SCN5A Variant c.5356_5357delCT Detail

We estimate the penetrance of LQTS for SCN5A c.5356_5357delCT around 18% and the Brugada syndrome penetrance around 49%. SCN5A c.5356_5357delCT was found in a total of 5 carriers in 3 papers and/or in gnomAD: 5 had Brugada syndrome, 0 had LQTS. c.5356_5357delCT is not present in gnomAD. c.5356_5357delCT has been functionally characterized in 3 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (2 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 c.5356_5357delCT around 18% (1/15) and the Brugada syndrome penetrance around 49% (7/15).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 27 48
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
16643399 2006 1 0 1 0
28781330 2017 3 0 3 0
20129283 2010 2 0 2 0
LITERATURE, COHORT, AND GNOMAD: - 5 0 0 5 -
VARIANT FEATURES ALONE: - 15 12 1 2 - -
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)
16643399 2006
28781330 2017
20129283 2010

c.5356_5357delCT has 64 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 12
1785 5
1794 11
1856 12
1778 10
1853 14 I1853V,
1795 13 Y1795N, Y1795C, p.Y1795_E1796insD, Y1795H,
1652 15 M1652R, M1652T,
1777 12 V1777M, V1777L,
1866 13
1824 7 P1824A,
1492 13
1504 12 K1504E,
1641 12
1491 14 Q1491H,
1863 12
1851 15 M1851I, M1851V,
1501 9 p.L1501_K1505del, L1501V,
1860 12 c.5577_5578dupAA,
1857 11
1862 8
1779 12 T1779M,
1493 9 p.K1493del, K1493R, K1493X,
1858 7
1865 11
1787 4 S1787N,
1786 0 L1786R, L1786Q, c.5356_5357delCT,
1648 12
1861 7 V1861I, V1861F,
1495 13 Y1495S,
1649 15 A1649V,
1864 12
1821 12
1644 14 R1644L, R1644C, R1644H,
1826 13 R1826H, R1826C,
1496 10
1854 10
1825 8 L1825P,
1797 15 I1797V,
1793 11 M1793K,
1781 7 E1781G, E1781D,
1789 9
1499 13
1645 12 T1645M,
1784 8 E1784X, E1784K,
1827 15
1498 11 M1498R, M1498T, M1498V,
1796 15
1780 12 E1780G,
1788 8 c.5361_5364delTGAG,
1500 7 p.K1500del,
1859 12
1791 6
1792 10 D1792N, D1792V, D1792Y,
1823 11 E1823K, p.E1823HfsX10,
1502 13 G1502S, G1502A,
1783 9
1497 7
1490 14
1790 5 D1790N, p.D1790del, D1790G,
1494 11
1503 13 S1503Y,
1822 10 c.5464_5467delTCTG, c.5464-5467delTCTG,
1782 8