A614V Summary

KCNH2 A614V was found in 17 papers (see below) with a total of 49 carriers: 48 had LQT2. A614V is not present in gnomAD. A614V has been functionally characterized in 5 papers. Given the functional data available, we estimate this variant has "Dominant LOF" in vitro character. (LOF and GOF denote loss-of-function and gain-of-function, respectively). 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 2 individuals unaffected with LQT2 and 8 individuals affected with LQT2.


A614V Reported Clinical Data

PMID Year Carriers Unaffected LQT2 Other disease
0 1
11854117 2002 3 0 3
14642690 1 0 1
15090700 2004 2 0 2
15840476 2005 2 0 2
18808722 2008 1 0 1
19070294 2008 9 0 9
19843919 2009 1 1
19996378 2009 1 0 1
23864605 2013 25 0
24218437 2013 1 0 congenital LQT
26496715 2015 9 0 9
27555138 2016 1 0 1
9544837 1998 4 0 4
9693036 1998 10 0 10
Italy Cohort 2020 2 0 2
Japan Cohort 2020 11 1 10
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts.

A614V Reported Functional Data: heterozygously collected

Steady state (S.S.) and peak tail current are relative % to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype. Recovery from inactivation (Rec. inact.) and deactivation time (Deactivation) are the ratio of characteristic time constants with wildtype (unitless).

PMID Year Cell type S.S. peak current (%WT) Peak tail current (%WT) V0.5 act V0.5 inact Rec. inact. (%WT) Deactivation (%WT)
9721698 1998 Xeno 35.5 17.5 3.1 -9.3 100 100
16432067 2006 HEK293
21240260 2011 hiPSC-CM 33.3
23864605 2013 HEK293

A614V Reported Functional Data: homozygously collected

PMID Year Cell type S.S. peak current (%WT) Peak tail current (%WT) V0.5 act V0.5 inact Rec. inact. (%WT) Deactivation (%WT)
9721698 1998 Xeno 0 0
16432067 2006 HEK293 10
21240260 2011 hiPSC-CM
23864605 2013 HEK293

A614V Predictions

PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 is 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. PAM scores reflect the chemistry difference between WT and variant amino acid (more negative being greater difference between the two). BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected.

PAM Score REVEL Score PROVEAN Score Polyphen2 Score BLAST-PSSM
-2 0.961 -3.792 1 0

A614V has 79 neighbors (found in individuals) within 15 ångströms

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. This results from the fact that the functional Kv11.1 channel 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.

ResidueNumber Distance(Å) Variants
423 14.1
426 13.1 P426H
427 11.6 Y427C Y427H Y427S
429 15 A429P A429V
430 12
431 10.1 F431L
557 14.2
558 12.3 A558E A558P A558V
559 13.5 L559F L559H
560 12.7 I560fsX I560M
561 8.5 A561P A561T A561V
562 9 H562P H562Q H562R
563 12.3 W563C W563G W563X
564 8.4 L564L
565 4.7
566 7.6 C566F C566G C566R C566S
567 9.4 I567M I567T
568 5.9 W568C
569 7.8 Y569C Y569H Y569X
570 10.5
571 10.8 I571L I571V
572 11.2 G572C G572D G572R G572S
573 12.4
584 13.5 G584C G584R G584S
585 7.6 W585C
586 10 L586M
587 14.9
588 12.9 N588D N588K
589 10.3 L589P
590 14.5 G590D G590V
592 13.5 Q592X
593 13.7 I593K I593R I593T I593V I593X
605 12.8 P605L
606 12.1 S606Del S606F S606P
607 11
608 11
609 8.1 D609G D609N
610 7.8
611 5.8 Y611D
612 5.6 V612A V612L
613 3.9 T613A T613K T613L T613M
615 4.4 L615F L615V
616 6.6 Y616S
617 5.6 F617L F617V
618 6.2 T618S
619 8.9
620 9.5 S620G S620I
621 10.5 S621N S621R
622 11.9 L622F
623 13.6 T623I
625 14.1 V625E
626 13.2 G626A G626S G626V
627 12.2 F627fsX F627L F627X
627 13.6 F627fsX F627L F627X
628 12.6 G628A G628D G628Del G628R G628S G628V
629 11.4 N629D N629I N629K N629S N629T
630 8.2 V630A V630I V630T
631 14.8 S631F
631 11 S631F
632 12.1 P632A P632S
632 12 P632A P632S
633 14.9 N633D N633I N633S
633 12.9 N633D N633I N633S
634 13.3 T634A T634I T634P T634S
635 11 N635I
636 14.6
636 14.1
637 11.6 E637G E637K E637X
637 14.2 E637G E637K E637X
638 8.8 K638D K638Del K638E K638R
639 11.2 I639F I639N
640 10.6 F640Del F640L F640V
641 12.4 S641F S641P
641 11.9 S641F S641P
642 10 I642Del I642V
643 15
644 12.1 V644F V644I
645 12.4 M645I M645L M645R M645V
646 15