SCN5A Variant C1850S Detail

We estimate the penetrance of LQTS for SCN5A C1850S around 14% and the Brugada syndrome penetrance around 42%. SCN5A C1850S was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. C1850S is not present in gnomAD. C1850S has been functionally characterized in 1 papers. This residue is located in a 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 (3 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 C1850S around 14% (0/11) and the Brugada syndrome penetrance around 42% (4/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-9.23 0.947 -2.23 0.973 47 12
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
18252757 2008 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 12 0 3 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
18252757 2008 HEK 38 1.4 -11.6

C1850S has 62 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 0 C1850S,
1855 10
1803 14
1814 11
1794 8
1849 4 H1849R,
1856 10
1806 9 p.Thr1806SerfsX27,
1853 6 I1853V,
1795 7 Y1795N, Y1795C, p.Y1795_E1796insD, Y1795H,
1813 13
1818 13
1801 12
1838 14
1802 10
1820 15 A1820V, A1820T,
1504 9 K1504E,
1811 14 Y1811X, Y1811N,
1843 12
1851 4 M1851V, M1851I,
1501 9 p.L1501_K1505del, L1501V,
1857 10
1507 11 p.Q1507_P1509del,
1505 9 K1505N, p.K1505_Q1507del,
1858 12
1509 15 P1509T,
1808 7
1835 15 L1835F,
1804 14
1807 6 c.5420dupA,
1821 13
1798 6 W1798X,
1854 6
1825 13 L1825P,
1797 12 I1797V,
1800 14
1793 14 M1793K,
1848 7
1817 10
1846 15
1498 14 M1498R, M1498T, M1498V,
1839 13 D1839G,
1796 13
1799 12
1500 14 p.K1500del,
1859 15
1791 11
1852 6 D1852V,
1792 13 D1792N, D1792V, D1792Y,
1508 15
1502 10 G1502S, G1502A,
1805 10
1842 13 M1842V, M1842L, M1842T,
1810 13
1497 15
1790 15 D1790G, D1790N, p.D1790del,
1809 8 I1809M,
1506 8 P1506S, P1506T,
1841 11
1503 11 S1503Y,
1847 11 R1847C, R1847H,
1840 11