SCN5A Variant T1858I Detail

We estimate the penetrance of LQTS for SCN5A T1858I around 5% and the Brugada syndrome penetrance around 39%. SCN5A T1858I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1858I is not present in gnomAD. T1858I has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 T1858I around 5% (0/10) and the Brugada syndrome penetrance around 39% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.93 55 2
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 12 0 3 - -
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.

T1858I has 70 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 12 C1850S,
1855 6
1814 15
1785 9
1794 10
1849 14 H1849R,
1856 6
1853 9 I1853V,
1795 13 Y1795H, Y1795N, Y1795C, p.Y1795_E1796insD,
1834 14 S1834R,
1818 12
1880 14 M1880V,
1866 12
1824 8 P1824A,
1838 10
1504 12 K1504E,
1491 15 Q1491H,
1863 9
1851 11 M1851V, M1851I,
1501 7 L1501V, p.L1501_K1505del,
1860 8 c.5577_5578dupAA,
1857 6
1874 14
1862 6
1493 13 K1493X, K1493R, p.K1493del,
1867 14
1858 0
1865 11
1787 11 S1787N,
1835 13 L1835F,
1786 7 L1786Q, L1786R, c.5356_5357delCT,
1861 5 V1861I, V1861F,
1495 14 Y1495S,
1864 10
1821 11
1798 14 W1798X,
1826 13 R1826H, R1826C,
1496 12
1854 6
1825 7 L1825P,
1797 15 I1797V,
1793 14 M1793K,
1781 13 E1781D, E1781G,
1789 14
1499 13
1817 13
1877 14 E1877K,
1784 11 E1784X, E1784K,
1827 11
1498 8 M1498V, M1498T, M1498R,
1839 12 D1839G,
1788 13 c.5361_5364delTGAG,
1500 10 p.K1500del,
1859 6
1876 13
1791 8
1868 14
1852 11 D1852V,
1792 13 D1792Y, D1792N, D1792V,
1823 13 E1823K, p.E1823HfsX10,
1502 12 G1502A, G1502S,
1783 14
1837 15
1497 7
1790 10 p.D1790del, D1790N, D1790G,
1494 9
1503 13 S1503Y,
1840 12
1822 12 c.5464-5467delTCTG, c.5464_5467delTCTG,
1782 14