rs199473438

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3

The NM_000238.4(KCNH2):c.2758C>T(p.Arg920Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000144 in 1,529,092 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R920Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5O:1

Conservation

PhyloP100: 1.20

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 Uncertain_significance. Variant got 1 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.753

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4 linkuse as main transcript	c.2758C>T	p.Arg920Trp	missense_variant	12/15	ENST00000262186.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH2	ENST00000262186.10 linkuse as main transcript	c.2758C>T	p.Arg920Trp	missense_variant	12/15	1	NM_000238.4	P1	Q12809-1
KCNH2	ENST00000330883.9 linkuse as main transcript	c.1738C>T	p.Arg580Trp	missense_variant	8/11	1			Q12809-2
KCNH2	ENST00000684241.1 linkuse as main transcript	n.3591C>T		non_coding_transcript_exon_variant	10/13

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152062

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

125518

Hom.:

AF XY:

0.00

AC XY:

AN XY:

68518

show subpopulations

Gnomad AFR exome

AF:

0.000160

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000138

AC:

AN:

1377030

Hom.:

Cov.:

AF XY:

0.0000147

AC XY:

AN XY:

678700

show subpopulations

Gnomad4 AFR exome

AF:

0.0000319

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000281

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000282

Gnomad4 NFE exome

AF:

0.0000140

Gnomad4 OTH exome

AF:

0.0000174

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152062

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74288

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:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Apr 04, 2023	In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The tryptophan amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 67433). This missense change has been observed in individual(s) with clinical features of KCNH2-related conditions (PMID: 19716085). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 920 of the KCNH2 protein (p.Arg920Trp). -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Feb 05, 2024	This missense variant replaces arginine with tryptophan at codon 920 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic test (PMID: 19716085). This variant has been identified in 1/125518 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Mar 01, 2023

KCNH2: PM5, PM2:Supporting, PP2 -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 02, 2019

The c.2758C>T (p.R920W) alteration is located in exon 12 (coding exon 12) of the KCNH2 gene. This alteration results from a C to T substitution at nucleotide position 2758, causing the arginine (R) at amino acid position 920 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Mar 20, 2023

This missense variant replaces arginine with tryptophan at codon 920 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic test (PMID: 19716085). This variant has been identified in 1/125518 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Congenital long QT syndrome

Other:1

not provided, no classification provided

literature only

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

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

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

CardioboostArm

Benign

0.0021

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.20

Cadd

Benign

Dann

Uncertain

1.0

Eigen

Benign

-0.17

Eigen_PC

Benign

-0.16

FATHMM_MKL

Benign

0.40

LIST_S2

Benign

0.82

T;T

M_CAP

Pathogenic

0.50

MetaRNN

Pathogenic

0.75

D;D

MetaSVM

Uncertain

0.57

MutationTaster

Benign

0.87

D;D;D

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-2.5

N;N

REVEL

Pathogenic

0.69

Sift

Benign

0.17

T;T

Sift4G

Uncertain

0.052

T;D

Polyphen

1.0

D;B

Vest4

0.33

MutPred

0.77

.;Loss of solvent accessibility (P = 6e-04);

MVP

0.97

MPC

0.17

ClinPred

0.42

GERP RS

2.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.087

gMVP

0.62

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