KCNH2 Variant R1069T Detail

We estimate the penetrance of LQTS for KCNH2 R1069T is 8%. We are unaware of any observations of this variant in individuals. R1069T is not present in gnomAD. We have tested the trafficking efficiency of this variant, 99% 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. R1069T 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 R1069T around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-4.061 0.981 -2 0.765 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.

R1069T 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
1069 0 R1069S, R1069S,
1068 4 Q1068X, Q1068R,
1070 4 Q1070X, Q1070P,
1067 5
1071 5 M1071V,
1066 7
1072 7 T1072S, T1072M,
1065 8
1073 8 L1073P,
1064 8 L1064X,
1074 8
1063 9 V1063I, V1063L,
1075 9 P1075L,
1062 10 T1062I, T1062X, T1062P,
1076 10
1061 11 A1061P,
1077 11 A1077T, A1077D,
1060 11 M1060V, M1060I, M1060I, M1060I,
1078 11 Y1078C,
1059 12 D1059E, D1059E,
1079 12 S1079N,
1058 13 A1058T, A1058E,
1080 13
1057 13 S1057fsX, S1057N,
1081 13
1056 14 L1056fsX,
1082 14
1055 14 R1055W, R1055Q,
1083 14 T1083fsX, T1083A,
1054 15 T1054fsX,
1084 15 P1084L, P1084R, P1084X,