SCN5A Variant I1827N Detail

We estimate the penetrance of LQTS for SCN5A I1827N around 15% and the Brugada syndrome penetrance around 10%. SCN5A I1827N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1827N is not present in gnomAD. I1827N 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 (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A I1827N around 15% (0/10) 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 0.927 3 16
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 15 0 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.

I1827N has 52 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
1855 14
1814 9
1794 12
1856 10
1853 11 I1853V,
1828 4 A1828S, A1828T,
1834 7 S1834R,
1813 13
1818 4
1833 11 I1833M,
1801 14
1824 9 P1824A,
1838 9
1832 10 Q1832E,
1820 8 A1820V, A1820T,
1811 13 Y1811X, Y1811N,
1863 12
1860 7 c.5577_5578dupAA,
1857 7
1862 14
1812 14 S1812L, S1812X,
1858 11
1829 8
1865 15
1835 7 L1835F,
1819 6 D1819N,
1786 15 L1786Q, c.5356_5357delCT, L1786R,
1861 10 V1861I, V1861F,
1864 10
1821 7
1815 8
1798 14 W1798X,
1826 6 R1826H, R1826C,
1854 13
1825 7 L1825P,
1797 13 I1797V,
1793 14 M1793K,
1848 14
1817 8
1827 0
1839 15 D1839G,
1859 13
1823 9 E1823K, p.E1823HfsX10,
1816 10 D1816E, c.5445_5446insT, D1816N,
1837 11
1831 6
1836 12 I1836T,
1790 14 D1790N, D1790G, p.D1790del,
1809 14 I1809M,
1830 9
1840 12
1822 9 c.5464-5467delTCTG, c.5464_5467delTCTG,