SCN5A Variant V855G Detail

We estimate the penetrance of LQTS for SCN5A V855G around 11% and the Brugada syndrome penetrance around 30%. SCN5A V855G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V855G is not present in gnomAD. V855G has been functionally characterized in 0 papers. This residue is located in a Mild_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 V855G around 11% (0/10) and the Brugada syndrome penetrance around 30% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.969 39 11
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.

V855G has 69 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 10 I891T, I891N,
880 14
888 10
848 11 I848F,
223 6 V223L,
856 5 V856L,
890 11 I890T,
919 13
862 11
859 7
894 15 I894M,
153 15
149 9
147 12
863 14
227 12 L227P,
143 14
887 8
142 14
156 15 W156R, W156X,
886 12 H886Q, H886P,
229 14
216 13 S216L, S216X,
851 6 c.2552_2553dupGT, p.F851CfsX19, F851L, c.2550_2551dupGT,
221 10
852 6
854 4 c.2559delT,
222 9 R222Q, R222L, R222X,
224 10 L224F,
857 6 G857D,
150 12
882 12
892 14 F892I,
881 9
849 11
226 10 A226V, A226G,
921 15
922 13 V922I,
860 9 p.L860fsx89,
889 13
858 5 M858L,
144 11
217 12
918 12
855 0
865 14
148 6
884 7
885 11
146 11 V146M, V146A,
847 12
203 15
846 14 L846R,
152 11 D152N,
141 14 I141V, I141N,
853 8
161 15 E161Q, E161K,
219 10 R219C, c.656_657insATTCA, p.R219HfsX11, R219H,
225 13 R225Q, R225W,
151 9
218 14
883 10
915 15 C915R,
850 9 V850M, c.2549_2550insTG,
914 14
200 14
145 9
861 10 p.F861WfsX90, c.2582_2583delTT,
220 8 T220I,