SCN5A Variant M1906T Detail

We estimate the penetrance of LQTS for SCN5A M1906T around 1% and the Brugada syndrome penetrance around 2%. SCN5A M1906T was found in a total of 4 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1906T is present in 4 alleles in gnomAD. M1906T 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 M1906T around 1% (0/14) and the Brugada syndrome penetrance around 2% (0/14).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
1.84 0 0.1 0.27 1 3
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: - 4 4 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.

M1906T 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
1891 15
1892 14
1893 14 c.5676delC,
1894 13
1895 13 T1895I,
1896 12 L1896P, p.L1896PfsX47,
1897 11 R1897Q, R1897W, R1897Y,
1898 11 R1898C, R1898H,
1899 10
1900 9
1901 8 E1901Q, E1901K,
1902 8 E1902A,
1903 7 V1903M,
1904 5 S1904L,
1905 4
1906 0 M1906T, M1906V,
1907 4
1908 5 I1908V,
1909 7 Q1909R,
1910 8 R1910K,
1911 8
1912 9
1913 10 R1913H, R1913C, R1913S,
1914 11 R1914G,
1915 11 H1915Y, H1915P, H1915Q, H1915N,
1916 12
1917 13
1918 13
1919 14 R1919H, R1919C,
1920 14 S1920C,
1921 15