SCN5A Variant T1197I Detail

We estimate the penetrance of LQTS for SCN5A T1197I around 21% and the Brugada syndrome penetrance around 14%. SCN5A T1197I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1197I is not present in gnomAD. T1197I has been functionally characterized in 0 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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A T1197I around 21% (1/10) and the Brugada syndrome penetrance around 14% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.84 10 25
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 13 1 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.

T1197I 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
1182 15
1183 14 T1183I,
1184 14
1185 13 c.3553_3554delCA,
1186 13 A1186T,
1187 12 P1187Q,
1188 11
1189 11 K1189T,
1190 10 V1190F,
1191 9 W1191X,
1192 8 W1192X,
1193 8 R1193Q, R1193W,
1194 7 L1194M,
1195 5 R1195H, R1195S,
1196 4
1197 0
1198 4
1199 5 Y1199S,
1200 7 H1200Y, H1200R, p.H1200PfsX41,
1201 8 I1201M,
1202 8 V1202M,
1203 9
1204 10
1205 11
1206 11
1207 12
1208 13 E1208X, E1208K,
1209 13 T1209R,
1210 14 F1210S,
1211 14
1212 15 p.I1212del,