SCN5A Variant M1144K Detail

We estimate the penetrance of LQTS for SCN5A M1144K around 3% and the Brugada syndrome penetrance around 13%. SCN5A M1144K was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M1144K is not present in gnomAD. M1144K has been functionally characterized in 0 papers. This residue is located in a Mild_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 M1144K around 3% (0/10) and the Brugada syndrome penetrance around 13% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.555 12 1
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: - 0 0 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.

M1144K 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
1129 15 G1129S,
1130 14 E1130K,
1131 14 c.3390-1G>A, T1131I, c.3391-1G>A, T1131S,
1132 13 P1132S,
1133 13
1134 12 D1134N, D1134E,
1135 11 S1135I,
1136 11 C1136Y,
1137 10
1138 9
1139 8
1140 8 S1140T,
1141 7
1142 5
1143 4
1144 0
1145 4
1146 5
1147 7 T1147I, T1147S, T1147N,
1148 8 A1148S, A1148T,
1149 8
1150 9
1151 10
1152 11 E1152X,
1153 11 Q1153H,
1154 12 I1154N,
1155 13 P1155S,
1156 13 D1156G,
1157 14
1158 14 G1158S,
1159 15