SCN5A Variant V1202M Detail

We estimate the penetrance of LQTS for SCN5A V1202M around 3% and the Brugada syndrome penetrance around 8%. SCN5A V1202M was found in a total of 3 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V1202M is present in 3 alleles in gnomAD. V1202M has been functionally characterized in 1 papers. This residue is located in a Non_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 V1202M around 3% (0/13) and the Brugada syndrome penetrance around 8% (1/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.94 1 -1.31 0.816 7 6
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
24529773 2014 1 0 0 1 SUNDS
LITERATURE, COHORT, AND GNOMAD: - 3 3 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.

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)
24529773 2014

V1202M 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
1187 15 P1187Q,
1188 14
1189 14 K1189T,
1190 13 V1190F,
1191 13 W1191X,
1192 12 W1192X,
1193 11 R1193Q, R1193W,
1194 11 L1194M,
1195 10 R1195H, R1195S,
1196 9
1197 8
1198 8
1199 7 Y1199S,
1200 5 p.H1200PfsX41, H1200Y, H1200R,
1201 4 I1201M,
1202 0 V1202M,
1203 4
1204 5
1205 7
1206 8
1207 8
1208 9 E1208X, E1208K,
1209 10 T1209R,
1210 11 F1210S,
1211 11
1212 12 p.I1212del,
1213 13
1214 13 M1214T,
1215 14 I1215V,
1216 14 L1216V,
1217 15