SCN5A Variant T1806I Detail

We estimate the penetrance of LQTS for SCN5A T1806I around 6% and the Brugada syndrome penetrance around 18%. SCN5A T1806I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1806I is not present in gnomAD. T1806I 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 T1806I around 6% (0/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.92 18 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: - 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.

T1806I has 39 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 13 D1852V,
1850 9 C1850S,
1798 8 W1798X,
1508 11
1843 11
1803 8
1854 15
1814 15
1794 14
1851 12 M1851I, M1851V,
1849 8 H1849R,
1797 15 I1797V,
1805 4
1800 14
1507 11 p.Q1507_P1509del,
1842 14 M1842V, M1842T, M1842L,
1806 0 p.Thr1806SerfsX27,
1853 13 I1853V,
1795 12 Y1795H, p.Y1795_E1796insD, Y1795C, Y1795N,
1848 11
1505 11 p.K1505_Q1507del, K1505N,
1817 14
1509 10 P1509T,
1808 5
1810 11
1813 13
1846 14
1804 6
1809 9 I1809M,
1801 12
1799 11
1844 13
1807 5 c.5420dupA,
1506 8 P1506T, P1506S,
1847 8 R1847C, R1847H,
1511 14
1845 12 G1845R,
1802 6
1504 15 K1504E,