SCN5A Variant Q1874E Detail

We estimate the penetrance of LQTS for SCN5A Q1874E around 4% and the Brugada syndrome penetrance around 13%. SCN5A Q1874E was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q1874E is not present in gnomAD. Q1874E 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 Q1874E around 4% (0/10) and the Brugada syndrome penetrance around 13% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.726 11 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.

Q1874E has 34 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
1855 12
1875 6 p.M1875dup, M1875T, M1875K,
1872 5 K1872N,
1878 7
1491 10 Q1491H,
1871 10
1870 9 A1870T,
1863 12
1856 15
1874 0
1862 11
1493 15 K1493R, K1493X, p.K1493del,
1867 11
1858 14
1873 5 I1873V,
1865 15
1879 9
1881 12
1877 5 E1877K,
1486 13 F1486L, p.F1486del,
1488 14 T1488R,
1882 13
1497 14
1490 13
1784 14 E1784X, E1784K,
1498 12 M1498T, M1498V, M1498R,
1880 10 M1880V,
1866 12
1494 9
1495 14 Y1495S,
1859 10
1869 7
1876 7
1868 10