KCNH2 Variant S1079C Detail

We estimate the penetrance of LQTS for KCNH2 S1079C is 8%. We are unaware of any observations of this variant in individuals. S1079C is not present in gnomAD. We have tested the trafficking efficiency of this variant, 127% of WT with a standard error of 5%; 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. S1079C 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 S1079C around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-3.436 0.999 -3 0.8 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.

S1079C 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
1079 0 S1079N,
1078 4 Y1078C,
1080 4
1077 5 A1077T, A1077D,
1081 5
1076 7
1082 7
1075 8 P1075L,
1083 8 T1083A, T1083fsX,
1074 8
1084 8 P1084L, P1084X, P1084R,
1073 9 L1073P,
1085 9 G1085X,
1072 10 T1072M, T1072S,
1086 10 P1086fsX, P1086X,
1071 11 M1071V,
1087 11 G1087X,
1070 11 Q1070P, Q1070X,
1088 11
1069 12 R1069S, R1069S,
1089 12 T1089A, T1089I,
1068 13 Q1068R, Q1068X,
1090 13 S1090F,
1067 13
1091 13
1066 14
1092 14 S1092F,
1065 14
1093 14 P1093R, P1093L,
1064 15 L1064X,
1094 15 L1094M,