KCNH2 Variant H562Q

Summary of observed carriers, functional annotations, and structural context for KCNH2 H562Q. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT2 penetrance

31%

3/12 effective observations

Total carriers

2

0 LQT2 · 2 unaffected

Functional studies

1

Publications with functional data

H562Q has not been reported in gnomAD. This residue resides in a Hotspot region for LQT2.

We have tested the trafficking efficiency of this variant: 0% of WT with a standard error of 5%. 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.

Variant features alone are equivalent to phenotyping 3 individuals with LQT2 and 7 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT2 (%)
-7.668 0.989 0 0.92 60

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. BLAST-PSSM reflects evolutionary conservation; more negative values indicate rarer substitutions. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT2 Other Disease
Japan Cohort 2020 2 2 0
Literature, cohort, and gnomAD 2 2 0
Variant features alone 10 7 3

Totals may differ from individual publications due to duplicate patients removed during curation.

Functional data

Functional assay results from published electrophysiology studies. Steady state (S.S.) and peak tail current are relative % to wildtype (100% being no different from wildtype). V1/2 activation and inactivation are the voltages at which half of the maximal current is reached, in mV. Recovery from inactivation and deactivation time are ratios of characteristic time constants with wildtype. HM indicates homomeric channels, HT indicates heteromeric channels.

Homomeric channel data

Published electrophysiology measurements (homomeric).
PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Recov. Inact. Deactivation (%WT)
22517356 Xeno 8 -11.2 None None None

Heteromeric channel data

Published electrophysiology measurements (heteromeric).
PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Deactivation (%WT)
22517356 Xeno None None None

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD. Note that 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 15Å window.

Previously observed variants near H562Q.
Neighbour residue Distance (Å) Observed variants
562 0 H562P, H562Q, H562R, H562Q,
561 5 A561T, A561P, A561V,
563 5 W563X, W563G, W563C, W563C,
559 5 L559H, L559F,
566 6 C566S, C566S, C566R, C566G, C566F,
423 6
565 6
558 6 A558V, A558E, A558P,
611 7 Y611D,
615 7 L615F, L615V,
426 7 P426H,
564 7 L564L,
422 7 A422T,
560 7 I560fsX, I560M,
427 8 Y427C, Y427S, Y427H,
614 9 A614V, A614T,
618 9 T618S, T618S,
424 9
567 9 I567T, I567M,
619 10
425 10
431 10 F431L, F431L, F431L,
612 10 V612L, V612A, V612L,
557 10
556 10
419 11
430 11
555 11
428 11 S428X, S428fsX, S428L,
421 11 T421M, T421fsX,
569 11 Y569X, Y569C, Y569H,
429 12 A429V, A429P,
529 12
642 12 I642Del, I642V,
568 12 W568C, W568C,
420 12 Y420C,
613 12 T613K, T613M, T613A, T613L,
617 12 F617L, F617V, F617L, F617L
622 12 L622F,
570 13
616 13 Y616S,
610 13
608 13
418 13
646 14
640 14 F640L, F640L, F640V, F640Del, F640L,
644 14 V644F, V644I,
639 14 I639N, I639F,
609 14 D609N, D609G,
607 14
554 14
532 14
526 14
620 14 S620G, S620I,
621 14 S621R, S621N, S621R, S621R,
432 15
645 15 M645I, M645V, M645I, M645I, M645L, M645L, M645R,
647 15
571 15 I571V, I571L,
651 15 M651K,
638 15 K638E, K638Del, K638R, K638D,
528 15 R528X, R528P, R528W,