SCN5A Variant E1231K Detail

We estimate the penetrance of LQTS for SCN5A E1231K around 16% and the Brugada syndrome penetrance around 12%. SCN5A E1231K was found in a total of 4 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. E1231K is present in 3 alleles in gnomAD. E1231K has been functionally characterized in 1 papers. This residue is located in a Mild_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 (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 E1231K around 16% (1/14) and the Brugada syndrome penetrance around 12% (1/14).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.06 0.037 0.8 0.549 19 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
15840476 2005 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 4 3 1 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.

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)
15840476 2005

E1231K has 22 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
1231 0 E1231K,
1226 11
1233 8 K1233E,
1695 12 Q1695X,
1237 13 V1237F,
1228 6 Y1228F, Y1228H, Y1228C,
1223 15 c.3667delG,
1681 13 c.5040_5042delTTAinsC, Y1681F,
1224 12
1697 14
1230 6 E1230K,
1227 8
1225 12 G1225K, E1225K,
1234 10
1229 7
1239 14 L1239P,
1232 6 R1232W, R1232Q,
331 15
1238 14
1236 10 K1236R, K1236N,
1235 9
1696 12