KCNH2 Variant D1003N Detail

We estimate the penetrance of LQTS for KCNH2 D1003N is 6%. This variant was found in a total of 6 carriers in 0 papers or gnomAD (version 4), 0 had LQTS. D1003N is present in 6 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 69% of WT with a standard error of 13%; 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. D1003N 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 D1003N around 6% (0/16).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.574 0.9 -1 0.567 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: - 6 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.

D1003N 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
1003 0 D1003H, D1003Y,
1002 4 G1002E,
1004 4 S1004T, S1004I,
1001 5 W1001X, W1001C, W1001C,
1005 5 R1005fsX, R1005Q,
1000 7
1006 7 G1006V, G1006fsX,
999 8 S999X,
1007 8 R1007H, R1007C,
998 8
1008 8
997 9 I997X,
1009 9 Y1009X,
996 10 N996I, N996X,
1010 10
995 11
1011 11 E1011K,
994 11
1012 11 L1012fsX,
993 12
1013 12
992 13
1014 13 R1014fsX, R1014X,
991 13 F991fsX,
1015 13 C1015Y,
990 14 A990T,
1016 14
989 14 G989D, G989S,
1017 14 A1017S, A1017V, A1017T, A1017fsX,
988 15 S988L, S988P, S988A,
1018 15 P1018L, P1018A,