KCNH2 Variant Y1009H Detail

We estimate the penetrance of LQTS for KCNH2 Y1009H is 9%. We are unaware of any observations of this variant in individuals. Y1009H is not present in gnomAD. We have tested the trafficking efficiency of this variant, 93% 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. Y1009H 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 Y1009H around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.872 0.998 2 0.754 4
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.

Y1009H 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
1009 0 Y1009X,
1008 4
1010 4
1007 5 R1007C, R1007H,
1011 5 E1011K,
1006 7 G1006fsX, G1006V,
1012 7 L1012fsX,
1005 8 R1005fsX, R1005Q,
1013 8
1004 8 S1004I, S1004T,
1014 8 R1014fsX, R1014X,
1003 9 D1003H, D1003Y,
1015 9 C1015Y,
1002 10 G1002E,
1016 10
1001 11 W1001X, W1001C, W1001C,
1017 11 A1017V, A1017T, A1017S, A1017fsX,
1000 11
1018 11 P1018L, P1018A,
999 12 S999X,
1019 12
998 13
1020 13
997 13 I997X,
1021 13 S1021N, S1021fsX,
996 14 N996X, N996I,
1022 14
995 14
1023 14 L1023P, L1023Del,
994 15
1024 15