helix. The residue swap could affect the tertiary structure assembly during folding due to weaker bond formation, but no large-scale negative effects were seen during the simulations.
c.924G>C	W308C (3D Viewer)	Likely Pathogenic	C2	Pathogenic/Likely path.		2				-12.791	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.738	Likely Pathogenic	5.56	Destabilizing	0.3	4.38	Destabilizing	4.97	Destabilizing	1.26	Destabilizing	-11.95	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	0.48	Pathogenic	0.00	Affected	3.38	19	-8	-2	3.4	-83.07	230.8	60.5	-0.3	0.1	-0.4	0.4							X	Potentially Pathogenic	The indole ring of Trp308, located in an anti-parallel β sheet strand (res. Thr305-Asn315), packs against multiple hydrophobic residues (e.g., Ile268, Val306, Cys282). The indole group of Trp308 also hydrogen bonds with the backbone atoms of the C2 domain residues forming the anti-parallel β sheet (e.g., Tyr280, Thr294). The introduced Cys308 is smaller than the tryptophan it replaced. The thiol group of the Cys308 side chain is well-suited for the inner hydrophobic part of the C2 domain. Although the negative effects are essentially missing from the simulations, the side chain size difference between the residues is likely to disrupt the hydrophobic packing during folding. At a minimum, the residue swap could affect the C2 domain stability and membrane association.
c.1718G>T	R573L (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-13.120	Likely Pathogenic	0.993	Likely Pathogenic	Likely Pathogenic	0.833	Likely Pathogenic	1.30	Ambiguous	0.6	1.11	Ambiguous	1.21	Ambiguous	0.80	Ambiguous	-5.74	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.41	Pathogenic	0.01	Affected	3.37	35	-3	-2	8.3	-43.03	237.4	60.7	0.0	0.0	-0.7	0.3	X	X						Potentially Pathogenic	The guanidinium group of Arg573, located in an α-helix (res. Arg563-Glu578), forms a salt bridge with the carboxylate groups of Glu582 and/or Asp586 from a nearby α-helix (res. Glu582-Met603) in the WT simulations. Additionally, the Arg573 side chain stacks planarly with the aromatic phenol ring of Tyr665 and hydrogen bonds with the hydroxyl group of Ser668 from another α-helix (res. Ser641-Ser668). In the variant simulations, the aliphatic iso-butyl group of the Leu573 side chain fails to establish any of these interactions, which, in turn, lowers the integrity of the opposing α-helix end (res. Glu582-Met603). Overall, the residue swap has the potential to substantially affect the tertiary structure assembly during the protein folding process.	10.1016/j.ajhg.2020.11.011
c.1652T>C	L551P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-14.620	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.953	Likely Pathogenic	6.66	Destabilizing	0.1	6.58	Destabilizing	6.62	Destabilizing	2.66	Destabilizing	-4.70	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.60	Pathogenic	0.01	Affected	3.37	35	-3	-3	-5.4	-16.04	208.6	60.9	0.1	0.0	-0.3	0.0	X							Potentially Pathogenic	L551 is located on an α-helix (res. Ala533-Val560). The iso-butyl side chain of Leu551 hydrophobically packs with nearby hydrophobic residues such as Cys547, Phe652, Leu633, and Ile630 in the inter-helix space. In the variant simulations, the pyrrolidine side chain of Pro551 is not as optimal as leucine for hydrophobic packing with the nearby residues. Moreover, Pro551 lacks the amide group, and thus, it cannot form a hydrogen bond with the backbone carbonyl group of Cys547, which disrupts the continuity of the secondary structure element.
c.1466T>C	L489P (3D Viewer)	Likely Pathogenic	GAP	Conflicting		2				-13.520	Likely Pathogenic	0.997	Likely Pathogenic	Likely Pathogenic	0.939	Likely Pathogenic	2.50	Destabilizing	0.1	4.69	Destabilizing	3.60	Destabilizing	1.73	Destabilizing	-6.74	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.56	Pathogenic	0.00	Affected	3.37	35	-3	-3	-5.4	-16.04	209.9	61.9	0.1	0.0	0.6	0.1		X						Potentially Pathogenic	The iso-butyl side chain of Leu489, located in the α-helix (res. Leu489-Glu519) within an inter-helix space of four helices (res. Ala461-Phe476, res. Val441-Ser457, and res. Met414-Glu436), packs with hydrophobic residues (e.g., Cys432, Ala448, Lys444, Ala493, Val447, Met468). In the variant simulations, Pro489 is located near the beginning of the α-helix, so the residue swap with Leu489 does not affect the continuity of the secondary structure element. However, the side chain of proline is not as optimal as that of leucine for maintaining hydrophobic packing with nearby residues (e.g., Ala448, Lys444). Additionally, the consistently maintained hydrogen bond interaction between the backbone amide group of Leu489 and the carbonyl of Glu436 is lost due to the residue swap, potentially affecting the tertiary structure integrity.
c.1025A>G	Y342C (3D Viewer)	Likely Pathogenic	C2	Benign/Likely benign		2	6-33437930-A-G	21	1.30e-5	-7.596	In-Between	0.682	Likely Pathogenic	Likely Benign	0.404	Likely Benign	2.48	Destabilizing	0.1	2.73	Destabilizing	2.61	Destabilizing	0.92	Ambiguous	-6.67	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.72	Pathogenic	0.02	Affected	3.37	25	0	-2	3.8	-60.04	242.4	62.8	0.1	0.0	-0.1	0.2								Potentially Pathogenic	The phenol ring of Tyr342, located at the end of an anti-parallel β sheet strand (res. Gly341-Pro349), faces outward in the C2 domain. This phenol ring contributes to a triple tyrosine stack (Tyr342, Tyr328, and Tyr281) that links together three anti-parallel β sheet strands. Additionally, it shields Gly344 from the solvent, reducing its exposure and providing stability for the β-sandwich. This motif also contributes to a twist formation in the β sheet.In the variant simulations, the Cys342 side chain cannot participate in the stack formation. Instead, its thiol group forms a hydrogen bond with the backbone carbonyl group of Leu327. Although these changes in surface interactions could weaken the characteristic twist that strengthens the β sheet fold, no major structural effects are observed in the variant simulations. The residue swap could also affect the SynGAP-membrane association; however, this phenomenon cannot be addressed using solvent-only simulations. Notably, the thiol group of cysteine is not a particularly strong hydrogen-bonding partner, which could mitigate the negative effects of the residue swap.
c.1292T>C	L431P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-14.222	Likely Pathogenic	0.996	Likely Pathogenic	Likely Pathogenic	0.659	Likely Pathogenic	6.78	Destabilizing	0.3	11.59	Destabilizing	9.19	Destabilizing	2.29	Destabilizing	-6.39	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	2.91	Benign	0.05	Affected	3.37	29	-3	-3	-5.4	-16.04	222.4	62.8	0.1	0.0	0.1	0.0	X							Potentially Pathogenic	The iso-butyl side chain of Leu431, located in an α helix (res. Met414-Glu436), packs against other hydrophobic residues in an interhelix space (e.g., Val434, Leu435, Leu696, Leu711) in the WT simulations. While the backbone amide group of Leu431 forms an H-bond with the carbonyl group of His427, the cyclic five-membered pyrrolidine ring of Pro431, lacking the necessary amide group, cannot do the same. Thus, although the cyclic five-membered pyrrolidine ring of Pro431 packs almost as favorably as the side chain of Leu431 in the hydrophobic niche, the residue swap causes the α helix to partially unfold in the variant simulations.
c.2075T>C	L692P (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-16.447	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.668	Likely Pathogenic	9.19	Destabilizing	0.1	13.20	Destabilizing	11.20	Destabilizing	1.69	Destabilizing	-6.98	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	3.06	Benign	0.00	Affected	3.42	17	-3	-3	-5.4	-16.04	186.2	62.8	-0.2	0.1	-0.7	0.3	X							Potentially Pathogenic	The isobutyl side chain of Leu692, located in the middle of an α-helix (res. Leu685-Gln702), engages in hydrophobic packing with nearby residues (e.g., Leu441, Leu431, Leu696) in the inter-helix space. Prolines lack a free amide group necessary for hydrogen bonding with the carbonyl group of Glu688 in the same manner as Leu692 in the WT. Consequently, the residue swap with proline disrupts the continuity of the secondary structure element in the variant simulations. Additionally, the side chain of Pro692 is not as optimal as Leu692 for hydrophobic packing in the inter-helix space.
c.1787G>T	R596L (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-13.197	Likely Pathogenic	0.992	Likely Pathogenic	Likely Pathogenic	0.756	Likely Pathogenic	1.51	Ambiguous	0.3	-0.58	Ambiguous	0.47	Likely Benign	-0.02	Likely Benign	-6.97	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.45	Pathogenic	0.00	Affected	3.37	35	-3	-2	8.3	-43.03	234.2	63.4	-0.1	0.0	-0.5	0.6		X		X				Potentially Pathogenic	The guanidinium group of Arg596, located in an α helix (res. Glu582-Met603), forms a salt bridge with the carboxylate group of Glu495 from another α helix (res. Leu489-Glu519). In the WT simulations, the side chain of Arg596 hydrogen bonds with the backbone carbonyl groups of Asn487, Glu486, Arg485, and Phe484. Additionally, Arg596 can hydrogen bond with the carboxamide group of the Asn487 side chain on an opposing loop that links two α helices (res. Ala461-Arg475, res. Leu489-Glu519).However, in the variant simulations, the branched hydrocarbon side chain of Leu596 cannot form any of the hydrogen bonds or salt bridges maintained by the considerably bulkier and positively charged Arg596 side chain. Instead, Leu596 packs hydrophobically with the phenyl ring of Phe484 in the linker loop or residues from the opposing helix (e.g., Ile494, Thr491).Thus, the residue swap could affect the tertiary structure assembly more profoundly than observed in the simulations. Notably, Arg596 plays a key role in positioning the aforementioned loop, which is crucial for the placement of the “arginine finger” or the Arg485 side chain during RasGTPase activation.	10.1016/j.ajhg.2020.11.011
c.1517T>C	L506P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-12.088	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.737	Likely Pathogenic	5.48	Destabilizing	0.7	10.19	Destabilizing	7.84	Destabilizing	2.50	Destabilizing	-6.96	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	1.55	Pathogenic	0.00	Affected	3.37	35	-3	-3	-5.4	-16.04	182.6	64.9	0.1	0.0	0.2	0.1	X							Potentially Pathogenic	Leu506 is located in the middle of an α-helix (res. Gly502-Tyr518) within the inter-helix space of two helices (res. Gly502-Tyr518 and res. Glu582-Met603). In the WT simulations, the iso-butyl side chain of Leu506 hydrophobically packs with residues in the inter-helix space (e.g., Ile510, Phe597, Leu598, Ala601). In the variant simulations, the cyclic five-membered pyrrolidine ring of Pro506 is not as optimal as Leu506 for hydrophobic packing with nearby residues. Additionally, Pro506 cannot maintain the hydrogen bond with the backbone oxygen of Gly502 as Leu506 does in the WT, which disrupts the secondary structure element.
c.1898T>C	L633P (3D Viewer)	Likely Pathogenic	GAP	Pathogenic/Likely path.		2				-15.669	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.693	Likely Pathogenic	6.60	Destabilizing	0.2	10.15	Destabilizing	8.38	Destabilizing	2.42	Destabilizing	-6.97	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.70	Benign	0.00	Affected	3.37	34	-3	-3	-5.4	-16.04	193.2	65.1	0.0	0.0	0.1	0.0	X							Potentially Pathogenic	The iso-butyl side chain of Leu633, located in the middle of an α helix (res. Glu617-Asn635), packs hydrophobically with nearby residues (e.g., Leu653, Val629, Leu551) in the WT simulations.In the variant simulations, the pyrrolidine side chain of Pro633 is not as optimal for hydrophobic packing as Leu633 in the WT. Additionally, proline lacks a free backbone amide group, so Pro633 cannot form a hydrogen bond with the backbone carbonyl group of Val629, which disrupts the continuity of the secondary structure element.
c.1394T>C	L465P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-14.824	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.778	Likely Pathogenic	7.18	Destabilizing	0.3	10.85	Destabilizing	9.02	Destabilizing	2.73	Destabilizing	-6.96	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.29	Pathogenic	0.00	Affected	3.37	34	-3	-3	-5.4	-16.04	211.1	65.9	0.1	0.0	-0.2	0.0	X							Potentially Pathogenic	The iso-butyl side chain of Leu465, located in the middle of an α helix (res. Ala461–Phe476), packs with hydrophobic residues (e.g., Phe464, Met468, Tyr497, Ile494) in an inter-helix space formed with two other α helices (res. Ala461–Phe476 and res. Thr488-Gly502). In the variant simulations, the cyclic five-membered pyrrolidine ring of Pro465 is not as optimal as the side chain of Leu465 for filling the three α helix hydrophobic niche. Although the residue swap does not cause a large-scale conformational shift during the simulations, the H-bond between the backbone amide group of Leu465 and the backbone carbonyl group of Ala461 is lost. This, in turn, breaks the continuity of the α helix secondary structure element.
c.2087T>C	L696P (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-16.926	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.678	Likely Pathogenic	6.66	Destabilizing	0.2	10.84	Destabilizing	8.75	Destabilizing	2.13	Destabilizing	-6.58	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	3.00	Benign	0.00	Affected	3.46	13	-3	-3	-5.4	-16.04	180.6	65.9	0.1	0.0	-0.6	0.1	X							Potentially Pathogenic	The isobutyl side chain of Leu696, located in the middle of an α-helix (res. Leu685-Gln702), engages in hydrophobic packing with nearby residues (e.g., Leu441, Leu431, Leu692, Leu714) in the inter-helix space. Prolines lack a free amide group necessary for hydrogen bonding with the carbonyl group of Leu692 in the same manner as Leu696 in the WT. Consequently, the residue swap with proline disrupts the continuity of the secondary structure element in the variant simulations. Additionally, the side chain of Pro696 is not as optimal as Leu696 for hydrophobic packing in the inter-helix space.
c.872A>G	Y291C (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-8.997	Likely Pathogenic	0.967	Likely Pathogenic	Likely Pathogenic	0.505	Likely Pathogenic	2.90	Destabilizing	0.4	3.51	Destabilizing	3.21	Destabilizing	1.35	Destabilizing	-7.37	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.76	Pathogenic	0.01	Affected	3.38	23	0	-2	3.8	-60.04	205.2	66.1	0.1	0.0	-0.4	0.4	X						X	Potentially Pathogenic	The phenol group of the Tyr291 side chain, located in an anti-parallel β sheet strand (res. Met289-Pro298), packs against hydrophobic residues of the C2 and PH domains (e.g., Leu317, Leu286, Leu284, Pro208, Val209). The phenol ring of Tyr291 also forms favorable Met-aromatic stacking with the methyl group of Met289. In the variant simulation, the thiol group of the Cys291 side chain is not as suitable for the hydrophobic inter-domain space as the phenol ring of Tyr291. Consequently, the structural unity of the PH domain is weakened and ultimately unfolds in the second simulation. Moreover, the residue swap might result in severe detrimental effects on the C2 domain structure and the C2-PH domain tertiary structure assembly during folding.
c.1706T>C	F569S (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		2				-13.384	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.916	Likely Pathogenic	5.70	Destabilizing	0.1	5.38	Destabilizing	5.54	Destabilizing	2.45	Destabilizing	-7.97	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.32	Pathogenic	0.00	Affected	3.37	34	-3	-2	-3.6	-60.10	213.7	67.9	-0.1	0.0	-1.0	0.1							X	Potentially Pathogenic	Phe569 is located on an α-helix (res. Arg563-Glu578). In the WT simulations, the phenyl side chain of Phe569 packs with hydrophobic residues such as Trp572, Leu565, Ile589, Ile667, and Phe561, originating from three different α-helices (res. Ala533-Val560, res. Arg563-Glu578, and res. Ser641-Glu666). In the variant simulations, the acceptor/donor hydroxyl group of Ser569 forms hydrogen bonds with the carbonyl groups of Glu567 and Lys566 on the same α-helix, which could affect the α-helix integrity, although this is not observed in the simulations. While the simulations do not show large-scale effects, the residue swap could have a substantial impact on the protein structure due to the fundamental role of hydrophobic packing during protein folding.
c.968T>C	L323P (3D Viewer)	Likely Pathogenic	C2	Uncertain		1				-12.507	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.762	Likely Pathogenic	3.39	Destabilizing	0.6	8.46	Destabilizing	5.93	Destabilizing	2.20	Destabilizing	-4.80	Deleterious	0.999	Probably Damaging	0.977	Probably Damaging	0.59	Pathogenic	0.01	Affected	4.29	398	-3	-3	-5.4	-16.04	201.9	68.2	0.0	0.1	0.6	0.3	X							Potentially Pathogenic	The iso-butyl side chain of Leu323, located at the beginning of an anti-parallel β sheet strand (res. Ala322-Asp330), packs against multiple hydrophobic leucine residues (e.g., Leu264, Leu266, Leu284, Leu286). In contrast, in the variant simulations, the less bulky cyclic five-membered pyrrolidine ring of Pro323 cannot fill the hydrophobic space as effectively as the branched hydrocarbon side chain of leucine. Notably, the backbone amide group of Leu323 forms a hydrogen bond with the backbone carbonyl group of Cys285. Pro323 cannot form this bond due to the absence of the backbone amide group, resulting in partial unfolding of the anti-parallel β sheet end in the variant simulations.
c.1403T>A	M468K (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-16.982	Likely Pathogenic	0.978	Likely Pathogenic	Likely Pathogenic	0.828	Likely Pathogenic	3.21	Destabilizing	0.1	3.30	Destabilizing	3.26	Destabilizing	2.57	Destabilizing	-4.61	Deleterious	0.878	Possibly Damaging	0.922	Probably Damaging	-1.34	Pathogenic	0.04	Affected	3.37	31	0	-1	-5.8	-3.02	188.7	69.3	0.0	0.0	-0.1	0.2			X				X	Potentially Pathogenic	The thioether group of Met468, located in the middle of an α helix (res. Ala461–Phe476), interacts with hydrophobic residues (e.g., Phe464, Leu465, Leu489) in an inter-helix space formed by two other α helices (res. Ala461–Phe476, res. Thr488–Gly502). In the variant simulations, the positively charged side chain of Lys468 rotates outward to escape the hydrophobic niche, forming an H-bond with the hydroxyl group of the Ser471 side chain and a salt bridge with the carboxylate group of the Glu472 side chain. This residue swap also disrupts the methionine-aromatic stacking with the phenyl ring of the Phe464 side chain. Although no large-scale structural changes are observed during the variant simulations, the importance of hydrophobic packing suggests that the effects could be more pronounced during protein folding.
c.980T>C	L327P (3D Viewer)	Likely Pathogenic	C2	Pathogenic		3				-16.602	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.658	Likely Pathogenic	5.38	Destabilizing	0.1	4.00	Destabilizing	4.69	Destabilizing	2.62	Destabilizing	-5.97	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.52	Pathogenic	0.01	Affected	3.38	23	-3	-3	-5.4	-16.04	221.7	69.4	0.1	0.0	0.6	0.1	X							Potentially Pathogenic	The backbone amide group of Leu327, located in the middle of an anti-parallel β sheet strand (res. Ala322-Asp330), forms a hydrogen bond with the carbonyl group of Gly344 on a neighboring β strand (res. Lys336-Pro349) in the WT simulations. In contrast, in the variant simulations, the introduction of Pro327 destabilizes the hydrogen bonding between the two anti-parallel β strands because proline lacks the backbone amide group altogether. Additionally, in the WT simulations, the iso-butyl side chain of Leu327 packs against multiple hydrophobic residues (e.g., Leu274, V400, Val343), whereas the less bulky cyclic five-membered pyrrolidine ring of Pro327 cannot fill the same space as effectively. Thus, although no large-scale unfolding is observed during the variant simulations, the residue swap is likely to cause severe problems for the correct C2 domain folding, which could also affect the SynGAP-membrane association.	10.1016/j.ajhg.2020.11.011
c.896G>A	R299H (3D Viewer)		C2	Conflicting		2	6-33437801-G-A	10	6.20e-6	-7.731	In-Between	0.388	Ambiguous	Likely Benign	0.238	Likely Benign	3.97	Destabilizing	1.0	0.94	Ambiguous	2.46	Destabilizing	1.41	Destabilizing	-3.35	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.69	Pathogenic	0.02	Affected	3.39	19	2	0	1.3	-19.05	211.2	72.5	-0.1	0.2	-0.2	0.3	X							Potentially Pathogenic	The guanidinium group of Arg299, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Met289-Pro298, res. Thr305-Asn315), forms hydrogen bonds that stabilize the tight turn. In the WT simulations, the Arg299 side chain hydrogen bonds with the loop backbone carbonyl groups (e.g., Ser302, Thr305, Leu274, Gly303), the hydroxyl group of Ser300, and even forms a salt bridge with the carboxylate group of Asp304.In the variant simulations, the imidazole ring of His299 (epsilon protonated state) hydrogen bonds with the carbonyl group of Asp304 and the hydroxyl group of Ser300. However, it does not form as many or as strong interactions as arginine, which could affect the initial formation of the secondary hairpin loop during folding. β hairpins are potential nucleation sites during the initial stages of protein folding, so even minor changes in them could be significant.Additionally, His299 prefers to hydrophobically interact with other hydrophobic residues inside the C2 domain core (e.g., Val306, Leu274), which destabilizes the C2 domain. Indeed, the β strand partially unfolds during the second simulation. Moreover, the positively charged Arg299 side chain faces the polar head group region of the inner leaflet membrane and could directly anchor the C2 domain to the membrane. In short, the residue swap could negatively affect both protein folding and the stability of the SynGAP-membrane association.
c.1715G>C	W572S (3D Viewer)	Likely Pathogenic	GAP	Pathogenic		1				-17.461	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.775	Likely Pathogenic	5.78	Destabilizing	0.2	3.37	Destabilizing	4.58	Destabilizing	1.79	Destabilizing	-12.74	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.24	Pathogenic	0.01	Affected	3.37	35	-2	-3	0.1	-99.14	235.1	76.6	0.0	0.0	-0.4	0.1							X	Potentially Pathogenic	The introduced residue Ser572, located in an α-helix (res. Arg563-Glu578), is considerably smaller than the tryptophan it replaced. The indole ring of the Trp572 side chain lies in a hydrophobic inter-helix space, where it makes extensive hydrophobic interactions with nearby residues such as Met470, Phe569, Leu588, and Ile589. In the variant simulations, all these favorable packing interactions are completely removed, as the introduced residue Ser572 is too hydrophilic or small to fill the hydrophobic niche occupied by the indole ring. Moreover, the hydroxyl group of Ser572 forms hydrogen bonds with the carbonyl groups of Glu567 and Val568 within the same α-helix, potentially lowering its integrity. Overall, the residue swap is highly likely to cause critical protein folding problems that are underestimated based on the effects seen in the variant simulations.
c.1025A>C	Y342S (3D Viewer)	Likely Pathogenic	C2	Uncertain		2				-7.996	In-Between	0.925	Likely Pathogenic	Ambiguous	0.407	Likely Benign	3.03	Destabilizing	0.1	2.87	Destabilizing	2.95	Destabilizing	0.93	Ambiguous	-6.60	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.75	Pathogenic	0.04	Affected	3.37	25	-3	-2	0.5	-76.10	200.1	77.8	0.0	0.0	-0.2	0.1								Potentially Pathogenic	The phenol ring of Tyr342, located at the end of an anti-parallel β sheet strand (res. Gly341-Pro349), faces outward in the C2 domain. In the WT simulations, the phenol ring of Tyr342 contributes to a triple tyrosine stack (Tyr342, Tyr328, and Tyr281) that links together three anti-parallel β sheet strands. Additionally, it shields Gly344 from the solvent, reducing its exposure and providing stability for the β-sandwich. This motif also contributes to a twist formation in the β sheet.In the variant simulations, the Ser342 side chain cannot participate in the stack formation. Instead, the hydroxyl group of the Ser342 side chain forms a hydrogen bond with the imidazole ring of His326 in a neighboring β strand (res. Ala322-Asp330). This disrupts the formation of a hydrogen bond between His326 and the carboxylate group of the Glu283 side chain from another β strand (res. Arg279-Cys285). Although these changes in surface interactions could weaken the characteristic twist that strengthens the β sheet fold, no major structural effects are observed in the variant simulations. The residue swap could also affect the SynGAP-membrane association, as the hydroxyl group of Ser342 could form hydrogen bonds with membrane-facing loop residues. However, this phenomenon cannot be addressed using solvent-only simulations.
c.1544G>A	R515H (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1	6-33438787-G-A	3	1.86e-6	-10.774	Likely Pathogenic	0.337	Likely Benign	Likely Benign	0.730	Likely Pathogenic	1.07	Ambiguous	0.2	0.74	Ambiguous	0.91	Ambiguous	1.09	Destabilizing	-3.44	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	-1.32	Pathogenic	0.01	Affected	3.37	35	2	0	1.3	-19.05	239.2	77.8	0.0	0.0	0.4	0.2		X						Potentially Benign	The guanidinium group of Arg515, located in the middle of an α-helix at the GAP domain (res. Gly502-Tyr518), forms salt bridges with the carboxylate groups of Glu512 on the same helix and Glu217 on a loop in the PH domain. Additionally, the positively charged Arg515 side chain forms hydrogen bonds with Leu610 and Gln612 in an opposing loop (res. Gly609-Asp616). In contrast, in the variant simulations, the imidazole ring of His515 cannot form salt bridges with either of the acidic residues, and its side chain is too short to form hydrogen bonds with the loop residues. Accordingly, the residue swap could weaken the tertiary structure assembly of the protein. Due to the missing N-terminal part of the SynGAP model, the effect could be largely underestimated or missing. Notably, the doubly protonated and positively charged form of histidine was not simulated here.
c.1787G>A	R596H (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33440839-G-A	15	9.29e-6	-11.128	Likely Pathogenic	0.950	Likely Pathogenic	Ambiguous	0.717	Likely Pathogenic	3.00	Destabilizing	0.9	0.43	Likely Benign	1.72	Ambiguous	1.35	Destabilizing	-4.97	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	2.43	Pathogenic	0.00	Affected	3.37	35	2	0	1.3	-19.05	223.5	80.5	-0.1	0.0	-0.1	0.3		X		X				Potentially Pathogenic	The guanidinium group of Arg596, located in an α helix (res. Glu582-Met603), forms a salt bridge with the carboxylate group of Glu495 from another α helix (res. Leu489-Glu519). In the WT simulations, the side chain of Arg596 hydrogen bonds with the backbone carbonyl groups of Asn487, Glu486, Arg485, and Phe484. Additionally, Arg596 can hydrogen bond with the carboxamide group of the Asn487 side chain on an opposing loop that links two α helices (res. Ala461-Arg475, res. Leu489-Glu519).In the variant simulations, the imidazole ring of His596 can form hydrogen bonds with the same residues as arginine; however, these interactions are not as coordinated or strong in comparison. Thus, the residue swap could affect the tertiary structure assembly more profoundly than observed in the simulations. Notably, Arg596 plays a key role in positioning the aforementioned loop, which is crucial for the placement of the “arginine finger” or the Arg485 side chain during RasGTPase activation.
c.1724G>A	R575H (3D Viewer)		GAP	Conflicting		4	6-33440776-G-A	204	1.27e-4	-11.142	Likely Pathogenic	0.496	Ambiguous	Likely Benign	0.707	Likely Pathogenic	0.81	Ambiguous	0.2	-0.22	Likely Benign	0.30	Likely Benign	1.31	Destabilizing	-2.34	Neutral	1.000	Probably Damaging	0.998	Probably Damaging	-1.33	Pathogenic	0.05	Affected	3.37	35	2	0	1.3	-19.05	244.7	80.6	0.0	0.0	0.3	0.0		X						Potentially Pathogenic	The guanidinium group of Arg575, located in an α-helix (res. Arg563-Glu578), forms salt bridges with the carboxylate groups of Asp463 and Asp467, and it also hydrogen bonds with the hydroxyl group of Ser466 on an opposing α-helix (res. Ala461-Phe476) in the WT simulations. In the variant simulations, the imidazole ring of His575 (in its neutral epsilon protonated form) cannot form the same salt bridges as the guanidinium group of the non-mutated Arg575. Instead, His575 only forms weak hydrogen bonds with the hydroxyl groups of Ser466 and Ser571. Overall, the residue swap has the potential to substantially affect the tertiary structure assembly during the protein folding process.
c.986G>A	R329H (3D Viewer)	Likely Pathogenic	C2	Uncertain		1	6-33437891-G-A	2	1.24e-6	-10.154	Likely Pathogenic	0.769	Likely Pathogenic	Likely Benign	0.155	Likely Benign	2.53	Destabilizing	0.7	0.71	Ambiguous	1.62	Ambiguous	0.82	Ambiguous	-3.17	Deleterious	0.995	Probably Damaging	0.778	Possibly Damaging	4.04	Benign	0.05	Affected	3.41	15	2	0	1.3	-19.05	220.4	81.4	0.1	0.1	0.2	0.3								Uncertain	The guanidinium group of Arg329, located at the end of an anti-parallel β sheet strand (res. Ala322-Asp330), faces the negatively charged lipid bilayer surface. While the residue swap does not cause any apparent negative effects on the protein structure in the variant simulations, it could adversely affect the SynGAP-membrane association in reality. The positively charged Arg329 side chain forms hydrogen bonds with other loop residues (e.g., Ser371, Asp338) that are expected to dynamically interact with the membrane head group region. However, this phenomenon is beyond the scope of the solvent-only simulations to unravel. Notably, histidine can also be double protonated and positively charged, but this alternative protonation state was not considered in the variant simulations.
c.773G>A	R258H (3D Viewer)		C2	Benign/Likely benign		3	6-33437678-G-A	10	6.20e-6	-10.533	Likely Pathogenic	0.525	Ambiguous	Likely Benign	0.830	Likely Pathogenic	1.60	Ambiguous	0.6	1.00	Ambiguous	1.30	Ambiguous	1.47	Destabilizing	-4.06	Deleterious	1.000	Probably Damaging	0.991	Probably Damaging	5.77	Benign	0.01	Affected	3.39	15	2	0	1.3	-19.05	212.5	81.8	0.1	0.0	-0.5	0.2		X						Potentially Pathogenic	The guanidinium group of Arg258, located at the end of an α-β loop connecting the PH domain to the C2 domain (res. Lys251-Arg258), forms hydrogen bonds with the carboxamide groups of Asn727 and Asn729 side chains, as well as with the backbone carbonyl groups of Ala724, Leu725, and Asn727 in the WT simulations. Although the imidazole group of His258 can act as a hydrogen bond donor/acceptor, the swapped residue is unable to maintain an equally well-coordinated hydrogen bond network for linking the C2 and GAP domains in the variant simulations.
c.1004G>A	R335H (3D Viewer)	Likely Pathogenic	C2	Uncertain		1	6-33437909-G-A	2	1.24e-6	-12.521	Likely Pathogenic	0.831	Likely Pathogenic	Ambiguous	0.132	Likely Benign	0.58	Ambiguous	0.1	0.22	Likely Benign	0.40	Likely Benign	0.72	Ambiguous	-3.02	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.70	Pathogenic	0.03	Affected	3.38	22	2	0	1.3	-19.05	242.4	82.1	-2.4	0.6	-0.1	0.1								Uncertain	The guanidinium group of Arg335, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Ala322-Asp330, res. Gly341-Pro349), faces the post-synaptic inner membrane surface. In the WT simulations, the Arg335 side chain dynamically forms salt bridges with the carboxylate groups of Asp322, Asp338, and Asp616. In contrast, the imidazole ring of His335, which is not double protonated and thus not positively charged in the variant simulations, continues to move dynamically without forming any lasting or strong interactions. Importantly, the positively charged arginine residues of the C2 domain are ideal membrane anchors for ensuring SynGAP-membrane association. However, this phenomenon cannot be addressed using solvent-only simulations.
c.1213C>T	R405C (3D Viewer)	Likely Pathogenic	C2	Conflicting		2	6-33438118-C-T	6	3.72e-6	-9.206	Likely Pathogenic	0.713	Likely Pathogenic	Likely Benign	0.427	Likely Benign	0.72	Ambiguous	0.1	1.51	Ambiguous	1.12	Ambiguous	1.21	Destabilizing	-7.27	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	3.61	Benign	0.02	Affected	3.38	28	-4	-3	7.0	-53.05	221.3	82.6	-0.1	0.0	-0.2	0.3	X	X						Potentially Pathogenic	The guanidinium group of Arg405, located in an anti-parallel β sheet strand of the C2 domain (res. Ala399-Ile411), forms a salt bridge with the carboxylate group of the Glu446 side chain from an opposing α helix (res. Val441-Ser457) in the GAP domain. The positively charged Arg405 side chain also stacks with the aromatic ring of the Phe358 side chain from a loop preceding the β strand (res. Thr359-Thr366), which could assist in maintaining the anti-parallel strand arrangement.In the variant simulations, the thiol-containing side chain of Cys405 is neutral and smaller compared to the arginine side chain. The lack of Arg405-Phe358 stacking affects the loop structure, causing it to assume a β strand form—an effect that could be exacerbated during protein folding. Moreover, the inability of Cys405 to form a salt bridge with Glu446 could affect the tertiary structure assembly, although this is not apparent based on the variant simulations.
c.1556A>C	E519A (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-8.557	Likely Pathogenic	0.904	Likely Pathogenic	Ambiguous	0.384	Likely Benign	-0.05	Likely Benign	0.0	0.55	Ambiguous	0.25	Likely Benign	0.00	Likely Benign	-5.23	Deleterious	0.999	Probably Damaging	0.998	Probably Damaging	3.33	Benign	0.10	Tolerated	3.37	35	0	-1	5.3	-58.04	162.4	83.5	-0.1	0.1	-0.2	0.0						X		Potentially Benign	Glu519 is located at the beginning of an α-α loop between the two α-helices (res. Gly502-Tyr518 and Ala533-Val560). In the WT simulations, the carboxylate side chain of Glu519 does not make any specific interactions. Accordingly, the Ala residue swap does not show any negative structural effects in the variant simulations. However, it should be noted that Glu519 faces the missing part of the N-terminal in the model, and thus its potential role in maintaining the tertiary structure might be de-emphasized in the current model.
c.962G>A	R321H (3D Viewer)		C2	Uncertain		1	6-33437867-G-A	8	4.96e-6	-8.751	Likely Pathogenic	0.136	Likely Benign	Likely Benign	0.323	Likely Benign	0.48	Likely Benign	0.1	-0.36	Likely Benign	0.06	Likely Benign	0.59	Ambiguous	-1.43	Neutral	1.000	Probably Damaging	0.998	Probably Damaging	1.92	Pathogenic	0.25	Tolerated	3.38	23	2	0	1.3	-19.05	218.5	86.9	1.1	0.0	0.3	0.0						X		Potentially Benign	The guanidinium group of Arg321, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Thr305-Asn315, res. Ala322-Asp330), faces outward without forming any stable interactions in the WT simulations. Similarly, in the variant simulations, the imidazole ring of His321 also points outward without making any stable intra-protein interactions. Thus, the residue swap does not seem to cause adverse effects on the protein structure based on the simulations. However, β hairpins are potential nucleation sites during the initial stages of protein folding, so even minor changes in them could be significant.
c.1760G>C	R587T (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-9.697	Likely Pathogenic	0.784	Likely Pathogenic	Likely Benign	0.603	Likely Pathogenic	1.14	Ambiguous	0.2	0.74	Ambiguous	0.94	Ambiguous	0.98	Ambiguous	-4.71	Deleterious	0.998	Probably Damaging	0.847	Possibly Damaging	-1.19	Pathogenic	0.08	Tolerated	3.37	35	-1	-1	3.8	-55.08	227.2	87.4	0.0	0.0	0.5	0.1		X						Potentially Pathogenic	The guanidinium group of Arg587, located on an α helix (res. Glu582-Met603), is constantly rotating and breaking/forming multiple hydrogen bonds and/or salt bridges at the surface intersection of α helices in the WT simulations. The positively charged Arg587 side chain can form a salt bridge with either the carboxylate group of Asp583 or Asp586 in the same helix, or with Glu480 on the opposing short helical loop structure (res. Glu480-Leu482).Importantly, the Arg587 side chain also hydrogen bonds with the backbone carbonyl groups of Ala634 and Asn635, as well as the carboxamide group of Asn635 at the end of another α helix (res. Asp616-Phe636). However, in the variant simulations, the neutral hydroxyl group of the Thr587 side chain is unable to form these salt bridges. Due to its smaller size, it also does not form the hydrogen bonds that the Arg587 side chain could. Instead, the hydroxyl group of Thr587 hydrogen bonds with the backbone carbonyl group of Asp583, which could weaken the integrity of the α helix, although this is not observed in the simulations.Overall, the residue swap could weaken the tertiary structure assembly and negatively affect the overall protein folding process.
c.1066C>T	R356C (3D Viewer)	Likely Pathogenic	C2	Likely Benign		1	6-33437971-C-T	5	3.10e-6	-11.827	Likely Pathogenic	0.774	Likely Pathogenic	Likely Benign	0.312	Likely Benign	0.76	Ambiguous	0.0	1.19	Ambiguous	0.98	Ambiguous	0.84	Ambiguous	-7.12	Deleterious	1.000	Probably Damaging	0.990	Probably Damaging	1.67	Pathogenic	0.00	Affected	3.39	22	-4	-3	7.0	-53.05	212.3	91.0	-0.1	0.3	-0.3	0.1		X						Potentially Pathogenic	Arg356 is located in a loop that includes a short helical section and connects two anti-parallel β sheet strands (res. Gly341-Pro349, res. Thr359-Pro364). In the WT simulations, the guanidinium group of Arg356 alternately forms salt bridges with the carboxylate groups of the GAP domain residues, Glu446 and Glu698. Arg356 also forms hydrogen bonds with the hydroxyl group of the GAP domain residue Thr691 and interacts with Met409 at the C2-GAP interface.In the variant simulations, the Cys356 mutation fails to maintain any of the Arg356 interactions and only occasionally forms weak hydrogen bonds with nearby C2 domain residues (e.g., Gln407). Although no negative structural effects are observed during the simulations, Arg356 is located at the C2 and GAP domain interface, making the residue swap potentially detrimental to the tertiary structure assembly.
c.895C>T	R299C (3D Viewer)	Likely Pathogenic	C2	Conflicting		2	6-33437800-C-T	3	1.86e-6	-6.326	Likely Benign	0.572	Likely Pathogenic	Likely Benign	0.344	Likely Benign	1.85	Ambiguous	0.4	0.61	Ambiguous	1.23	Ambiguous	0.76	Ambiguous	-3.54	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.65	Pathogenic	0.06	Tolerated	3.39	19	-4	-3	7.0	-53.05	210.7	91.3	0.1	0.0	0.0	0.2	X	X						Potentially Pathogenic	The guanidinium group of Arg299, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Met289-Pro298, res. Thr305-Asn315), forms hydrogen bonds that stabilize the tight turn. In the WT simulations, the Arg299 side chain hydrogen bonds with the loop backbone carbonyl groups (e.g., Ser302, Thr305, Leu274, Gly303), the hydroxyl group of Ser300, and even forms a salt bridge with the carboxylate group of Asp304.In the variant simulations, the thiol group of the Cys299 side chain is unable to form any of these well-coordinated or strong interactions, which could affect the initial formation of the secondary hairpin loop during folding. β hairpins are potential nucleation sites during the initial stages of protein folding, so even minor changes in them could be significant. Moreover, the positively charged Arg299 side chain faces the polar head group region of the inner leaflet membrane and could directly anchor the C2 domain to the membrane. In short, the residue swap could negatively affect both protein folding and the stability of the SynGAP-membrane association.
c.877C>T	R293C (3D Viewer)	Likely Pathogenic	C2	Uncertain		1	6-33437782-C-T	3	1.86e-6	-12.844	Likely Pathogenic	0.985	Likely Pathogenic	Likely Pathogenic	0.579	Likely Pathogenic	1.38	Ambiguous	0.1	0.62	Ambiguous	1.00	Ambiguous	0.02	Likely Benign	-7.35	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.46	Pathogenic	0.00	Affected	3.38	23	-4	-3	7.0	-53.05	226.0	96.5	0.0	0.0	0.1	0.1		X		X			X	Potentially Pathogenic	The guanidinium group of the Arg293 side chain, located in an anti-parallel β sheet strand (res. Met289-Pro298), packs against the phenol ring of the Tyr281 side chain or forms a salt bridge with the carboxylate group of Glu283 on the outer side of the C2 domain. The positively charged guanidinium side chain of arginine is on the outside surface of the hydrophobic C2 domain, resulting in a twist in the β strand. Although this twist is maintained in the variant simulations, replacing the positively charged residue with a more hydrophobic one, such as cysteine, could remove the twist during protein folding.Because Arg293 is positioned at the C2 and PH domain interface, the residue swap could significantly impact the tertiary structure assembly. Notably, Arg293 is located at the SynGAP-Ras interface, and its role in complex formation cannot be fully understood through solvent-only simulations.
c.1786C>T	R596C (3D Viewer)	Likely Pathogenic	GAP	Conflicting		2	6-33440838-C-T	6	3.72e-6	-10.805	Likely Pathogenic	0.972	Likely Pathogenic	Likely Pathogenic	0.633	Likely Pathogenic	2.94	Destabilizing	0.0	1.49	Ambiguous	2.22	Destabilizing	-0.03	Likely Benign	-7.96	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.41	Pathogenic	0.00	Affected	3.37	35	-4	-3	7.0	-53.05	230.7	97.9	-0.1	0.0	-0.3	0.4		X		X				Potentially Pathogenic	The guanidinium group of Arg596, located in an α helix (res. Glu582-Met603), forms a salt bridge with the carboxylate group of Glu495 from another α helix (res. Leu489-Glu519). In the WT simulations, the side chain of Arg596 hydrogen bonds with the backbone carbonyl groups of Asn487, Glu486, Arg485, and Phe484. Additionally, Arg596 can hydrogen bond with the carboxamide group of the Asn487 side chain on an opposing loop that links two α helices (res. Ala461-Arg475, res. Leu489-Glu519).In the variant simulations, the thiol group of the Cys596 side chain is unable to form salt bridges or any of the hydrogen bonds that the Arg596 side chain can. Thus, the residue swap could affect the tertiary structure assembly more profoundly than observed in the simulations. Notably, Arg596 plays a key role in positioning the aforementioned loop, which is crucial for the placement of the “arginine finger” or the Arg485 side chain during RasGTPase activation.
c.1997A>G	E666G (3D Viewer)	Likely Pathogenic	GAP	Likely Benign		1	6-33441256-A-G	10	6.20e-6	-12.261	Likely Pathogenic	0.911	Likely Pathogenic	Ambiguous	0.522	Likely Pathogenic	1.57	Ambiguous	0.1	1.46	Ambiguous	1.52	Ambiguous	0.93	Ambiguous	-6.25	Deleterious	1.000	Probably Damaging	0.970	Probably Damaging	3.37	Benign	0.02	Affected	3.38	28	0	-2	3.1	-72.06	173.9	98.5	0.0	0.0	-0.7	0.0		X						Potentially Pathogenic	In the WT simulations, the carboxylate group of Glu666, located on the α-helix (res. Ser641-Glu666), is involved in a highly coordinated hydrogen-bonding network between residues from two α-helices (res. Ser641-Glu666 and res. Arg563-Glu578) and from the α-α loop connecting the two α-helices (res. Ser641-Glu666 and res. Leu685-Val699), such as Lys566, Thr672, and Asn669. In the variant simulations, the carbonyl group of Gly666 occasionally forms hydrogen bonds with Lys566 and Asn669. However, Gly666 lacks a side chain and thus cannot maintain as well-coordinated a hydrogen-bond network as Glu666 in the WT, which may affect the tertiary structure assembly.
c.1723C>T	R575C (3D Viewer)	Likely Pathogenic	GAP	Conflicting		3	6-33440775-C-T	23	1.43e-5	-11.179	Likely Pathogenic	0.630	Likely Pathogenic	Likely Benign	0.715	Likely Pathogenic	1.39	Ambiguous	0.2	0.50	Ambiguous	0.95	Ambiguous	0.73	Ambiguous	-5.43	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.30	Pathogenic	0.02	Affected	3.37	35	-4	-3	7.0	-53.05	227.7	99.2	0.0	0.0	0.0	0.1		X						Potentially Pathogenic	The guanidinium group of Arg575, located in an α-helix (res. Arg563-Glu578), forms salt bridges with the carboxylate groups of Asp463 and Asp467, and it also hydrogen bonds with the hydroxyl group of Ser466 on an opposing α-helix (res. Ala461-Phe476) in the WT simulations. In the variant simulations, the thiol group of the Cys575 side chain, which is neither positively charged nor particularly hydrophilic, packs against the hydrophobic Met470 on an opposing α-helix (res. Ala461-Arg475). Additionally, although the thiol group is not an effective hydrogen bonder, the Cys575 side chain rotates to hydrogen bond with the backbone carbonyl group of Ser571 in the same α-helix, which could theoretically lower the helix integrity. Overall, the residue swap has the potential to substantially affect the tertiary structure assembly during the protein folding process.
c.1453C>T	R485C (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2	6-33438485-C-T	9	5.58e-6	-14.294	Likely Pathogenic	0.976	Likely Pathogenic	Likely Pathogenic	0.597	Likely Pathogenic	1.00	Ambiguous	0.1	0.26	Likely Benign	0.63	Ambiguous	0.44	Likely Benign	-7.96	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	1.90	Pathogenic	0.00	Affected	3.37	35	-4	-3	7.0	-53.05	225.5	99.6	-0.1	0.0	-0.3	0.2				X				Uncertain	The guanidinium group of Arg485 is located in a short helical structure (res. Glu480-Leu482) within an α-α loop connecting the two α-helices (res. Ala461-Phe476 and Leu489-Glu519) at the GAP-Ras interface. The side chain of Arg485 acts as the “arginine finger” of SynGAP, playing a crucial role in Ras-GTPase activation. Consequently, the residue swap inhibits the conversion of GTP to GDP at the enzyme’s active site. Although no negative effects on the protein structure are observed during the simulations, no definite conclusions can be drawn due to the critical role of Arg485 in GTPase activation.
c.1214G>A	R405H (3D Viewer)	Likely Pathogenic	C2	Conflicting		2	6-33438119-G-A	4	2.48e-6	-9.081	Likely Pathogenic	0.706	Likely Pathogenic	Likely Benign	0.371	Likely Benign	2.79	Destabilizing	0.6	1.85	Ambiguous	2.32	Destabilizing	1.26	Destabilizing	-4.54	Deleterious	1.000	Probably Damaging	0.991	Probably Damaging	3.65	Benign	0.01	Affected	3.38	28	2	0	1.3	-19.05	214.0	102.2	-0.1	0.0	-0.7	0.1		X						Potentially Pathogenic	The guanidinium group of Arg405, located in an anti-parallel β sheet strand of the C2 domain (res. Pro398-Ile411), forms a salt bridge with the carboxylate group of the Glu446 side chain from an opposing α helix (res. Val441-Ser457) in the GAP domain. The positively charged Arg405 side chain also stacks with the aromatic ring of the Phe358 side chain from a loop preceding the β strand (res. Thr359-Thr366), which could assist in maintaining the anti-parallel strand arrangement.In the variant simulations, the imidazole ring of His405 does not stack with the aromatic ring of Phe358 nor form any lasting H-bonds with the loop residues. The imidazole ring of His405 (neutral and epsilon protonated in the simulations) is unable to form a salt bridge with Glu446, which could affect the tertiary structure assembly, although this is not apparent based on the variant simulations.
c.1487A>G	E496G (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-13.529	Likely Pathogenic	0.850	Likely Pathogenic	Ambiguous	0.825	Likely Pathogenic	1.83	Ambiguous	0.1	1.76	Ambiguous	1.80	Ambiguous	0.92	Ambiguous	-6.16	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	-1.45	Pathogenic	0.02	Affected	3.37	35	0	-2	3.1	-72.06	173.9	103.1	0.0	0.0	-0.7	0.0		X		X				Potentially Pathogenic	Glu496 is located in the α-helix (res. Leu489-Glu519), and its carboxylate group forms salt bridges with the neighbouring residues Lys492 and Arg499 in the WT simulations. Glu496 also forms a hydrogen bond with Ser449 on an opposing helix (res. Val441-Ser457). In the variant simulations, Gly496 cannot form these salt bridges, which could weaken the secondary structure. Additionally, the loss of the hydrogen bond with Ser449 on the opposite helix can weaken the tertiary structure assembly. Moreover, glycine is an α-helix breaker, and it is seen to weaken the integrity of the helix as the hydrogen bonding between the backbone atoms of Gly496 and Ala493 breaks down. Also, due to its location at the GAP-Ras interface, the interaction of Glu496 with Arg499 and Lys492 might play a role in complex association and stability, which cannot be fully addressed using the SynGAP solvent-only simulations.
c.1256A>G	E419G (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-10.589	Likely Pathogenic	0.956	Likely Pathogenic	Likely Pathogenic	0.469	Likely Benign	1.41	Ambiguous	0.0	1.94	Ambiguous	1.68	Ambiguous	0.83	Ambiguous	-6.42	Deleterious	1.000	Probably Damaging	0.997	Probably Damaging	3.31	Benign	0.02	Affected	3.37	29	0	-2	3.1	-72.06	165.3	110.8	0.0	0.0	-0.1	0.0		X						Potentially Pathogenic	The carboxylate group of Glu419, located on an α helix (res. Met414-Glu436), forms a salt bridge with the side chain of either Arg716 or Lys418 from an opposing helix (res. Pro713-Arg726). The backbone amide group of Glu419 does not form H-bonds, resulting in a slight bend in the α helix. Thus, although glycine is known as an “α helix breaker,” the residue swap does not disrupt the continuity or integrity of the α helix. However, because Gly419 cannot form a salt bridge with the guanidinium group of the Arg716 side chain, the C2-GAP domain tertiary structure could be compromised during folding.
c.1631G>C	R544P (3D Viewer)	Likely Pathogenic	GAP	Uncertain		2				-16.905	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.762	Likely Pathogenic	4.70	Destabilizing	0.1	4.19	Destabilizing	4.45	Destabilizing	1.14	Destabilizing	-4.88	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.48	Pathogenic	0.05	Affected	3.37	35	0	-2	2.9	-59.07	192.0	123.8	0.1	0.0	-0.3	0.0	X	X						Potentially Pathogenic	Arg544 is located in the middle of an α-helix (res. Ala533-Val560). In the WT simulations, the guanidinium side chain of Arg544 forms a salt bridge with the carboxylate groups of Glu548 on the same α-helix, and with Glu651 and Glu656 on an opposing α-helix (res. Glu666-Asp644). In the variant simulations, the pyrrolidine side chain of Pro544 cannot form any of the salt bridges that Arg544 does in the WT, potentially weakening the tertiary structure assembly. Additionally, Pro544 lacks the amide group, and thus, unlike Arg544 in the WT, is unable to form a hydrogen bond with the carbonyl of Gln540. This disruption breaks the continuity of the secondary structure element, causing the α-helix to bend slightly in the variant simulations. These negative structural effects could be more pronounced during protein folding and are likely to be undermined in the MD simulations.
c.743G>C	R248P (3D Viewer)	Likely Pathogenic	PH	Likely Pathogenic		1				-10.751	Likely Pathogenic	1.000	Likely Pathogenic	Likely Pathogenic	0.848	Likely Pathogenic	3.09	Destabilizing	0.6	8.87	Destabilizing	5.98	Destabilizing	1.21	Destabilizing	-5.97	Deleterious	0.998	Probably Damaging	0.878	Possibly Damaging	5.64	Benign	0.00	Affected	3.41	14	0	-2	2.9	-59.07	223.8	126.6	0.0	0.0	-0.2	0.1	X	X						Potentially Pathogenic	The guanidinium group of Arg248, located on an α helix (residues Ala236-Val250), forms two very stable salt bridges with Asp255 (from a short α helical section, res. Lys254-Asn256) and Glu244 (from a nearby loop) in the WT simulations. In the variant simulations, the pyrrolidine side chain of Pro248 cannot form any salt bridges, which could negatively affect the tertiary structure assembly of the PH domain. Additionally, Pro248 lacks a free amide group needed for hydrogen bonding with the backbone carbonyl group of Asn245, disrupting the continuity of the α helix.
c.1714T>G	W572G (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-17.692	Likely Pathogenic	0.997	Likely Pathogenic	Likely Pathogenic	0.900	Likely Pathogenic	6.57	Destabilizing	0.2	7.57	Destabilizing	7.07	Destabilizing	1.83	Destabilizing	-11.98	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	-1.24	Pathogenic	0.00	Affected	3.37	35	-7	-2	0.5	-129.16	195.2	127.9	0.0	0.0	-1.0	0.0							X	Potentially Pathogenic	The introduced residue Gly572, located in an α-helix (res. Arg563-Glu578), is considerably smaller than the tryptophan it replaced. The indole ring of the Trp572 side chain lies in a hydrophobic inter-helix space, where it makes extensive hydrophobic interactions with nearby residues such as Met470, Phe569, Leu588, and Ile589. In the variant simulations, all these favorable packing interactions are completely removed, as the introduced residue Gly572 essentially lacks a side chain altogether. Although not observed in the simulations, the residue swap could also weaken the integrity of the helix (res. Arg563-Glu578), as glycine is known as an “α-helix breaker.” Overall, the residue swap is highly likely to cause critical protein folding problems that are underestimated based on the effects seen in the variant simulations.
c.878G>C	R293P (3D Viewer)	Likely Pathogenic	C2	Likely Pathogenic		1				-16.275	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.497	Likely Benign	3.62	Destabilizing	0.4	9.06	Destabilizing	6.34	Destabilizing	0.47	Likely Benign	-6.43	Deleterious	1.000	Probably Damaging	0.999	Probably Damaging	1.45	Pathogenic	0.01	Affected	3.38	23	0	-2	2.9	-59.07	202.3	132.0	0.1	0.0	0.1	0.1	X	X		X				Potentially Pathogenic	The guanidinium group of the Arg293 side chain, located in an anti-parallel β sheet strand (res. Met289-Pro298), packs against the phenol ring of the Tyr281 side chain or forms a salt bridge with the carboxylate group of Glu283 on the outer side of the C2 domain. In the WT simulations, the positively charged side chain of arginine remains outside the hydrophobic C2 domain, resulting in a twist in the β strand. The backbone amide bond of Arg293 potentially maintains this twist by forming a hydrogen bond with the carbonyl group of His210 or the hydroxyl group of Ser211 in the anti-parallel β sheet.Although this twist is also maintained in the variant simulations, replacing the positively charged residue with proline, which lacks the backbone amide group altogether, causes the β strand to unfold. Because Arg293 is positioned at the C2 and PH domain interface, the residue swap could significantly impact the tertiary structure assembly. Notably, Arg293 is located at the SynGAP-Ras interface, and its role in complex formation cannot be fully understood through solvent-only simulations.