KCNH2 Variant G1143E Detail

We estimate the penetrance of LQTS for KCNH2 G1143E is 8%. We are unaware of any observations of this variant in individuals. G1143E is not present in gnomAD. We have tested the trafficking efficiency of this variant, 92% of WT with a standard error of 9%; in our analysis we used SE < 20% as 'high quality'. Approximately below 50% of WT is considered PS3 moderate and below 30% is PS3 strong. G1143E 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 G1143E around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.947 0.916 -2 0.536 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 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.

G1143E 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
1143 0
1142 4
1144 4 A1144T,
1141 5
1145 5
1140 7
1146 7 T1146S, T1146A, T1146I, T1146S,
1139 8 P1139L,
1147 8
1138 8
1148 8
1137 9
1149 9
1136 10 L1136I,
1150 10 L1150R, L1150M, L1150P,
1135 11 R1135C, R1135H,
1151 11 H1151Q, H1151X, H1151Q,
1134 11 R1134X,
1152 11
1133 12
1153 12 H1153Y, H1153P,
1132 13 P1132A,
1154 13
1131 13 G1131V,
1155 13 S1155L,
1130 14
1156 14
1129 14
1157 14 P1157L,
1128 15
1158 15