KCNH2 Variant Q1113E Detail

We estimate the penetrance of LQTS for KCNH2 Q1113E is 8%. We are unaware of any observations of this variant in individuals. Q1113E is not present in gnomAD. We have tested the trafficking efficiency of this variant, 56% of WT with a standard error of 34%; 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. Q1113E 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 Q1113E around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.545 0.431 4 0.567 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: - 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.

Q1113E 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
1113 0
1112 4
1114 4
1111 5 V1111F,
1115 5 M1115T,
1110 7 Q1110P,
1116 7 A1116V,
1109 8
1117 8 C1117fsX,
1108 8 L1108V,
1118 8
1107 9 S1107L,
1119 9 E1119V, E1119Q,
1106 10
1120 10
1105 11 L1105S,
1121 11
1104 11 T1104I,
1122 11 P1122L, P1122fsX, P1122R,
1103 12 L1103P,
1123 12 G1123R, G1123R,
1102 13
1124 13
1101 13 P1101fsX,
1125 13 P1125A, P1125X,
1100 14
1126 14 E1126fsX,
1099 14 P1099L,
1127 14
1098 15 S1098R, S1098R, S1098R,
1128 15