SCN5A Variant G1502A Detail

We estimate the penetrance of LQTS for SCN5A G1502A around 18% and the Brugada syndrome penetrance around 15%. SCN5A G1502A was found in a total of 2 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G1502A is present in 2 alleles in gnomAD. G1502A has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Mild_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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A G1502A around 18% (1/12) and the Brugada syndrome penetrance around 15% (1/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.52 0.947 -0.26 0.903 18 27
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 13 1 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.

G1502A has 37 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
1850 10 C1850S,
1855 10
1794 13
1849 12 H1849R,
1856 13
1853 13 I1853V,
1795 11 Y1795H, Y1795C, Y1795N, p.Y1795_E1796insD,
1492 15
1504 6 K1504E,
1851 7 M1851V, M1851I,
1501 5 L1501V, p.L1501_K1505del,
1857 15
1507 15 p.Q1507_P1509del,
1505 9 K1505N, p.K1505_Q1507del,
1858 12
1787 15 S1787N,
1786 13 c.5356_5357delCT, L1786Q, L1786R,
1807 13 c.5420dupA,
1495 10 Y1495S,
1798 15 W1798X,
1496 11
1854 9
1499 6
1498 7 M1498T, M1498R, M1498V,
1788 12 c.5361_5364delTGAG,
1500 7 p.K1500del,
1859 15
1876 13
1791 10
1852 12 D1852V,
1792 13 D1792Y, D1792V, D1792N,
1502 0 G1502A, G1502S,
1497 9
1790 15 D1790G, D1790N, p.D1790del,
1494 12
1506 12 P1506T, P1506S,
1503 4 S1503Y,