rs794728399

Positions:

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BS2_Supporting

The NM_000238.4(KCNH2):c.2780G>T(p.Trp927Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000365 in 1,534,306 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000035 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:1

Conservation

PhyloP100: 5.12

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 -1 ACMG points.

BS2

High AC in GnomAd4 at 8 AD,Digenic gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH2	NM_000238.4 linkuse as main transcript	c.2780G>T	p.Trp927Leu	missense_variant	12/15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10 linkuse as main transcript	c.2780G>T	p.Trp927Leu	missense_variant	12/15	1	NM_000238.4	ENSP00000262186	P1	Q12809-1
KCNH2	ENST00000330883.9 linkuse as main transcript	c.1760G>T	p.Trp587Leu	missense_variant	8/11	1		ENSP00000328531		Q12809-2
KCNH2	ENST00000684241.1 linkuse as main transcript	n.3613G>T		non_coding_transcript_exon_variant	10/13

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.0000588

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.0000685

AC:

AN:

131454

Hom.:

AF XY:

0.0000695

AC XY:

AN XY:

71944

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000206

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:

0.0000412

Gnomad OTH exome

AF:

0.000498

GnomAD4 exome

AF:

0.0000347

AC:

AN:

1382162

Hom.:

Cov.:

AF XY:

0.0000293

AC XY:

AN XY:

681522

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000141

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000380

Gnomad4 FIN exome

AF:

0.0000269

Gnomad4 NFE exome

AF:

0.0000288

Gnomad4 OTH exome

AF:

0.000122

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152144

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.000479

Alfa

AF:

0.0000384

Hom.:

Bravo

AF:

0.0000264

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, no assertion criteria provided	provider interpretation	Stanford Center for Inherited Cardiovascular Disease, Stanford University	Mar 11, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Feb 01, 2017	A variant of uncertain significance has been identified in the KCNH2 gene. The W927L variant has not been published as pathogenic or been reported as benign to our knowledge. Data from control individuals were not available to assess whether W927L may be a common benign variant in the general population. Nevertheless, the W927L variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. Finally, this substitution occurs at a position that is conserved in mammals and in silico analysis predicts this variant is probably damaging to the protein structure/function. -

Long QT syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Feb 05, 2024	This missense variant replaces tryptophan with leucine at codon 927 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 not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 10/162760 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	Oct 22, 2023	This sequence change replaces tryptophan, which is neutral and slightly polar, with leucine, which is neutral and non-polar, at codon 927 of the KCNH2 protein (p.Trp927Leu). 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: 200501). 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. 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. -

Long QT syndrome 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Aug 10, 2021

- -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jan 03, 2024

This missense variant replaces tryptophan with leucine at codon 927 of the KCNH2 protein. Computational prediction tools indicate that this variant's impact on protein structure and function is inconclusive. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with KCNH2-related disorders in the literature. This variant has been identified in 10/162760 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

Mar 06, 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.16

CADD

Uncertain

DANN

Benign

0.97

DEOGEN2

Uncertain

0.79

.;D

Eigen

Benign

-0.037

Eigen_PC

Benign

0.084

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.84

T;T

M_CAP

Pathogenic

0.87

MetaRNN

Uncertain

0.67

D;D

MetaSVM

Pathogenic

0.82

MutationAssessor

Benign

1.8

.;L

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.75

PROVEAN

Uncertain

-3.6

D;D

REVEL

Pathogenic

0.67

Sift

Benign

0.29

T;T

Sift4G

Benign

0.26

T;T

Polyphen

0.34

B;P

Vest4

0.54

MutPred

0.36

.;Gain of stability (P = 0.0182);

MVP

0.91

MPC

0.87

ClinPred

0.18

GERP RS

5.0

Varity_R

0.37

gMVP

0.56

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