SCN5A Variant V918A Detail

We estimate the penetrance of LQTS for SCN5A V918A around 5% and the Brugada syndrome penetrance around 35%. SCN5A V918A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V918A is not present in gnomAD. V918A has been functionally characterized in 0 papers. This residue is located in a 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 (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 V918A around 5% (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 0.932 48 2
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.

V918A has 62 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 9 I891N, I891T,
888 15
223 14 V223L,
856 8 V856L,
890 11 I890T,
901 15 S901L, E901K,
919 4
862 13
363 13
859 13
895 13 L895F,
894 10 I894M,
926 12
928 14 L928P,
925 10 I925F,
904 13 W904X,
366 14
887 12
864 14
851 15 p.F851CfsX19, c.2550_2551dupGT, c.2552_2553dupGT, F851L,
897 14 G897R, G897E,
221 12
924 10 V924I,
909 14
927 14 N927K, N927S,
852 11
854 10 c.2559delT,
224 14 L224F,
857 8 G857D,
902 10
881 11
849 12
898 15
893 14 R893H, R893C,
921 5
922 6 V922I,
860 8 p.L860fsx89,
911 13 G911E,
920 6
900 13
858 13 M858L,
217 14
918 0
855 12
917 5 L917V, L917R,
865 14
913 9
916 7
912 12 Q912R,
906 9
910 12 S910L,
903 9 p.M903CfsX29,
853 7
923 10
905 14
915 6 C915R,
899 10
850 12 V850M, c.2549_2550insTG,
914 6
861 8 c.2582_2583delTT, p.F861WfsX90,
220 12 T220I,
907 10