KCNH2 Variant G628Del Detail

We estimate the penetrance of LQTS for KCNH2 G628Del is 86%. This variant was found in a total of 1 carriers in 1 papers or gnomAD, 1 had LQTS. G628Del is not present in gnomAD. G628Del 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 8 individuals with LQT2 and 2 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 G628Del around 86% (9/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
None None None None 97
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
30036649 2018 1 0 1
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 -
VARIANT FEATURES ALONE: - 10 2 8 -
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.

G628Del has 82 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
628 0 G628A, G628D, G628S, G628Del, G628V, G628R,
629 4 N629S, N629I, N629T, N629D, N629K, N629K,
630 5 V630T, V630I, V630A,
627 6 F627L, F627L, F627X, F627L, F627fsX,
631 6 S631F,
626 6 G626V, G626S, G626A,
628 6 G628A, G628D, G628S, G628Del, G628V, G628R,
628 6 G628A, G628D, G628S, G628Del, G628V, G628R,
627 7 F627L, F627L, F627X, F627L, F627fsX,
631 7 S631F,
629 8 N629S, N629I, N629T, N629D, N629K, N629K,
632 8 P632A, P632S,
626 8 G626V, G626S, G626A,
626 8 G626V, G626S, G626A,
616 9 Y616S,
628 9 G628A, G628D, G628S, G628Del, G628V, G628R,
617 9 F617L, F617L, F617V, F617L,
632 9 P632A, P632S,
620 9 S620I, S620G,
630 9 V630T, V630I, V630A,
625 10 V625E,
633 10 N633D, N633S, N633I,
592 10 Q592X,
629 10 N629S, N629I, N629T, N629D, N629K, N629K,
588 10 N588K, N588K, N588D,
626 10 G626V, G626S, G626A,
627 10 F627L, F627L, F627X, F627L, F627fsX,
625 10 V625E,
613 11 T613K, T613L, T613M, T613A,
630 11 V630T, V630I, V630A,
627 11 F627L, F627L, F627X, F627L, F627fsX,
638 11 K638R, K638D, K638E, K638Del,
621 11 S621R, S621R, S621N, S621R,
633 11 N633D, N633S, N633I,
589 12 L589P,
585 12 W585C, W585C,
625 12 V625E,
629 12 N629S, N629I, N629T, N629D, N629K, N629K,
631 12 S631F,
641 12 S641P, S641F,
616 12 Y616S,
617 12 F617L, F617L, F617V, F617L,
625 13 V625E,
620 13 S620I, S620G,
621 13 S621R, S621R, S621N, S621R,
614 13 A614V, A614T,
631 13 S631F,
588 13 N588K, N588K, N588D,
620 13 S620I, S620G,
624 13 S624R, S624R, S624N, S624R,
592 13 Q592X,
641 13 S641P, S641F,
618 13 T618S, T618S,
568 13 W568C, W568C,
584 13 G584R, G584S, G584C,
637 13 E637K, E637G, E637X,
637 13 E637K, E637G, E637X,
645 13 M645L, M645I, M645R, M645L, M645I, M645V, M645I,
638 14 K638R, K638D, K638E, K638Del,
624 14 S624R, S624R, S624N, S624R,
630 14 V630T, V630I, V630A,
634 14 T634P, T634S, T634S, T634A, T634I,
591 14 D591H, D591N,
593 14 I593T, I593X, I593K, I593V, I593R,
623 14 T623I,
584 14 G584R, G584S, G584C,
616 14 Y616S,
624 14 S624R, S624R, S624N, S624R,
619 14
586 14 L586M,
615 14 L615V, L615F,
642 14 I642Del, I642V,
592 14 Q592X,
612 14 V612L, V612L, V612A,
590 14 G590V, G590D,
617 15 F617L, F617L, F617V, F617L,
585 15 W585C, W585C,
632 15 P632A, P632S,
645 15 M645L, M645I, M645R, M645L, M645I, M645V, M645I,
634 15 T634P, T634S, T634S, T634A, T634I,
588 15 N588K, N588K, N588D,
624 15 S624R, S624R, S624N, S624R,