SCN5A Variant I1797L Detail

We estimate the penetrance of LQTS for SCN5A I1797L around 20% and the Brugada syndrome penetrance around 10%. SCN5A I1797L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1797L is not present in gnomAD. I1797L 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 I1797L around 20% (1/10) and the Brugada syndrome penetrance around 10% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.757 4 24
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.

I1797L has 56 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,
1803 12
1814 12
1794 6
1849 15 H1849R,
1806 15 p.Thr1806SerfsX27,
1853 12 I1853V,
1795 8 Y1795H, Y1795C, Y1795N, p.Y1795_E1796insD,
1828 14 A1828T, A1828S,
1813 11
1818 9
1801 6
1824 13 P1824A,
1802 10
1820 6 A1820V, A1820T,
1504 13 K1504E,
1857 12
1507 10 p.Q1507_P1509del,
1858 15
1509 12 P1509T,
1829 15
1787 15 S1787N,
1804 15
1819 10 D1819N,
1786 15 c.5356_5357delCT, L1786Q, L1786R,
1807 14 c.5420dupA,
1526 15 T1526P,
1815 12
1821 6
1798 7 W1798X,
1826 11 R1826C, R1826H,
1854 12
1825 10 L1825P,
1797 0 I1797V,
1800 5
1793 6 M1793K,
1789 12
1848 15
1817 6
1827 13
1796 5
1799 7
1788 14 c.5361_5364delTGAG,
1638 12 R1638X, R1638Q,
1791 11
1792 10 D1792Y, D1792V, D1792N,
1823 13 E1823K, p.E1823HfsX10,
1508 15
1816 10 D1816N, D1816E, c.5445_5446insT,
1805 13
1810 15
1528 15
1790 11 D1790G, D1790N, p.D1790del,
1809 11 I1809M,
1506 12 P1506T, P1506S,
1822 8 c.5464-5467delTCTG, c.5464_5467delTCTG,