KCNH2 Variant D803Y Detail

We estimate the penetrance of LQTS for KCNH2 D803Y is 55%. This variant was found in a total of 2 carriers in 1 papers or gnomAD, 1 had LQTS. D803Y is not present in gnomAD. D803Y 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 5 individuals with LQT2 and 5 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 D803Y around 55% (6/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-8.285 1.0 -3 0.976 56
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
30244407 2018 2 1 1
LITERATURE, COHORT, AND GNOMAD: - 2 1 1 -
VARIANT FEATURES ALONE: - 10 5 5 -
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.

D803Y has 69 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
803 0 D803X, D803Y,
800 5
782 5 I782N, I782fsX,
802 5
804 5
799 5 L799sp,
859 6 T859R, T859M,
56 7 R56Q,
801 7 K801T,
781 7
805 7 F805C, F805S,
783 8 S783P,
787 8
858 9 I858T, I858V,
785 9 G785fsX, G785S, G785D,
798 9 I798fsX,
44 10 C44X, C44F, C44W,
860 10
786 10
740 10 C740W, C740G,
857 10 E857X,
830 10
780 10
43 10 Y43D, Y43C,
736 10
57 11 A57P,
46 11 D46Y, D46E, D46E,
797 11 A797T,
831 11
60 11 M60T,
741 11 K741R,
806 11 G806R, G806R,
55 11 S55L,
856 11
779 11
828 11
784 12 R784W, R784G, R784Q,
735 12 S735L,
829 12 D829E, D829E, D829A,
789 12
45 12 N45K, N45D, N45K,
739 12 H739fsX,
788 12 E788D, E788K, E788D,
49 13 C49G, C49R,
42 13 I42N,
742 13
822 13 V822L, V822L, V822M,
59 13
861 13 N861H, N861I,
824 14
743 14
862 14 L862P,
826 14 T826I, T826A,
19 14 I19F,
825 14
796 14 V796L, V796Del, V796L,
832 14
58 14 E58D, E58K, E58D,
855 14 S855R, S855R, S855R,
761 14
61 14 Q61R,
778 14 A778T,
769 14
763 14
737 15 L737P,
833 15
41 15 V41A,
16 15 D16A,
47 15 G47C, G47V,