SCN5A Variant H1849Q Detail

We estimate the penetrance of LQTS for SCN5A H1849Q around 38% and the Brugada syndrome penetrance around 16%. SCN5A H1849Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. H1849Q is not present in gnomAD. H1849Q has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a 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 H1849Q around 38% (1/10) and the Brugada syndrome penetrance around 16% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.88 15 50
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 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.

H1849Q has 48 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 4 C1850S,
1855 11
1803 15
1814 12
1794 11
1849 0 H1849R,
1856 12
1806 8 p.Thr1806SerfsX27,
1853 7 I1853V,
1795 11 Y1795N, Y1795H, Y1795C, p.Y1795_E1796insD,
1813 14
1801 14
1838 14
1802 11
1504 12 K1504E,
1811 13 Y1811X, Y1811N,
1843 9
1851 5 M1851V, M1851I,
1501 12 p.L1501_K1505del, L1501V,
1857 12
1507 14 p.Q1507_P1509del,
1505 11 p.K1505_Q1507del, K1505N,
1858 14
1808 5
1804 14
1807 5 c.5420dupA,
1798 9 W1798X,
1854 9
1797 15 I1797V,
1848 6
1817 12
1846 13
1839 12 D1839G,
1799 15
1844 12
1791 15
1852 5 D1852V,
1502 12 G1502S, G1502A,
1805 11
1842 10 M1842T, M1842V, M1842L,
1810 13
1809 8 I1809M,
1506 10 P1506T, P1506S,
1841 8
1503 13 S1503Y,
1847 9 R1847H, R1847C,
1845 13 G1845R,
1840 10