SCN5A Variant A1820V Detail

We estimate the penetrance of LQTS for SCN5A A1820V around 4% and the Brugada syndrome penetrance around 10%. SCN5A A1820V was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A1820V is present in 1 alleles in gnomAD. A1820V has been functionally characterized in 0 papers. This residue is located in a Non_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 A1820V around 4% (0/11) and the Brugada syndrome penetrance around 10% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.76 0.991 -1.12 0.749 6 4
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: - 1 1 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.

A1820V has 44 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 15 C1850S,
1814 10
1794 9
1853 13 I1853V,
1795 13 p.Y1795_E1796insD, Y1795N, Y1795H, Y1795C,
1828 9 A1828T, A1828S,
1834 15 S1834R,
1813 11
1818 5
1801 8
1824 12 P1824A,
1802 14
1820 0 A1820T, A1820V,
1860 14 c.5577_5578dupAA,
1857 11
1812 14 S1812X, S1812L,
1829 9
1835 13 L1835F,
1819 4 D1819N,
1861 15 V1861F, V1861I,
1821 4
1815 9
1798 11 W1798X,
1826 6 R1826H, R1826C,
1854 14
1825 9 L1825P,
1797 6 I1797V,
1800 9
1793 9 M1793K,
1789 14
1817 6
1827 8
1796 11
1799 12
1638 14 R1638Q, R1638X,
1791 14
1792 14 D1792Y, D1792V, D1792N,
1823 10 E1823K, p.E1823HfsX10,
1816 7 c.5445_5446insT, D1816E, D1816N,
1831 11
1790 12 D1790N, D1790G, p.D1790del,
1809 13 I1809M,
1830 13
1822 7 c.5464_5467delTCTG, c.5464-5467delTCTG,