KCNH2 Variant G1085E Detail

We estimate the penetrance of LQTS for KCNH2 G1085E is 8%. This variant was found in a total of 1 carriers in 0 papers or gnomAD (version 4), 0 had LQTS. G1085E is present in 1 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 64% of WT with a standard error of 7%; 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. G1085E 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 G1085E around 8% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.126 0.0 0 0.131 3
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: - 1 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.

G1085E 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
1085 0 G1085X,
1084 4 P1084R, P1084L, P1084X,
1086 4 P1086fsX, P1086X,
1083 5 T1083fsX, T1083A,
1087 5 G1087X,
1082 7
1088 7
1081 8
1089 8 T1089I, T1089A,
1080 8
1090 8 S1090F,
1079 9 S1079N,
1091 9
1078 10 Y1078C,
1092 10 S1092F,
1077 11 A1077D, A1077T,
1093 11 P1093R, P1093L,
1076 11
1094 11 L1094M,
1075 12 P1075L,
1095 12
1074 13
1096 13
1073 13 L1073P,
1097 13 V1097I,
1072 14 T1072S, T1072M,
1098 14 S1098R, S1098R, S1098R,
1071 14 M1071V,
1099 14 P1099L,
1070 15 Q1070P, Q1070X,
1100 15