SCN5A Variant L1917M Detail

We estimate the penetrance of LQTS for SCN5A L1917M around 3% and the Brugada syndrome penetrance around 10%. SCN5A L1917M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1917M is not present in gnomAD. L1917M has been functionally characterized in 0 papers. This residue is located in a Non_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 L1917M around 3% (0/10) and the Brugada syndrome penetrance around 10% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.572 6 1
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.

L1917M has 31 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
1902 15 E1902A,
1903 14 V1903M,
1904 14 S1904L,
1905 13
1906 13 M1906T, M1906V,
1907 12
1908 11 I1908V,
1909 11 Q1909R,
1910 10 R1910K,
1911 9
1912 8
1913 8 R1913H, R1913C, R1913S,
1914 7 R1914G,
1915 5 H1915Y, H1915P, H1915Q, H1915N,
1916 4
1917 0
1918 4
1919 5 R1919H, R1919C,
1920 7 S1920C,
1921 8
1922 8 K1922N, K1922R,
1923 9 H1923Y, H1923D,
1924 10 A1924T,
1925 11 S1925F, p.S1925CfsX20,
1926 11
1927 12 L1927P,
1928 13 F1928V,
1929 13 R1929H, R1929C,
1930 14 Q1930H,
1931 14
1932 15 A1932V,