KCNH2 Variant L1127H Detail

We estimate the penetrance of LQTS for KCNH2 L1127H is 8%. We are unaware of any observations of this variant in individuals. L1127H is not present in gnomAD. L1127H 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 L1127H around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.348 0.997 -3 0.602 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.

L1127H 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
1127 0
1126 4 E1126fsX,
1128 4
1125 5 P1125A, P1125X,
1129 5
1124 7
1130 7
1123 8 G1123R, G1123R,
1131 8 G1131V,
1122 8 P1122R, P1122fsX, P1122L,
1132 8 P1132A,
1121 9
1133 9
1120 10
1134 10 R1134X,
1119 11 E1119Q, E1119V,
1135 11 R1135C, R1135H,
1118 11
1136 11 L1136I,
1117 12 C1117fsX,
1137 12
1116 13 A1116V,
1138 13
1115 13 M1115T,
1139 13 P1139L,
1114 14
1140 14
1113 14
1141 14
1112 15
1142 15