SCN5A Variant S835A Detail

We estimate the penetrance of LQTS for SCN5A S835A around 9% and the Brugada syndrome penetrance around 21%. SCN5A S835A was found in a total of 3 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S835A is present in 3 alleles in gnomAD. S835A has been functionally characterized in 0 papers. This residue is located in a Non_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 (2 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 S835A around 9% (0/13) and the Brugada syndrome penetrance around 21% (2/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.97 0.895 0.47 0.906 38 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: - 3 3 0 0 -
VARIANT FEATURES ALONE: - 15 13 0 2 - -
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.

S835A has 46 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
939 13 L939F,
937 8
839 5 L839P,
842 10
943 13 S943N,
1455 14
1461 14 T1461S,
836 4 V836M,
826 15 N826D,
234 12 P234S,
934 10
933 13
935 14 L935P,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
944 14
845 15 c.2533delG,
830 10
833 5 G833R,
940 10 S940N,
831 7
420 13
938 9
235 12 c.703+1G>A, G235R, c.704-1G>C,
840 8
942 9
843 11 T843A,
1456 12
1459 15 c.4376_4379delTCTT,
834 5 N834D,
827 13
1460 10 F1460L,
837 5
239 13 I239V, I239V ,
416 13 Y416C,
841 9 N841K, p.N841TfsX2,
941 7 S941F, S941N,
936 12
238 12
233 14
838 5
844 13 L844RfsX3,
829 10
832 5
835 0 S835A, S835L,
828 10 L828V,
1463 15 N1463Y,