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.92G>A	R31Q	Likely Benign		Uncertain		1	6-33423501-G-A	7	4.34e-6	-4.434	Likely Benign	0.136	Likely Benign	Likely Benign	0.051	Likely Benign										-0.92	Neutral	0.829	Possibly Damaging	0.614	Possibly Damaging	4.01	Benign	0.00	Affected	4.32	1	1	1	1.0	-28.06
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.971G>A	R324Q (3D Viewer)	Likely Benign	C2	Uncertain		3	6-33437876-G-A	3	1.86e-6	-5.001	Likely Benign	0.173	Likely Benign	Likely Benign	0.307	Likely Benign	0.56	Ambiguous	0.1	0.63	Ambiguous	0.60	Ambiguous	1.02	Destabilizing	-1.17	Neutral	0.999	Probably Damaging	0.994	Probably Damaging	1.92	Pathogenic	0.41	Tolerated	3.39	22	1	1	1.0	-28.06
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.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.901G>A	A301T (3D Viewer)	Likely Benign	C2	Uncertain		5	6-33437806-G-A	2	1.24e-6	-3.448	Likely Benign	0.070	Likely Benign	Likely Benign	0.150	Likely Benign	0.36	Likely Benign	0.2	-0.33	Likely Benign	0.02	Likely Benign	0.03	Likely Benign	-0.25	Neutral	0.997	Probably Damaging	0.989	Probably Damaging	4.15	Benign	0.22	Tolerated	4.32	14	1	0	-2.5	30.03	219.8	-42.8	-0.1	0.0	-0.5	0.2								Uncertain	The methyl group of Ala301, located in a β hairpin loop linking two anti-parallel β sheet strands (res. Met289-Pro298, res. Thr305-Asn315), points outward from the β hairpin loop, and its backbone atoms do not participate in the loop formation in the WT simulations. In the variant simulations, the hydroxyl group of the Thr301 side chain also mostly points outward; however, the guanidinium group of Arg299 is moved away from its central hairpin loop position.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.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.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.1042G>A	V348M (3D Viewer)		C2	Uncertain		1				-7.076	In-Between	0.546	Ambiguous	Likely Benign	0.191	Likely Benign	-1.19	Ambiguous	0.1	0.72	Ambiguous	-0.24	Likely Benign	0.76	Ambiguous	-1.62	Neutral	0.966	Probably Damaging	0.564	Possibly Damaging	1.58	Pathogenic	0.03	Affected	3.37	25	2	1	-2.3	32.06	253.8	-47.4	-0.3	0.1	0.2	0.1						X		Potentially Benign	The iso-propyl side chain of Val348, located in an anti-parallel β sheet strand (res. Gly341-Pro349), packs against multiple hydrophobic C2 domain residues (e.g., Leu353, Leu323, Leu402). In the variant simulations, the thioether side chain of Met348 can form similar interactions as valine due to its comparable hydrophobic profile. In fact, the thioether group of methionine can even stack favorably with the phenol ring of Tyr363 in the anti-parallel β sheet strand (res. Ala399-Ile411). Overall, the residue swap does not appear to cause negative effects on the protein structure based on the simulations.
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.1240A>G	M414V		GAP	Uncertain		1				-8.003	Likely Pathogenic	0.541	Ambiguous	Likely Benign	0.261	Likely Benign	1.81	Ambiguous	0.4	1.73	Ambiguous	1.77	Ambiguous	0.95	Ambiguous	-2.95	Deleterious	0.999	Probably Damaging	0.987	Probably Damaging	3.43	Benign	0.24	Tolerated			2	1	2.3	-32.06
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.1511A>G	K504R (3D Viewer)	Likely Benign	GAP	Uncertain		1	6-33438543-A-G	2	1.24e-6	-4.365	Likely Benign	0.088	Likely Benign	Likely Benign	0.238	Likely Benign	0.13	Likely Benign	0.1	0.51	Ambiguous	0.32	Likely Benign	0.94	Ambiguous	-2.16	Neutral	0.002	Benign	0.015	Benign	-1.41	Pathogenic	0.11	Tolerated	3.37	35	2	3	-0.6	28.01
c.1513T>C	Y505H (3D Viewer)	Likely Pathogenic	GAP	Likely Pathogenic		1				-11.383	Likely Pathogenic	0.982	Likely Pathogenic	Likely Pathogenic	0.646	Likely Pathogenic	2.91	Destabilizing	0.1	2.88	Destabilizing	2.90	Destabilizing	1.60	Destabilizing	-4.97	Deleterious	1.000	Probably Damaging	1.000	Probably Damaging	2.64	Benign	0.00	Affected	3.37	35	2	0	-1.9	-26.03
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.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.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.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.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.1678G>A	V560M (3D Viewer)		GAP	Uncertain		2	6-33440730-G-A	15	9.50e-6	-9.598	Likely Pathogenic	0.517	Ambiguous	Likely Benign	0.520	Likely Pathogenic	-0.33	Likely Benign	0.1	0.88	Ambiguous	0.28	Likely Benign	0.72	Ambiguous	-2.42	Neutral	0.999	Probably Damaging	0.863	Possibly Damaging	-1.25	Pathogenic	0.14	Tolerated	3.37	35	2	1	-2.3	32.06	234.9	-52.6	0.0	0.0	-0.1	0.1						X		Potentially Benign	Val560 is located on the surface at the end of an α-helix (res. Ala533-Val560). The iso-propyl group of Val560 favorably packs against Asp508 of the opposing α-helix (res. Gln503-Glu519). However, in the variant simulations, the bulkier thioether side chain of Met560 does not form equally favorable inter-helix interactions. Regardless, no negative structural effects are observed during the simulations.
c.169C>T	L57F	Likely Benign		Uncertain		2				-5.096	Likely Benign	0.459	Ambiguous	Likely Benign	0.051	Likely Benign										-0.78	Neutral	0.824	Possibly Damaging	0.879	Possibly Damaging	3.96	Benign	0.00	Affected	4.32	1	2	0	-1.0	34.02
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.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.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.1789T>C	F597L (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-10.173	Likely Pathogenic	0.998	Likely Pathogenic	Likely Pathogenic	0.929	Likely Pathogenic	0.74	Ambiguous	0.1	2.12	Destabilizing	1.43	Ambiguous	1.20	Destabilizing	-5.97	Deleterious	0.999	Probably Damaging	0.994	Probably Damaging	-2.06	Pathogenic	0.13	Tolerated			2	0	1.0	-34.02
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.1851G>T	E617D (3D Viewer)	Likely Benign	GAP	Uncertain		1				-1.349	Likely Benign	0.241	Likely Benign	Likely Benign	0.322	Likely Benign	0.12	Likely Benign	0.1	0.80	Ambiguous	0.46	Likely Benign	0.07	Likely Benign	-0.01	Neutral	0.994	Probably Damaging	0.979	Probably Damaging	-1.35	Pathogenic	0.88	Tolerated	3.37	35	2	3	0.0	-14.03
c.1873C>G	L625V	Likely Pathogenic	GAP	Uncertain		1				-11.319	Likely Pathogenic	0.833	Likely Pathogenic	Ambiguous	0.480	Likely Benign	1.80	Ambiguous	0.7	1.69	Ambiguous	1.75	Ambiguous	1.42	Destabilizing	-2.96	Deleterious	0.998	Probably Damaging	0.992	Probably Damaging	3.07	Benign	0.01	Affected			2	1	0.4	-14.03
c.187G>C	E63Q	Likely Benign		Uncertain		1				-4.038	Likely Benign	0.687	Likely Pathogenic	Likely Benign	0.078	Likely Benign										-0.85	Neutral	0.659	Possibly Damaging	0.775	Possibly Damaging	3.90	Benign	0.00	Affected	4.32	1	2	2	0.0	-0.98
c.1913A>G	K638R (3D Viewer)	Likely Benign	GAP	Uncertain		1				-2.700	Likely Benign	0.110	Likely Benign	Likely Benign	0.216	Likely Benign	0.09	Likely Benign	0.1	-0.04	Likely Benign	0.03	Likely Benign	0.53	Ambiguous	-2.55	Deleterious	0.649	Possibly Damaging	0.240	Benign	3.41	Benign	0.13	Tolerated	3.37	31	2	3	-0.6	28.01
c.1942T>C	F648L	Likely Pathogenic	GAP	Uncertain		1				-9.296	Likely Pathogenic	0.999	Likely Pathogenic	Likely Pathogenic	0.468	Likely Benign	2.71	Destabilizing	0.8	2.08	Destabilizing	2.40	Destabilizing	1.04	Destabilizing	-5.98	Deleterious	0.999	Probably Damaging	0.976	Probably Damaging	3.45	Benign	0.08	Tolerated			2	0	1.0	-34.02
c.194A>G	H65R	Likely Benign		Uncertain		1	6-33425802-A-G	1	6.20e-7	-1.980	Likely Benign	0.967	Likely Pathogenic	Likely Pathogenic	0.073	Likely Benign										-1.60	Neutral	0.462	Possibly Damaging	0.227	Benign	4.19	Benign	0.00	Affected	4.32	1	2	0	-1.3	19.05
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.1957C>G	L653V	Likely Benign	GAP	Uncertain		1				-7.050	In-Between	0.301	Likely Benign	Likely Benign	0.146	Likely Benign	3.28	Destabilizing	0.3	2.18	Destabilizing	2.73	Destabilizing	1.32	Destabilizing	-2.25	Neutral	0.227	Benign	0.039	Benign	3.28	Benign	0.08	Tolerated			2	1	0.4	-14.03
c.2050G>A	D684N (3D Viewer)	Likely Pathogenic	GAP	Uncertain		1				-13.155	Likely Pathogenic	0.985	Likely Pathogenic	Likely Pathogenic	0.382	Likely Benign	1.47	Ambiguous	0.8	1.76	Ambiguous	1.62	Ambiguous	0.37	Likely Benign	-4.99	Deleterious	0.999	Probably Damaging	0.746	Possibly Damaging	3.39	Benign	0.01	Affected			2	1	0.0	-0.98
c.2095G>A	V699M (3D Viewer)		GAP	Uncertain		2	6-33441354-G-A	8	4.96e-6	-8.869	Likely Pathogenic	0.484	Ambiguous	Likely Benign	0.276	Likely Benign	-0.58	Ambiguous	0.1	0.29	Likely Benign	-0.15	Likely Benign	0.96	Ambiguous	-2.18	Neutral	0.994	Probably Damaging	0.806	Possibly Damaging	3.37	Benign	0.03	Affected	3.47	10	2	1	-2.3	32.06	257.8	-47.2	0.0	0.0	0.9	0.1						X		Potentially Benign	The isopropyl side chain of Val699, located on an α-helix (res. Leu685-Gln702), packs against hydrophobic residues (e.g., Leu703, Leu696, Leu435, Leu439) in the inter-helix space. In the variant simulations, the thioether side chain of Met699 has similar physicochemical properties to Val699 in the WT, and thus, it is able to maintain similar interactions. Consequently, the mutation causes no apparent changes in the structure.
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.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.218G>A	R73K	Likely Benign		Uncertain		1	6-33425826-G-A	2	1.24e-6	-4.033	Likely Benign	0.151	Likely Benign	Likely Benign	0.077	Likely Benign										-0.46	Neutral	0.053	Benign	0.007	Benign	4.14	Benign	0.00	Affected	4.32	1	2	3	0.6	-28.01
c.2207G>A	R736H	Likely Benign		Uncertain		1	6-33441672-G-A	6	3.72e-6	-5.409	Likely Benign	0.067	Likely Benign	Likely Benign	0.029	Likely Benign										-0.12	Neutral	0.004	Benign	0.001	Benign	2.50	Benign	0.00	Affected	4.07	3	2	0	1.3	-19.05
c.2215G>C	E739Q	Likely Benign		Uncertain		1				-2.846	Likely Benign	0.161	Likely Benign	Likely Benign	0.071	Likely Benign										-1.06	Neutral	0.801	Possibly Damaging	0.339	Benign	2.57	Benign	0.00	Affected	4.32	2	2	2	0.0	-0.98
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.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.2218C>T	R740W			Uncertain		2	6-33441683-C-T	6	3.72e-6	-8.561	Likely Pathogenic	0.168	Likely Benign	Likely Benign	0.180	Likely Benign										-3.09	Deleterious	1.000	Probably Damaging	0.938	Probably Damaging	2.52	Benign	0.01	Affected	4.32	2	2	-3	3.6	30.03
c.2239G>C	V747L	Likely Benign		Uncertain		1	6-33441704-G-C	2	1.24e-6	-2.790	Likely Benign	0.096	Likely Benign	Likely Benign	0.047	Likely Benign										-0.52	Neutral	0.065	Benign	0.033	Benign	2.67	Benign	0.00	Affected	4.32	2	2	1	-0.4	14.03
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.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.2245C>T	R749W			Likely Benign		1	6-33441710-C-T	3	1.86e-6	-7.647	In-Between	0.338	Likely Benign	Likely Benign	0.173	Likely Benign										-2.62	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	2.59	Benign	0.00	Affected	4.32	2	2	-3	3.6	30.03
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.2305C>T	L769F	Likely Benign		Uncertain		1				-5.044	Likely Benign	0.146	Likely Benign	Likely Benign	0.060	Likely Benign										-0.89	Neutral	0.925	Possibly Damaging	0.510	Possibly Damaging	3.94	Benign	0.02	Affected			2	0	-1.0	34.02
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.2354G>A	R785H		SH3-binding motif	Uncertain		2	6-33442906-G-A	4	2.50e-6	-4.782	Likely Benign	0.388	Ambiguous	Likely Benign	0.129	Likely Benign										-2.61	Deleterious	0.999	Probably Damaging	0.947	Probably Damaging	2.25	Pathogenic	0.01	Affected	3.64	6	2	0	1.3	-19.05
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.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.2444G>A	R815H		SH3-binding motif	Likely Benign		2	6-33442996-G-A	24	1.49e-5	-7.474	In-Between	0.553	Ambiguous	Likely Benign	0.157	Likely Benign										-1.81	Neutral	1.000	Probably Damaging	0.998	Probably Damaging	2.61	Benign	0.02	Affected	4.32	4	2	0	1.3	-19.05																10.1016/j.ajhg.2020.11.011
c.2503C>A	L835M	Likely Benign		Benign		1				-4.153	Likely Benign	0.121	Likely Benign	Likely Benign	0.068	Likely Benign										-0.45	Neutral	0.999	Probably Damaging	0.977	Probably Damaging	2.67	Benign	0.12	Tolerated	3.77	5	2	4	-1.9	18.03
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.2561G>A	R854H	Likely Benign		Uncertain		1	6-33443113-G-A	4	2.48e-6	-3.686	Likely Benign	0.094	Likely Benign	Likely Benign	0.183	Likely Benign										-1.38	Neutral	0.997	Probably Damaging	0.899	Possibly Damaging	4.07	Benign	0.04	Affected	3.88	3	2	0	1.3	-19.05
c.2596G>T	V866L	Likely Benign		Uncertain		1	6-33443148-G-T	1	6.20e-7	-3.352	Likely Benign	0.148	Likely Benign	Likely Benign	0.046	Likely Benign										-0.97	Neutral	0.217	Benign	0.229	Benign	2.71	Benign	0.21	Tolerated	3.82	4	2	1	-0.4	14.03
c.2608C>G	L870V	Likely Benign		Uncertain		1				-4.123	Likely Benign	0.300	Likely Benign	Likely Benign	0.111	Likely Benign										-1.19	Neutral	0.997	Probably Damaging	0.992	Probably Damaging	2.64	Benign	0.12	Tolerated	3.88	3	2	1	0.4	-14.03
c.2669G>A	R890H	Likely Benign		Benign		1	6-33443221-G-A	19	1.18e-5	-3.600	Likely Benign	0.198	Likely Benign	Likely Benign	0.056	Likely Benign										-1.29	Neutral	0.254	Benign	0.134	Benign	3.97	Benign	0.15	Tolerated	4.32	4	2	0	1.3	-19.05
c.2710A>G	M904V	Likely Benign		Likely Benign		2	6-33443262-A-G	77	4.78e-5	-2.907	Likely Benign	0.112	Likely Benign	Likely Benign	0.058	Likely Benign										-0.33	Neutral	0.039	Benign	0.023	Benign	2.80	Benign	0.10	Tolerated	3.77	5	2	1	2.3	-32.06
c.2714G>A	R905H	Likely Benign		Uncertain		1	6-33443266-G-A	8	4.96e-6	-4.182	Likely Benign	0.457	Ambiguous	Likely Benign	0.192	Likely Benign										-1.11	Neutral	1.000	Probably Damaging	0.991	Probably Damaging	2.59	Benign	0.09	Tolerated	3.77	5	2	0	1.3	-19.05
c.2852A>G	H951R	Likely Benign		Likely Pathogenic		1				-4.964	Likely Benign	0.125	Likely Benign	Likely Benign	0.185	Likely Benign										-1.08	Neutral	0.048	Benign	0.029	Benign	5.46	Benign	0.24	Tolerated	3.77	5	2	0	-1.3	19.05
c.2888A>G	H963R	Likely Benign		Uncertain		1	6-33443440-A-G	8	4.96e-6	-8.952	Likely Pathogenic	0.169	Likely Benign	Likely Benign	0.081	Likely Benign										-1.28	Neutral	0.001	Benign	0.003	Benign	4.15	Benign	0.24	Tolerated	3.77	5	2	0	-1.3	19.05
c.28C>T	R10W	Likely Benign		Uncertain		1	6-33420292-C-T	2	1.30e-6	-5.707	Likely Benign	0.503	Ambiguous	Likely Benign	0.236	Likely Benign										-0.31	Neutral	0.964	Probably Damaging	0.190	Benign	4.10	Benign	0.00	Affected	4.32	1	2	-3	3.6	30.03
c.2928T>G	F976L	Likely Benign		Uncertain		1				-2.432	Likely Benign	0.825	Likely Pathogenic	Ambiguous	0.212	Likely Benign										-0.87	Neutral	0.264	Benign	0.102	Benign	4.20	Benign	0.53	Tolerated	4.32	2	2	0	1.0	-34.02
c.2935T>C	F979L	Likely Benign		Uncertain		1				-2.341	Likely Benign	0.870	Likely Pathogenic	Ambiguous	0.228	Likely Benign										-1.00	Neutral	0.625	Possibly Damaging	0.430	Benign	4.22	Benign	0.73	Tolerated	4.32	2	2	0	1.0	-34.02
c.2962C>T	L988F	Likely Benign		Uncertain		1	6-33443514-C-T	1	6.20e-7	-4.368	Likely Benign	0.356	Ambiguous	Likely Benign	0.135	Likely Benign										-1.70	Neutral	0.977	Probably Damaging	0.900	Possibly Damaging	2.69	Benign	0.00	Affected	4.32	2	2	0	-1.0	34.02
c.3022G>A	D1008N	Likely Benign		Likely Benign		1	6-33443574-G-A	3	1.86e-6	-4.045	Likely Benign	0.714	Likely Pathogenic	Likely Benign	0.128	Likely Benign										-2.15	Neutral	0.999	Probably Damaging	0.997	Probably Damaging	2.75	Benign	0.01	Affected	3.77	5	2	1	0.0	-0.98
c.3048C>A	D1016E	Likely Benign		Likely Benign		1	6-33443600-C-A	2	1.24e-6	-3.422	Likely Benign	0.216	Likely Benign	Likely Benign	0.017	Likely Benign										-0.37	Neutral	0.008	Benign	0.028	Benign	2.64	Benign	0.65	Tolerated	3.77	5	2	3	0.0	14.03
c.304T>G	L102V	Likely Benign		Uncertain		1	6-33432169-T-G	1	6.20e-7	-4.316	Likely Benign	0.068	Likely Benign	Likely Benign	0.102	Likely Benign										0.32	Neutral	0.880	Possibly Damaging	0.899	Possibly Damaging	4.21	Benign	0.00	Affected	4.32	1	2	1	0.4	-14.03
c.3056G>A	R1019H	Likely Benign		Conflicting		2	6-33443608-G-A	67	4.15e-5	-4.610	Likely Benign	0.258	Likely Benign	Likely Benign	0.122	Likely Benign										-1.95	Neutral	0.995	Probably Damaging	0.845	Possibly Damaging	2.39	Pathogenic	0.01	Affected	3.77	5	2	0	1.3	-19.05
c.3308G>A	R1103H	Likely Benign		Benign/Likely benign		3	6-33443860-G-A	31	2.03e-5	-3.622	Likely Benign	0.156	Likely Benign	Likely Benign	0.116	Likely Benign										-1.97	Neutral	0.996	Probably Damaging	0.733	Possibly Damaging	2.49	Pathogenic	0.01	Affected	3.77	5	2	0	1.3	-19.05
c.3457C>T	R1153W	Likely Pathogenic		Uncertain		2	6-33444492-C-T	2	1.24e-6	-5.812	Likely Benign	0.994	Likely Pathogenic	Likely Pathogenic	0.317	Likely Benign										-5.88	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.46	Pathogenic	0.00	Affected	3.77	5	2	-3	3.6	30.03
c.3574C>G	L1192V	Likely Benign	Coiled-coil	Uncertain		1				-4.132	Likely Benign	0.471	Ambiguous	Likely Benign	0.041	Likely Benign										-0.89	Neutral	0.779	Possibly Damaging	0.527	Possibly Damaging	2.69	Benign	0.16	Tolerated			2	1	0.4	-14.03
c.3607C>T	H1203Y	Likely Benign	Coiled-coil	Uncertain		1	6-33446599-C-T	2	1.24e-6	-6.834	Likely Benign	0.149	Likely Benign	Likely Benign	0.233	Likely Benign										-1.52	Neutral	0.006	Benign	0.011	Benign	5.55	Benign	0.10	Tolerated	3.77	5	2	0	1.9	26.03
c.3640C>T	R1214W	Likely Pathogenic	Coiled-coil	Uncertain		1	6-33446632-C-T	2	1.24e-6	-8.799	Likely Pathogenic	0.710	Likely Pathogenic	Likely Benign	0.143	Likely Benign										-4.95	Deleterious	1.000	Probably Damaging	0.983	Probably Damaging	2.45	Pathogenic	0.00	Affected	3.77	5	2	-3	3.6	30.03
c.3661C>T	R1221W	Likely Pathogenic	Coiled-coil	Conflicting		3	6-33446653-C-T	1	6.20e-7	-10.938	Likely Pathogenic	0.651	Likely Pathogenic	Likely Benign	0.174	Likely Benign										-4.57	Deleterious	1.000	Probably Damaging	0.987	Probably Damaging	2.50	Benign	0.01	Affected	3.77	5	2	-3	3.6	30.03
c.379C>T	R127W			Uncertain		1				-4.776	Likely Benign	0.806	Likely Pathogenic	Ambiguous	0.118	Likely Benign										-2.98	Deleterious	0.989	Probably Damaging	0.420	Benign	3.88	Benign	0.00	Affected			2	-3	3.6	30.03
c.3906G>C	L1302F			Uncertain		1				-5.674	Likely Benign	0.148	Likely Benign	Likely Benign	0.211	Likely Benign										-2.70	Deleterious	0.960	Probably Damaging	0.657	Possibly Damaging	1.53	Pathogenic	0.00	Affected			2	0	-1.0	34.02
c.3923G>A	R1308H			Uncertain		1	6-33451797-G-A	3	1.86e-6	-3.586	Likely Benign	0.201	Likely Benign	Likely Benign	0.319	Likely Benign										-3.12	Deleterious	0.998	Probably Damaging	0.991	Probably Damaging	2.33	Pathogenic	0.00	Affected	3.77	5	2	0	1.3	-19.05
c.3943T>C	W1315R	Likely Benign		Uncertain		1				0.205	Likely Benign	0.660	Likely Pathogenic	Likely Benign	0.114	Likely Benign										1.31	Neutral	0.000	Benign	0.001	Benign	4.37	Benign	0.91	Tolerated	3.77	5	2	-3	-3.6	-30.03
c.3G>A	M1I	Likely Benign		Conflicting		3				-5.397	Likely Benign				0.227	Likely Benign										-0.17	Neutral	0.001	Benign	0.000	Benign	4.25	Benign	0.00	Affected	4.32	1	2	1	2.6	-18.03
c.4008G>C	E1336D	Likely Benign		Likely Benign		1				-3.344	Likely Benign	0.596	Likely Pathogenic	Likely Benign	0.062	Likely Benign										-1.92	Neutral	0.001	Benign	0.003	Benign	3.30	Benign	0.00	Affected	3.77	5	2	3	0.0	-14.03
c.406C>T	R136W	Likely Pathogenic		Uncertain		2				-10.453	Likely Pathogenic	0.989	Likely Pathogenic	Likely Pathogenic	0.237	Likely Benign										-4.71	Deleterious	0.965	Probably Damaging	0.416	Benign	3.45	Benign	0.00	Affected	3.61	5	2	-3	3.6	30.03
c.470G>A	R157H			Uncertain		1	6-33432767-G-A	1	6.20e-7	-10.235	Likely Pathogenic	0.604	Likely Pathogenic	Likely Benign	0.254	Likely Benign										-2.23	Neutral	0.999	Probably Damaging	0.987	Probably Damaging	3.80	Benign	0.00	Affected	3.74	4	2	0	1.3	-19.05
c.485G>A	R162H			Uncertain		1	6-33432782-G-A	2	1.24e-6	-9.730	Likely Pathogenic	0.480	Ambiguous	Likely Benign	0.167	Likely Benign										-1.13	Neutral	0.957	Probably Damaging	0.513	Possibly Damaging	4.03	Benign	0.12	Tolerated	3.74	4	2	0	1.3	-19.05
c.48G>A	M16I	Likely Benign		Uncertain		1	6-33420312-G-A	1	6.49e-7	-2.198	Likely Benign	0.722	Likely Pathogenic	Likely Benign	0.057	Likely Benign										-0.15	Neutral	0.000	Benign	0.000	Benign	4.28	Benign	0.00	Affected	4.32	1	2	1	2.6	-18.03
c.505G>A	D169N			Uncertain		1				-10.713	Likely Pathogenic	0.761	Likely Pathogenic	Likely Benign	0.110	Likely Benign										-2.04	Neutral	0.079	Benign	0.052	Benign	4.07	Benign	0.01	Affected	3.74	4	2	1	0.0	-0.98
c.508C>T	R170W	Likely Pathogenic		Uncertain		2				-11.660	Likely Pathogenic	0.978	Likely Pathogenic	Likely Pathogenic	0.241	Likely Benign										-4.28	Deleterious	0.999	Probably Damaging	0.849	Possibly Damaging	3.84	Benign	0.00	Affected	3.74	4	2	-3	3.6	30.03
c.514C>T	R172W	Likely Pathogenic		Uncertain		2	6-33435156-C-T	9	5.58e-6	-10.258	Likely Pathogenic	0.878	Likely Pathogenic	Ambiguous	0.228	Likely Benign										-3.61	Deleterious	0.997	Probably Damaging	0.803	Possibly Damaging	3.95	Benign	0.00	Affected	3.61	5	2	-3	3.6	30.03
c.558G>C	L186F	Likely Pathogenic		Uncertain		1				-11.861	Likely Pathogenic	0.993	Likely Pathogenic	Likely Pathogenic	0.132	Likely Benign										-3.03	Deleterious	0.009	Benign	0.012	Benign	3.50	Benign	0.00	Affected			2	0	-1.0	34.02
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.718G>A	D240N	Likely Pathogenic	PH	Uncertain		1				-12.942	Likely Pathogenic	0.755	Likely Pathogenic	Likely Benign	0.701	Likely Pathogenic	0.22	Likely Benign	0.9	0.47	Likely Benign	0.35	Likely Benign	0.37	Likely Benign	-4.37	Deleterious	0.993	Probably Damaging	0.984	Probably Damaging	5.88	Benign	0.01	Affected			2	1	0.0	-0.98
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.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.878G>A	R293H	Likely Pathogenic	C2	Uncertain		1				-13.009	Likely Pathogenic	0.973	Likely Pathogenic	Likely Pathogenic	0.438	Likely Benign	4.45	Destabilizing	2.3	2.12	Destabilizing	3.29	Destabilizing	0.32	Likely Benign	-4.60	Deleterious	1.000	Probably Damaging	0.998	Probably Damaging	1.45	Pathogenic	0.04	Affected			2	0	1.3	-19.05
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.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.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.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.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.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.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.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.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.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.103G>A	V35I	Likely Benign		Uncertain		1	6-33423512-G-A	5	3.10e-6	-3.764	Likely Benign	0.081	Likely Benign	Likely Benign	0.017	Likely Benign										-0.32	Neutral	0.672	Possibly Damaging	0.369	Benign	4.16	Benign	0.00	Affected	4.32	1	3	4	0.3	14.03
c.1417G>A	V473I (3D Viewer)		GAP	Uncertain		1	6-33438449-G-A	1	6.20e-7	-7.481	In-Between	0.418	Ambiguous	Likely Benign	0.203	Likely Benign	-0.12	Likely Benign	0.0	1.20	Ambiguous	0.54	Ambiguous	-0.06	Likely Benign	-0.91	Neutral	0.929	Possibly Damaging	0.917	Probably Damaging	3.74	Benign	0.18	Tolerated	3.37	34	3	4	0.3	14.03
c.1447A>G	I483V (3D Viewer)		GAP	Conflicting		2				-10.121	Likely Pathogenic	0.523	Ambiguous	Likely Benign	0.228	Likely Benign	1.00	Ambiguous	0.0	0.27	Likely Benign	0.64	Ambiguous	1.02	Destabilizing	-0.86	Neutral	0.914	Possibly Damaging	0.921	Probably Damaging	3.23	Benign	0.03	Affected	3.37	32	3	4	-0.3	-14.03
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.2195G>A	R732K	Likely Benign		Conflicting		2	6-33441660-G-A	4	2.48e-6	-5.278	Likely Benign	0.240	Likely Benign	Likely Benign	0.045	Likely Benign										-0.82	Neutral	0.973	Probably Damaging	0.943	Probably Damaging	2.69	Benign	0.21	Tolerated	3.59	7	3	2	0.6	-28.01
c.2217G>C	E739D	Likely Benign		Uncertain		1				-3.369	Likely Benign	0.062	Likely Benign	Likely Benign	0.097	Likely Benign										-0.49	Neutral	0.002	Benign	0.005	Benign	2.59	Benign	0.00	Affected			3	2	0.0	-14.03
c.2408A>G	K803R	Likely Benign	SH3-binding motif	Uncertain		1				-2.281	Likely Benign	0.097	Likely Benign	Likely Benign	0.018	Likely Benign										-1.52	Neutral	0.103	Benign	0.038	Benign	2.38	Pathogenic	0.00	Affected	3.77	5	3	2	-0.6	28.01
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.2493G>C	E831D	Likely Benign		Uncertain		1	6-33443045-G-C	1	6.19e-7	-3.055	Likely Benign	0.063	Likely Benign	Likely Benign	0.073	Likely Benign										1.23	Neutral	0.002	Benign	0.002	Benign	2.64	Benign	0.77	Tolerated	3.77	5	3	2	0.0	-14.03
c.2724G>C	Q908H	Likely Benign		Conflicting		4	6-33443276-G-C	1	6.20e-7	-4.658	Likely Benign	0.311	Likely Benign	Likely Benign	0.112	Likely Benign										-0.74	Neutral	0.996	Probably Damaging	0.995	Probably Damaging	2.58	Benign	0.05	Affected	3.77	5	3	0	0.3	9.01
c.2835T>A	H945Q	Likely Benign		Conflicting		2	6-33443387-T-A	3	1.86e-6	-5.248	Likely Benign	0.091	Likely Benign	Likely Benign	0.343	Likely Benign										-0.36	Neutral	0.995	Probably Damaging	0.939	Probably Damaging	5.03	Benign	0.06	Tolerated	4.32	4	3	0	-0.3	-9.01
c.291G>T	E97D	Likely Benign		Uncertain		3	6-33425899-G-T			-3.239	Likely Benign	0.077	Likely Benign	Likely Benign	0.081	Likely Benign										-0.49	Neutral	0.880	Possibly Damaging	0.636	Possibly Damaging	4.12	Benign	0.00	Affected	4.32	1	3	2	0.0	-14.03
c.2998A>G	I1000V	Likely Benign		Uncertain		2				-4.102	Likely Benign	0.098	Likely Benign	Likely Benign	0.086	Likely Benign										-0.20	Neutral	0.437	Benign	0.170	Benign	2.76	Benign	0.81	Tolerated	4.32	4	3	4	-0.3	-14.03
c.303C>A	H101Q	Likely Benign		Uncertain		1	6-33432168-C-A	1	6.20e-7	-2.827	Likely Benign	0.124	Likely Benign	Likely Benign	0.147	Likely Benign										-0.37	Neutral	0.824	Possibly Damaging	0.880	Possibly Damaging	4.24	Benign	0.00	Affected	4.32	1	3	0	-0.3	-9.01
c.3192G>C	Q1064H	Likely Benign		Uncertain		1				-4.576	Likely Benign	0.162	Likely Benign	Likely Benign	0.063	Likely Benign										-0.66	Neutral	0.938	Possibly Damaging	0.596	Possibly Damaging	4.15	Benign	0.05	Affected			3	0	0.3	9.01
c.3209G>A	R1070K	Likely Benign		Conflicting		2				-5.093	Likely Benign	0.326	Likely Benign	Likely Benign	0.104	Likely Benign										-1.42	Neutral	0.049	Benign	0.048	Benign	3.86	Benign	0.09	Tolerated	3.77	5	3	2	0.6	-28.01
c.323A>G	K108R	Likely Benign		Uncertain		1	6-33432188-A-G	6	3.72e-6	-2.892	Likely Benign	0.148	Likely Benign	Likely Benign	0.184	Likely Benign										0.37	Neutral	0.993	Probably Damaging	0.956	Probably Damaging	4.22	Benign	1.00	Tolerated	3.61	5	3	2	-0.6	28.01
c.3567G>C	E1189D	Likely Benign	Coiled-coil	Likely Benign		1	6-33444602-G-C	3	1.86e-6	-3.582	Likely Benign	0.461	Ambiguous	Likely Benign	0.359	Likely Benign										-1.42	Neutral	0.992	Probably Damaging	0.989	Probably Damaging	5.30	Benign	0.25	Tolerated	3.82	4	3	2	0.0	-14.03
c.3846G>C	E1282D	Likely Benign		Uncertain		1	6-33447894-G-C	1	6.44e-7	-3.879	Likely Benign	0.074	Likely Benign	Likely Benign	0.104	Likely Benign										-1.26	Neutral	0.112	Benign	0.036	Benign	2.70	Benign	0.39	Tolerated	3.77	5	3	2	0.0	-14.03
c.3858A>T	E1286D	Likely Benign		Conflicting		4	6-33447906-A-T	143	9.22e-5	-4.010	Likely Benign	0.081	Likely Benign	Likely Benign	0.036	Likely Benign										1.02	Neutral	0.001	Benign	0.004	Benign	2.96	Benign	1.00	Tolerated	3.77	5	3	2	0.0	-14.03																10.1016/j.ajhg.2020.11.011
c.453C>A	D151E	Likely Benign		Uncertain		1				-5.662	Likely Benign	0.886	Likely Pathogenic	Ambiguous	0.142	Likely Benign										-2.02	Neutral	0.984	Probably Damaging	0.967	Probably Damaging	3.99	Benign	0.11	Tolerated	3.61	5	3	2	0.0	14.03
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.70G>A	V24I	Likely Benign		Uncertain		1	6-33423479-G-A	9	5.58e-6	-3.701	Likely Benign	0.137	Likely Benign	Likely Benign	0.069	Likely Benign										-0.25	Neutral	0.043	Benign	0.031	Benign	3.96	Benign	0.00	Affected	4.32	1	3	4	0.3	14.03
c.958G>A	V320I (3D Viewer)	Likely Benign	C2	Uncertain		1				-5.220	Likely Benign	0.111	Likely Benign	Likely Benign	0.027	Likely Benign	-0.27	Likely Benign	0.2	0.66	Ambiguous	0.20	Likely Benign	0.01	Likely Benign	-0.21	Neutral	0.198	Benign	0.114	Benign	1.77	Pathogenic	0.45	Tolerated	3.38	23	3	4	0.3	14.03
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.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.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.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.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.1354G>A	V452I (3D Viewer)		GAP	Uncertain		1				-8.985	Likely Pathogenic	0.361	Ambiguous	Likely Benign	0.218	Likely Benign	-0.08	Likely Benign	0.1	0.51	Ambiguous	0.22	Likely Benign	0.25	Likely Benign	-0.99	Neutral	0.947	Possibly Damaging	0.851	Possibly Damaging	3.26	Benign	0.05	Affected			4	3	0.3	14.03
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.1663G>A	V555I (3D Viewer)	Likely Benign	GAP	Uncertain		1				-4.544	Likely Benign	0.084	Likely Benign	Likely Benign	0.253	Likely Benign	-0.82	Ambiguous	0.0	-0.41	Likely Benign	-0.62	Ambiguous	-0.55	Ambiguous	0.45	Neutral	0.002	Benign	0.002	Benign	-1.26	Pathogenic	1.00	Tolerated			4	3	0.3	14.03
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.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.2275A>C	M759L	Likely Benign		Uncertain		1	6-33441740-A-C	2	1.24e-6	-2.431	Likely Benign	0.093	Likely Benign	Likely Benign	0.048	Likely Benign										-0.53	Neutral	0.002	Benign	0.005	Benign	2.84	Benign	1.00	Tolerated	3.99	5	4	2	1.9	-18.03
c.2299A>G	I767V	Likely Benign		Uncertain		1				-2.791	Likely Benign	0.064	Likely Benign	Likely Benign	0.096	Likely Benign										0.10	Neutral	0.072	Benign	0.029	Benign	4.21	Benign	1.00	Tolerated	3.64	6	4	3	-0.3	-14.03
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.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.256G>A	V86I	Likely Benign		Uncertain		1				-4.726	Likely Benign	0.338	Likely Benign	Likely Benign	0.076	Likely Benign										-0.31	Neutral	0.267	Benign	0.097	Benign	3.94	Benign	0.00	Affected	4.32	1	4	3	0.3	14.03
c.2578G>A	V860I	Likely Benign		Benign		1	6-33443130-G-A	21	1.30e-5	-4.516	Likely Benign	0.095	Likely Benign	Likely Benign	0.039	Likely Benign										-0.42	Neutral	0.009	Benign	0.006	Benign	4.24	Benign	0.00	Affected	3.77	5	4	3	0.3	14.03
c.2596G>A	V866I	Likely Benign		Conflicting		3	6-33443148-G-A	5	3.10e-6	-4.652	Likely Benign	0.118	Likely Benign	Likely Benign	0.059	Likely Benign										-0.39	Neutral	0.957	Probably Damaging	0.541	Possibly Damaging	2.69	Benign	0.27	Tolerated	3.82	4	4	3	0.3	14.03
c.2695A>G	I899V	Likely Benign		Benign		1	6-33443247-A-G	6	3.72e-6	-2.569	Likely Benign	0.074	Likely Benign	Likely Benign	0.040	Likely Benign										0.09	Neutral	0.220	Benign	0.078	Benign	2.75	Benign	0.92	Tolerated	4.32	4	4	3	-0.3	-14.03
c.3397A>G	I1133V	Likely Benign		Benign		1	6-33443949-A-G	22	1.48e-5	-3.362	Likely Benign	0.067	Likely Benign	Likely Benign	0.180	Likely Benign										0.06	Neutral	0.007	Benign	0.007	Benign	5.47	Benign	0.58	Tolerated	4.32	3	4	3	-0.3	-14.03																10.1016/j.ajhg.2020.11.011
c.3442A>T	M1148L	Likely Benign		Uncertain		1				-1.777	Likely Benign	0.093	Likely Benign	Likely Benign	0.068	Likely Benign										-1.13	Neutral	0.016	Benign	0.016	Benign	2.62	Benign	0.00	Affected	4.32	2	4	2	1.9	-18.03
c.3502A>G	I1168V	Likely Benign		Uncertain		1				-3.263	Likely Benign	0.524	Ambiguous	Likely Benign	0.363	Likely Benign										-0.14	Neutral	0.876	Possibly Damaging	0.643	Possibly Damaging	5.47	Benign	0.84	Tolerated	3.88	3	4	3	-0.3	-14.03
c.3721C>A	L1241M		Coiled-coil	Uncertain		1				-5.881	Likely Benign	0.782	Likely Pathogenic	Likely Benign	0.167	Likely Benign										-1.43	Neutral	1.000	Probably Damaging	0.999	Probably Damaging	1.65	Pathogenic	0.00	Affected			4	2	-1.9	18.03
c.37A>G	I13V	Likely Benign		Uncertain		1				-2.497	Likely Benign	0.105	Likely Benign	Likely Benign	0.110	Likely Benign										0.01	Neutral	0.000	Benign	0.000	Benign	4.25	Benign	0.00	Affected			4	3	-0.3	-14.03
c.2420A>T	Y807F	Likely Benign	SH3-binding motif	Uncertain		1				-3.667	Likely Benign	0.073	Likely Benign	Likely Benign	0.057	Likely Benign										0.14	Neutral	0.012	Benign	0.022	Benign	2.92	Benign	0.98	Tolerated	3.77	5	7	3	4.1	-16.00