SCN5A Variant G857D Detail

We estimate the penetrance of LQTS for SCN5A G857D around 4% and the Brugada syndrome penetrance around 13%. SCN5A G857D was found in a total of 3 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G857D is present in 3 alleles in gnomAD. G857D 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 G857D around 4% (0/13) and the Brugada syndrome penetrance around 13% (1/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.93 1 -4.19 0.982 13 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: - 3 3 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.

G857D has 71 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 I891T, I891N,
880 11
888 11
848 15 I848F,
223 10 V223L,
856 4 V856L,
890 9 I890T,
919 9
862 7
867 15 E867Q, E867X, E867K,
859 6
894 12 I894M,
149 13
863 11
887 7
864 10
886 11 H886P, H886Q,
216 11 S216X, S216L,
851 10 c.2550_2551dupGT, F851L, p.F851CfsX19, c.2552_2553dupGT,
221 10
909 13
852 9
854 5 c.2559delT,
222 13 R222L, R222Q, R222X,
224 12 L224F,
857 0 G857D,
902 12
882 10
892 14 F892I,
881 5
849 13
226 15 A226G, A226V,
893 15 R893C, R893H,
921 12
922 11 V922I,
860 5 p.L860fsx89,
911 14 G911E,
920 14
889 12
858 5 M858L,
217 11
918 8
855 6
917 13 L917V, L917R,
865 10
913 13
916 14
148 12
884 10
906 10
866 14 S866P, S866L,
910 11 S910L,
885 13
903 13 p.M903CfsX29,
152 13 D152N,
853 8
219 11 c.656_657insATTCA, R219C, R219H, p.R219HfsX11,
877 15
151 13
879 14 W879R,
218 14
883 10
905 14
915 9 C915R,
215 14 p.L215CfsX10,
850 11 V850M, c.2549_2550insTG,
914 9
145 15
861 5 c.2582_2583delTT, p.F861WfsX90,
220 8 T220I,
907 14