KCNH2 Variant G594S Detail

We estimate the penetrance of LQTS for KCNH2 G594S is 59%. We are unaware of any observations of this variant in individuals. G594S is not present in gnomAD. G594S 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 G594S around 59% (5/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-4.718 0.943 0 0.79 66
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 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.

G594S has 32 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
594 0
595 3 K595N, K595N, K595E,
593 4 I593K, I593X, I593V, I593T, I593R,
590 6 G590D, G590V,
596 6 P596R, P596T, P596S, P596L,
591 7 D591N, D591H,
605 8 P605L,
604 8 G604S, G604C, G604D,
592 8 Q592X,
589 8 L589P,
583 8 I583V,
597 10 Y597C, Y597H,
606 10 S606P, S606Del, S606F,
603 11 G603D,
633 11 N633S, N633I, N633D,
634 11 T634A, T634S, T634S, T634P, T634I,
588 11 N588D, N588K, N588K,
609 12 D609G, D609N,
584 12 G584S, G584C, G584R,
587 12
635 12 N635I,
586 12 L586M,
577 12
610 13
587 14
613 14 T613M, T613K, T613A, T613L,
607 14
608 15
629 15 N629K, N629S, N629I, N629K, N629D, N629T,
638 15 K638E, K638R, K638Del, K638D,
588 15 N588D, N588K, N588K,
585 15 W585C, W585C,