SCN5A Variant M1842L Detail

We estimate the penetrance of LQTS for SCN5A M1842L around 4% and the Brugada syndrome penetrance around 3%. SCN5A M1842L was found in a total of 2 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1842L is present in 2 alleles in gnomAD. M1842L 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 M1842L around 4% (0/12) and the Brugada syndrome penetrance around 3% (0/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.8 0.017 2.43 0.612 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: - 2 2 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.

M1842L has 32 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
1852 9 D1852V,
1850 13 C1850S,
1811 7 Y1811N, Y1811X,
1843 5
1814 10
1851 14 M1851V, M1851I,
1849 10 H1849R,
1856 14
1857 15
1842 0 M1842V, M1842L, M1842T,
1806 14 p.Thr1806SerfsX27,
1853 11 I1853V,
1837 14
1848 6
1812 11 S1812L, S1812X,
1808 10
1810 10
1836 11 I1836T,
1813 12
1846 5
1835 12 L1835F,
1839 10 D1839G,
1809 10 I1809M,
1844 7
1807 14 c.5420dupA,
1841 5
1838 13
1847 7 R1847C, R1847H,
1845 7 G1845R,
1832 13 Q1832E,
1840 7
1815 14