KCNH2 Variant N629I Detail

We estimate the penetrance of LQTS for KCNH2 N629I is 90%. This variant was found in a total of 1 carriers in 1 papers or gnomAD, 1 had LQTS. N629I is not present in gnomAD. N629I 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 N629I around 90% (9/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-8.701 1.0 -4 0.893 96
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
19038855 2009 1 0 1 Seizure
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.

N629I has 77 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
629 0 N629T, N629I, N629K, N629D, N629K, N629S,
628 4 G628Del, G628R, G628D, G628V, G628S, G628A,
630 5 V630T, V630I, V630A,
631 5 S631F,
632 6 P632A, P632S,
633 6 N633D, N633S, N633I,
627 6 F627L, F627L, F627fsX, F627X, F627L,
592 7 Q592X,
616 7 Y616S,
631 7 S631F,
628 8 G628Del, G628R, G628D, G628V, G628S, G628A,
638 8 K638D, K638R, K638E, K638Del,
626 9 G626A, G626S, G626V,
613 9 T613M, T613K, T613A, T613L,
630 9 V630T, V630I, V630A,
588 9 N588K, N588K, N588D,
589 9 L589P,
617 9 F617V, F617L, F617L, F617L,
628 10 G628Del, G628R, G628D, G628V, G628S, G628A,
627 10 F627L, F627L, F627fsX, F627X, F627L,
634 10 T634P, T634I, T634S, T634S, T634A,
637 10 E637K, E637G, E637X,
620 10 S620G, S620I,
626 10 G626A, G626S, G626V,
629 10 N629T, N629I, N629K, N629D, N629K, N629S,
629 10 N629T, N629I, N629K, N629D, N629K, N629S,
593 11 I593R, I593X, I593T, I593V, I593K,
588 11 N588K, N588K, N588D,
585 11 W585C, W585C,
641 11 S641F, S641P,
584 11 G584S, G584R, G584C,
632 11 P632A, P632S,
625 11 V625E,
614 11 A614V, A614T,
591 12 D591H, D591N,
617 12 F617V, F617L, F617L, F617L,
628 12 G628Del, G628R, G628D, G628V, G628S, G628A,
626 12 G626A, G626S, G626V,
590 12 G590V, G590D,
612 12 V612L, V612L, V612A,
635 12 N635I,
627 12 F627L, F627L, F627fsX, F627X, F627L,
585 12 W585C, W585C,
633 13 N633D, N633S, N633I,
621 13 S621R, S621N, S621R, S621R,
583 13 I583V,
609 13 D609N, D609G,
586 13 L586M,
621 13 S621R, S621N, S621R, S621R,
568 13 W568C, W568C,
584 13 G584S, G584R, G584C,
642 13 I642V, I642Del,
626 13 G626A, G626S, G626V,
615 13 L615V, L615F,
618 13 T618S, T618S,
645 13 M645I, M645V, M645I, M645L, M645I, M645L, M645R,
636 13
620 13 S620G, S620I,
625 13 V625E,
568 13 W568C, W568C,
639 14 I639F, I639N,
625 14 V625E,
592 14 Q592X,
640 14 F640L, F640L, F640Del, F640L, F640V,
619 14
637 14 E637K, E637G, E637X,
630 14 V630T, V630I, V630A,
610 14
631 14 S631F,
594 15
627 15 F627L, F627L, F627fsX, F627X, F627L,
616 15 Y616S,
589 15 L589P,
592 15 Q592X,
587 15
629 15 N629T, N629I, N629K, N629D, N629K, N629S,
624 15 S624R, S624R, S624R, S624N,