SCN5A Variant K1505N Detail

We estimate the penetrance of LQTS for SCN5A K1505N around 63% and the Brugada syndrome penetrance around 12%. SCN5A K1505N was found in a total of 2 carriers in 2 papers and/or in gnomAD: 0 had Brugada syndrome, 2 had LQTS. K1505N is not present in gnomAD. K1505N has been functionally characterized in 2 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 (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A K1505N around 63% (4/12) and the Brugada syndrome penetrance around 12% (1/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.6 0.68 -1.06 0.728 15 62
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
22360817 2012 1 1 0 0
19716085 2009 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 2 0 2 0 -
VARIANT FEATURES ALONE: - 15 12 2 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.

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)
19716085 2009
22360817 2012

K1505N has 31 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 9 C1850S,
1794 12
1849 11 H1849R,
1806 11 p.Thr1806SerfsX27,
1853 14 I1853V,
1795 8 Y1795H, Y1795N, p.Y1795_E1796insD, Y1795C,
1802 13
1504 6 K1504E,
1851 9 M1851I, M1851V,
1501 11 L1501V, p.L1501_K1505del,
1507 8 p.Q1507_P1509del,
1505 0 p.K1505_Q1507del, K1505N,
1509 13 P1509T,
1808 13
1804 15
1807 8 c.5420dupA,
1798 11 W1798X,
1854 12
1499 13
1796 13
1799 12
1788 13 c.5361_5364delTGAG,
1500 12 p.K1500del,
1791 12
1852 14 D1852V,
1792 12 D1792V, D1792Y, D1792N,
1508 9
1502 9 G1502S, G1502A,
1805 10
1506 5 P1506S, P1506T,
1503 7 S1503Y,