SCN5A Variant V856G Detail

We estimate the penetrance of LQTS for SCN5A V856G around 7% and the Brugada syndrome penetrance around 17%. SCN5A V856G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V856G is not present in gnomAD. V856G has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 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 V856G around 7% (0/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.985 15 5
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 14 0 1 - -
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.

V856G 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 10 I891N, I891T,
880 14
888 12
848 13 I848F,
223 7 V223L,
856 0 V856L,
890 12 I890T,
919 11
862 10
859 6
894 14 I894M,
149 13
863 13
925 13 I925F,
227 12 L227P,
887 9
864 13
886 14 H886Q, H886P,
216 11 S216X, S216L,
851 9 c.2552_2553dupGT, c.2550_2551dupGT, F851L, p.F851CfsX19,
221 7
196 15
852 6
854 6 c.2559delT,
222 10 R222Q, R222L, R222X,
224 9 L224F,
857 4 G857D,
902 14
882 13
881 9
849 11
226 12 A226V, A226G,
921 11
922 11 V922I,
860 6 p.L860fsx89,
920 14
889 15
858 7 M858L,
144 14
217 10
918 8
855 5
917 13 L917R, L917V,
865 14
913 14
916 15
148 10
884 11
906 13
910 14 S910L,
885 15
847 14
203 13
152 14 D152N,
853 6
219 10 R219H, p.R219HfsX11, R219C, c.656_657insATTCA,
225 14 R225Q, R225W,
151 13
218 12
883 13
915 11 C915R,
215 14 p.L215CfsX10,
850 10 c.2549_2550insTG, V850M,
914 10
200 13
145 13
861 8 p.F861WfsX90, c.2582_2583delTT,
220 5 T220I,