SCN5A Variant L876Q Detail

We estimate the penetrance of LQTS for SCN5A L876Q around 4% and the Brugada syndrome penetrance around 42%. SCN5A L876Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L876Q is not present in gnomAD. L876Q 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 (4 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 L876Q around 4% (0/10) and the Brugada syndrome penetrance around 42% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.931 61 0
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 11 0 4 - -
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.

L876Q has 41 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
880 6
890 13 I890T,
901 14 E901K, S901L,
870 10
862 11
867 12 E867X, E867Q, E867K,
1426 13
1444 14 L1444I,
1440 8 W1440X,
863 13
1442 15 Y1442N, Y1442C,
887 13
864 11
886 10 H886Q, H886P,
871 9
909 11
876 0
868 10 L868X, c.2602delC,
902 13
882 8
881 10
889 14
858 14 M858L,
872 12 D872N,
865 7
1439 15 Q1439R, Q1439H,
906 13
866 8 S866L, S866P,
874 7 G874D,
910 14 S910L,
878 9 R878L, R878C, R878H,
1441 10 E1441Q,
877 4
879 10 W879R,
869 8 R869S,
883 11
905 10
875 4
908 12
873 11 S873A,
861 14 p.F861WfsX90, c.2582_2583delTT,