SCN5A Variant M1793T Detail

We estimate the penetrance of LQTS for SCN5A M1793T around 31% and the Brugada syndrome penetrance around 9%. SCN5A M1793T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1793T is not present in gnomAD. M1793T has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 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 M1793T around 31% (1/10) and the Brugada syndrome penetrance around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.809 3 40
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 1 0 - -
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.

M1793T has 51 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 14 C1850S,
1794 7
1853 14 I1853V,
1795 8 Y1795H, p.Y1795_E1796insD, Y1795C, Y1795N,
1635 14
1818 12
1801 12
1824 11 P1824A,
1802 15
1820 9 A1820V, A1820T,
1504 12 K1504E,
1641 10
1501 15 p.L1501_K1505del, L1501V,
1857 13
1639 12 G1639A,
1507 11 p.Q1507_P1509del,
1858 14
1787 10 S1787N,
1819 13 D1819N,
1786 11 L1786Q, c.5356_5357delCT, L1786R,
1648 14
1861 14 V1861I, V1861F,
1821 7
1644 11 R1644H, R1644C, R1644L,
1640 14
1798 11 W1798X,
1826 10 R1826H, R1826C,
1854 12
1825 9 L1825P,
1797 6 I1797V,
1800 10
1793 0 M1793K,
1789 6
1817 10
1645 13 T1645M,
1827 14
1796 5
1799 10
1788 10 c.5361_5364delTGAG,
1638 8 R1638Q, R1638X,
1500 14 p.K1500del,
1791 8
1637 13
1792 6 D1792Y, D1792N, D1792V,
1636 14
1823 11 E1823K, p.E1823HfsX10,
1816 15 D1816E, c.5445_5446insT, D1816N,
1528 15
1790 6 p.D1790del, D1790N, D1790G,
1506 13 P1506T, P1506S,
1822 6 c.5464_5467delTCTG, c.5464-5467delTCTG,