KCNH2 Variant T1133A Detail

We estimate the penetrance of LQTS for KCNH2 T1133A is 8%. We are unaware of any observations of this variant in individuals. T1133A is not present in gnomAD. T1133A has not been functionally characterized. This residue is located in a Non_Hotspot region for LQT2. In silico predictions, functional data (if available), and location in structure are equivalent to observing 0 individuals with LQT2 and 10 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 T1133A around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.317 0.0 0 0.331 4
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 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 LQT2 Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 -
VARIANT FEATURES ALONE: - 10 10 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.

T1133A 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. NOTE: some residues appear multiple times at different distances since the functional KV11.1 channel (protein product of KCNH2/hERG) is a homotetramer and occasionally the same residue from multiple subunits is present within the 15A window. 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
1133 0
1132 4 P1132A,
1134 4 R1134X,
1131 5 G1131V,
1135 5 R1135C, R1135H,
1130 7
1136 7 L1136I,
1129 8
1137 8
1128 8
1138 8
1127 9
1139 9 P1139L,
1126 10 E1126fsX,
1140 10
1125 11 P1125A, P1125X,
1141 11
1124 11
1142 11
1123 12 G1123R, G1123R,
1143 12
1122 13 P1122R, P1122fsX, P1122L,
1144 13 A1144T,
1121 13
1145 13
1120 14
1146 14 T1146S, T1146A, T1146I, T1146S,
1119 14 E1119Q, E1119V,
1147 14
1118 15
1148 15