SCN5A Variant I1154T Detail

We estimate the penetrance of LQTS for SCN5A I1154T around 3% and the Brugada syndrome penetrance around 7%. SCN5A I1154T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1154T is not present in gnomAD. I1154T has been functionally characterized in 0 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 (0 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 I1154T around 3% (0/10) and the Brugada syndrome penetrance around 7% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.529 1 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 15 0 0 - -
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.

I1154T 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
1139 15
1140 14 S1140T,
1141 14
1142 13
1143 13
1144 12
1145 11
1146 11
1147 10 T1147I, T1147S, T1147N,
1148 9 A1148S, A1148T,
1149 8
1150 8
1151 7
1152 5 E1152X,
1153 4 Q1153H,
1154 0 I1154N,
1155 4 P1155S,
1156 5 D1156G,
1157 7
1158 8 G1158S,
1159 8
1160 9
1161 10 c.3480delT,
1162 11
1163 11 D1163G, D1163E, D1163Y,
1164 12 P1164T,
1165 13 p.E1165RfsX6, E1165D, E1165Q,
1166 13 D1166N,
1167 14 C1167Y,
1168 14 F1168L,
1169 15 T1169I,