rs199473670

Positions:

chr7-150947812-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_000238.4(KCNH2):c.2759G>A(p.Arg920Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000177 in 1,529,310 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R920G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1O:1

Conservation

PhyloP100: -0.0940

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 Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAdExome4 at 23 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4 linkuse as main transcript	c.2759G>A	p.Arg920Gln	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.2759G>A	p.Arg920Gln	missense_variant	12/15	1	NM_000238.4	P1	Q12809-1
KCNH2	ENST00000330883.9 linkuse as main transcript	c.1739G>A	p.Arg580Gln	missense_variant	8/11	1			Q12809-2
KCNH2	ENST00000684241.1 linkuse as main transcript	n.3592G>A		non_coding_transcript_exon_variant	10/13

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152120

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

125596

Hom.:

AF XY:

0.0000292

AC XY:

AN XY:

68594

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000125

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000472

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000216

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000167

AC:

AN:

1377190

Hom.:

Cov.:

AF XY:

0.0000177

AC XY:

AN XY:

678816

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000170

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000385

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000112

Gnomad4 OTH exome

AF:

0.0000174

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152120

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ExAC

AF:

0.0000475

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 22, 2024	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 920 of the KCNH2 protein (p.Arg920Gln). 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 missense change has been observed in individual(s) with long QT syndrome (PMID: 19716085, 23631430). ClinVar contains an entry for this variant (Variation ID: 67434). 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 glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Dec 01, 2023	This missense variant replaces arginine with glutamine 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 individuals affected with or suspected of having long QT syndrome (PMID: 19716085, 23631430, 33029862, ClinVar SCV001813917.1). This variant has been identified in 7/156894 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

GeneDx

Mar 27, 2023

Observed in association with LQTS in the published literature and in individuals referred for genetic testing at GeneDx; however, clinical details are lacking and segregation data are currently uninformative (Kapplinger et al., 2009; Lieve et al., 2013; internal data); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 23631430, 22581653, 19716085) -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 21, 2022

This missense variant replaces arginine with glutamine 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 individuals affected with or suspected of having long QT syndrome (PMID: 19716085, 23631430, 33029862, ClinVar SCV001813917.1). This variant has been identified in 7/156894 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. -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 08, 2023

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

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

0.077

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Uncertain

0.10

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.34

.;T

Eigen

Benign

-0.56

Eigen_PC

Benign

-0.48

FATHMM_MKL

Benign

0.093

LIST_S2

Benign

0.77

T;T

M_CAP

Uncertain

0.29

MetaRNN

Uncertain

0.66

D;D

MetaSVM

Uncertain

0.41

MutationAssessor

Benign

0.90

.;L

MutationTaster

Benign

0.79

N;N;N

PrimateAI

Uncertain

0.49

PROVEAN

Benign

-0.84

N;N

REVEL

Uncertain

0.54

Sift

Benign

0.27

T;T

Sift4G

Benign

0.14

T;T

Polyphen

0.0060

B;B

Vest4

0.27

MutPred

0.81

.;Loss of methylation at R920 (P = 0.0083);

MVP

0.99

MPC

0.26

ClinPred

0.050

GERP RS

2.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.096

gMVP

0.54

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