KCNH2 Variant D837Y Detail

We estimate the penetrance of LQTS for KCNH2 D837Y is 42%. This variant was found in a total of 2 carriers in 1 papers or gnomAD (version 4), 2 had LQTS. D837Y is not present in gnomAD. We have tested the trafficking efficiency of this variant, 0% of WT with a standard error of 2%; 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. D837Y has not been functionally characterized. This residue is located in a Hotspot region for LQT2. In silico predictions, functional data (if available), and location in structure are equivalent to observing 3 individuals with LQT2 and 7 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 D837Y around 42% (5/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-8.115 1.0 -3 0.944 70
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
26496715 2015 2 0 2
LITERATURE, COHORT, AND GNOMAD: - 2 0 2 -
VARIANT FEATURES ALONE: - 10 7 3 -
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.

D837Y has 37 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
837 0 D837N, D837G, D837Y,
757 5
836 5
834 5 H834R,
838 6 L838R,
840 6 E840Q,
833 6
839 7
835 8 R835W, R835Q, R835fsX,
841 8 V841L, V841L,
758 9
754 9
759 9 K759N, K759N,
777 9
832 10
778 10 A778T,
753 10 A753S,
756 10 M756V,
842 10
779 10
755 10
843 11
809 12
844 12 M844V,
780 13
845 14
776 14 L776P, L776I,
750 14 C750X,
781 14
831 14
729 14
852 14
760 14
815 14
853 14 W853X,
733 15
751 15 L751V,