SCN5A Variant L1927H Detail

We estimate the penetrance of LQTS for SCN5A L1927H around 4% and the Brugada syndrome penetrance around 10%. SCN5A L1927H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1927H is not present in gnomAD. L1927H 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 (0 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 L1927H around 4% (0/10) and the Brugada syndrome penetrance around 10% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.866 3 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 15 0 0 - -
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.

L1927H 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
1912 15
1913 14 R1913S, R1913H, R1913C,
1914 14 R1914G,
1915 13 H1915P, H1915Q, H1915N, H1915Y,
1916 13
1917 12
1918 11
1919 11 R1919H, R1919C,
1920 10 S1920C,
1921 9
1922 8 K1922N, K1922R,
1923 8 H1923Y, H1923D,
1924 7 A1924T,
1925 5 S1925F, p.S1925CfsX20,
1926 4
1927 0 L1927P,
1928 4 F1928V,
1929 5 R1929H, R1929C,
1930 7 Q1930H,
1931 8
1932 8 A1932V,
1933 9 G1933A, G1933D, G1933V,
1934 10
1935 11 G1935S,
1936 11
1937 12 S1937A,
1938 13 E1938K, E1938X,
1939 13 p.E1939_E1943del,
1940 14
1941 14
1942 15 P1942S, P1942H,