KCNH2 Variant R1035Q Detail

We estimate the penetrance of LQTS for KCNH2 R1035Q is 3%. This variant was found in a total of 29 carriers in 0 papers or gnomAD (version 4), 0 had LQTS. R1035Q is present in 29 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 59% of WT with a standard error of 17%; 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. R1035Q 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 1 individuals with LQT2 and 9 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 R1035Q around 3% (1/39).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.75 0.921 -1 0.573 10
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: - 29 10 0 -
VARIANT FEATURES ALONE: - 10 9 1 -
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.

R1035Q 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
1035 0 R1035X, R1035fsX, R1035W, R1035Q,
1034 4 P1034fsX, P1034X,
1036 4 G1036fsX, G1036Del, G1036D, G1036X,
1033 5 R1033X, R1033fsX, R1033Q, R1033W,
1037 5 D1037E, D1037fsX, D1037E, D1037X, D1037N,
1032 7 R1032Q, R1032W, R1032P, R1032fsX, R1032X,
1038 7 V1038M, V1038L, V1038X, V1038L, V1038fsX,
1031 8 G1031X, G1031C, G1031fsX,
1039 8 E1039X,
1030 8 P1030L, P1030X,
1040 8
1029 9 S1029fsX,
1041 9
1028 10 S1028Del,
1042 10
1027 11 L1027I,
1043 11 D1043G,
1026 11 P1026R,
1044 11
1025 12
1045 12 L1045F,
1024 13
1046 13 Q1046X,
1023 13 L1023P, L1023Del,
1047 13 R1047C, R1047L, R1047H,
1022 14
1048 14
1021 14 S1021fsX, S1021N,
1049 14
1020 15
1050 15