KCNH2 Variant A1044D Detail

We estimate the penetrance of LQTS for KCNH2 A1044D is 8%. We are unaware of any observations of this variant in individuals. A1044D is not present in gnomAD. We have tested the trafficking efficiency of this variant, 114% of WT with a standard error of 16%; 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. A1044D 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 A1044D around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.915 0.937 -5 0.527 3
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.

A1044D 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
1044 0
1043 4 D1043G,
1045 4 L1045F,
1042 5
1046 5 Q1046X,
1041 7
1047 7 R1047H, R1047C, R1047L,
1040 8
1048 8
1039 8 E1039X,
1049 8
1038 9 V1038L, V1038X, V1038L, V1038M, V1038fsX,
1050 9
1037 10 D1037fsX, D1037E, D1037N, D1037E, D1037X,
1051 10
1036 11 G1036D, G1036fsX, G1036X, G1036Del,
1052 11
1035 11 R1035fsX, R1035Q, R1035W, R1035X,
1053 11 E1053fsX, E1053X,
1034 12 P1034fsX, P1034X,
1054 12 T1054fsX,
1033 13 R1033fsX, R1033X, R1033Q, R1033W,
1055 13 R1055W, R1055Q,
1032 13 R1032Q, R1032W, R1032fsX, R1032P, R1032X,
1056 13 L1056fsX,
1031 14 G1031C, G1031fsX, G1031X,
1057 14 S1057N, S1057fsX,
1030 14 P1030X, P1030L,
1058 14 A1058T, A1058E,
1029 15 S1029fsX,
1059 15 D1059E, D1059E,