rs775317201

Positions:

chr7-150977888-G-A

Variant summary

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

The NM_000238.4(KCNH2):c.26C>T(p.Ala9Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000125 in 1,605,404 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 28)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 5.29

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 18 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
KCNH2	NM_000238.4 linkuse as main transcript	c.26C>T	p.Ala9Val	missense_variant	1/15	ENST00000262186.10	NP_000229.1
KCNH2	NM_172056.3 linkuse as main transcript	c.26C>T	p.Ala9Val	missense_variant	1/9		NP_742053.1
KCNH2	NR_176254.1 linkuse as main transcript	n.434C>T		non_coding_transcript_exon_variant	1/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10 linkuse as main transcript	c.26C>T	p.Ala9Val	missense_variant	1/15	1	NM_000238.4	ENSP00000262186	P1	Q12809-1
KCNH2	ENST00000532957.5 linkuse as main transcript	n.249C>T		non_coding_transcript_exon_variant	1/9	2

Frequencies

GnomAD3 genomes

AF:

0.0000134

AC:

AN:

149548

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000246

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:

0.0000149

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000168

AC:

AN:

238628

Hom.:

AF XY:

0.0000229

AC XY:

AN XY:

131278

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:

0.0000377

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000124

AC:

AN:

1455856

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

724150

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.0000499

GnomAD4 genome

AF:

0.0000134

AC:

AN:

149548

Hom.:

Cov.:

AF XY:

0.0000137

AC XY:

AN XY:

72948

show subpopulations

Gnomad4 AFR

AF:

0.0000246

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:

0.0000149

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.00000836

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jan 07, 2019	The Ala9Val variant in the KCNH2 gene has not been reported as a disease-causing mutation or as a benign polymorphism to our knowledge. Ala9Val results in a conservative amino acid substitution of one non-polar amino acid with another at a position that is conserved across species. In silico analysis predicts Ala9Val is probably damaging to the protein structure/function. Mutations in nearby codons (Met1Leu, Asp16Ala) have been reported in association with LQTS, supporting the functional importance of this region of the protein. The NHLBI ESP Exome Variant Server reports Ala9Val was not observed in approximately 6,000 samples from individuals of European and African American backgrounds, indicating it is not a common benign variant in these populations.With the clinical and molecular information available at this time, we cannot definitively determine if Ala9Val is a disease-causing mutation or a rare benign variant. -
Uncertain significance, no assertion criteria provided	provider interpretation	Stanford Center for Inherited Cardiovascular Disease, Stanford University	Sep 12, 2016	- -

Long QT syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 30, 2023	This missense variant replaces alanine with valine at codon 9 of the KCNH2 protein. Computational prediction tool suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >=0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/268000 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 14, 2023	This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 9 of the KCNH2 protein (p.Ala9Val). 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 variant has not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 200592). 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 tolerated. 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. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 02, 2022

The p.A9V variant (also known as c.26C>T), located in coding exon 1 of the KCNH2 gene, results from a C to T substitution at nucleotide position 26. The alanine at codon 9 is replaced by valine, an amino acid with similar properties. This alteration was reported in a group of subjects who had medical record review based on prescribed medications with relevant pharmacogenomic interactions (Van Driest SL et al. JAMA, 2016 Jan;315:47-57). This alteration has also been reported in a long QT syndrome (LQTS) cohort (Walsh R et al. Genet Med, 2021 01;23:47-58). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Short QT syndrome type 1;C3150943:Long QT syndrome 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Sep 13, 2021

- -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 19, 2022

This missense variant replaces alanine with valine at codon 9 of the KCNH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with long QT syndrome (PMID: 32893267). This variant has been identified in 5/268000 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Uncertain

0.010

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.59

Eigen

Uncertain

0.44

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Uncertain

0.87

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

1.0

MetaRNN

Uncertain

0.60

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.4

MutationTaster

Benign

0.70

D;D

PrimateAI

Pathogenic

0.91

PROVEAN

Benign

-2.2

REVEL

Pathogenic

0.72

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0030

Polyphen

0.94

Vest4

0.34

MutPred

0.45

Loss of methylation at R5 (P = 0.1107);

MVP

0.78

MPC

1.3

ClinPred

0.69

GERP RS

2.5

Varity_R

0.22

gMVP

0.88

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