SCN5A Variant L1921F Detail

We estimate the penetrance of LQTS for SCN5A L1921F around 2% and the Brugada syndrome penetrance around 11%. SCN5A L1921F was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1921F is not present in gnomAD. L1921F 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 L1921F around 2% (0/10) and the Brugada syndrome penetrance around 11% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.243 11 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 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.

L1921F 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
1906 15 M1906T, M1906V,
1907 14
1908 14 I1908V,
1909 13 Q1909R,
1910 13 R1910K,
1911 12
1912 11
1913 11 R1913C, R1913H, R1913S,
1914 10 R1914G,
1915 9 H1915N, H1915Q, H1915P, H1915Y,
1916 8
1917 8
1918 7
1919 5 R1919C, R1919H,
1920 4 S1920C,
1921 0
1922 4 K1922R, K1922N,
1923 5 H1923Y, H1923D,
1924 7 A1924T,
1925 8 p.S1925CfsX20, S1925F,
1926 8
1927 9 L1927P,
1928 10 F1928V,
1929 11 R1929H, R1929C,
1930 11 Q1930H,
1931 12
1932 13 A1932V,
1933 13 G1933V, G1933D, G1933A,
1934 14
1935 14 G1935S,
1936 15