NM_000238.4:c.2467C>T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000238.4(KCNH2):c.2467C>T(p.Arg823Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,632 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5O:1

Conservation

PhyloP100: 0.246

Variant links:

Genes affected

KCNH2 (HGNC:6251): (potassium voltage-gated channel subfamily H member 2) This gene encodes a component of a voltage-activated potassium channel found in cardiac muscle, nerve cells, and microglia. Four copies of this protein interact with one copy of the KCNE2 protein to form a functional potassium channel. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, May 2022]

KCNH2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a binding_site (size 100) in uniprot entity KCNH2_HUMAN there are 17 pathogenic changes around while only 0 benign (100%) in NM_000238.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.984

PP5

Variant 7-150948981-G-A is Pathogenic according to our data. Variant chr7-150948981-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 67402.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-150948981-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.2467C>T	p.Arg823Trp	missense_variant	Exon 10 of 15	ENST00000262186.10	NP_000229.1	Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KCNH2	ENST00000262186.10 link	c.2467C>T	p.Arg823Trp	missense_variant	Exon 10 of 15	1	NM_000238.4	ENSP00000262186.5	Q12809-1
KCNH2	ENST00000330883.9 link	c.1447C>T	p.Arg483Trp	missense_variant	Exon 6 of 11	1		ENSP00000328531.4	Q12809-2
KCNH2	ENST00000684241.1 link	n.3300C>T		non_coding_transcript_exon_variant	Exon 8 of 13

Frequencies

GnomAD3 genomes

AF:

0.00000659

AC:

AN:

151804

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251454

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135900

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461828

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727212

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000659

AC:

AN:

151804

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74158

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Pathogenic:2

Dec 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 823 of the KCNH2 protein (p.Arg823Trp). This variant is present in population databases (rs199473538, gnomAD 0.0009%). This missense change has been observed in individuals with long QT syndrome (PMID: 10973849, 11854117, 16831322, 19695459, 19716085, 23158531, 23631430). ClinVar contains an entry for this variant (Variation ID: 67402). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects KCNH2 function (PMID: 11741928, 16432067, 23303164). For these reasons, this variant has been classified as Pathogenic. -

Nov 07, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: KCNH2 c.2467C>T (p.Arg823Trp) results in a non-conservative amino acid change located in the Cyclic nucleotide-binding domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251454 control chromosomes. c.2467C>T has been reported in the literature in multiple individuals and families affected with Long QT Syndrome (eg. Splawski_2000, Moss_2002, Lieve_2013). These data indicate that the variant is very likely to be associated with disease. In experimental studies, the variant was found to result in deficient trafficking, reduced repolarization, and inability to be rescued by channel blockers (Jou_2013, Anderson_2006, Ficker_2002). Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Congenital long QT syndrome

Pathogenic:1Other:1

Jun 12, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Arg823Trp variant in KCNH2 has been reported in >10 individuals with long QT syndrome (Splawski 2000, Moss 2002, Kapplinger 2009, Nishio 2009, Crotti 2012 , Lieve 2013, Itoh 2016, ClinVar Variation ID 67402) and has also been reported in ClinVar (Variation ID 67402). In vitro functional studies provide some eviden ce that the p.Arg823Trp variant may impact protein function (Ficker 2002, Roti 2 002, Anderson 2006). The p.Arg823Trp variant has also been identified in 1/11170 2 of European chromosomes by the Genome Aggregation Database (gnomAD, http://gno mad.broadinstitute.org/; dbSNP rs199473538). Computational prediction tools and conservation analysis suggest that the variant may impact the protein, though th is information is not predictive enough to determine pathogenicity. In summary, although additional studies are required to fully establish its clinical signifi cance, the p.Arg823Trp variant is likely pathogenic. -

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:10973849;PMID:11854117;PMID:16432067;PMID:16831322;PMID:19716085;PMID:11741928). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

not provided

Pathogenic:1

Feb 17, 2016

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: provider interpretation

- -

Cardiovascular phenotype

Pathogenic:1

Feb 20, 2019

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R823W variant (also known as c.2467C>T), located in coding exon 10 of the KCNH2 gene, results from a C to T substitution at nucleotide position 2467. The arginine at codon 823 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration has been reported in a number of patients with long QT syndrome (Splawski I et al, Circulation 2000 Sep; 102(10):1178-85; Moss AJ et al, Circulation 2002 Feb; 105(7):794-9; Kapplinger JD et al, Heart Rhythm 2009 Sep; 6(9):1297-303; Nishio Y et al, J. Am. Coll. Cardiol. 2009 Aug; 54(9):812-9; Crotti L et al, J. Am. Coll. Cardiol. 2012 Dec; 60(24):2515-24; Itoh H et al, Eur. J. Hum. Genet. 2015 Dec; Izumi G et al, Pediatr Cardiol 2016 Apr). Studies in cultured cell lines and zebrafish embryos suggested this alteration causes protein traffic deficiency that would compromise channel functions (Ficker E et al, J. Biol. Chem. 2002 Feb; 277(7):4989-98; Anderson CL et al, Circulation 2006 Jan; 113(3):365-73; Jou CJ et al, Circ. Res. 2013 Mar; 112(5):826-30). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.98

.;D

Eigen

Uncertain

0.30

Eigen_PC

Benign

0.12

FATHMM_MKL

Benign

0.76

LIST_S2

Pathogenic

0.99

D;D

M_CAP

Pathogenic

0.78

MetaRNN

Pathogenic

0.98

D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.1

.;H

PrimateAI

Pathogenic

0.89

PROVEAN

Pathogenic

-7.1

D;D

REVEL

Pathogenic

0.93

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

0.97

MutPred

0.86

.;Loss of disorder (P = 0.0227);

MVP

1.0

MPC

2.2

ClinPred

1.0

GERP RS

0.88

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.93

gMVP

0.97

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over