SCN5A Variant V223G Detail

We estimate the penetrance of LQTS for SCN5A V223G around 16% and the Brugada syndrome penetrance around 35%. SCN5A V223G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V223G is not present in gnomAD. V223G has been functionally characterized in 0 papers. This residue is located in a Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (3 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A V223G around 16% (0/10) and the Brugada syndrome penetrance around 35% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.984 48 17
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance Density is our previously published method to calculate the average BrS/LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT3 BrS1 Other Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 12 0 3 - -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

V223G has 68 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
891 14 I891T, I891N,
888 14
848 10 I848F,
223 0 V223L,
856 7 V856L,
862 15
859 9
149 12
147 12
193 14 W193X, W193R,
164 13 F164L,
195 14
228 11 K228R,
138 14 M138I,
227 8 L227P,
143 13
887 13
142 12
197 12
229 11
216 13 S216X, S216L,
851 7 c.2552_2553dupGT, c.2550_2551dupGT, F851L, p.F851CfsX19,
221 7
196 10
852 5
854 9 c.2559delT,
222 6 R222L, R222X, R222Q,
224 4 L224F,
845 14 c.2533delG,
857 10 G857D,
150 15
881 15
849 11
226 6 A226G, A226V,
921 15
922 15 V922I,
860 11 p.L860fsx89,
858 10 M858L,
144 8
217 11
918 14
855 6
230 13 I230V, I230M, I230T,
199 12 S199T,
148 7
165 14
884 12
204 11 A204T, c.611+1G>A, c.611+3_611+4dupAA, A204V,
146 12 V146M, V146A,
847 13
203 11
168 13
202 14 I202T,
141 10 I141N, I141V,
853 9
161 13 E161Q, E161K,
201 12
219 9 c.656_657insATTCA, p.R219HfsX11, R219C, R219H,
225 8 R225Q, R225W,
151 12
218 11
207 14
850 11 c.2549_2550insTG, V850M,
200 8
145 8
140 13
861 14 p.F861WfsX90, c.2582_2583delTT,
220 7 T220I,