Genetic Variant KCNH2:p.Arg164His (chr7-150958484-C-T) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PP3_StrongBS2_Supporting

The NM_000238.4(KCNH2):c.491G>A(p.Arg164His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000815 in 1,472,416 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 (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000086 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6O:1

Conservation

PhyloP100: 2.99

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 3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.955

BS2

High AC in GnomAd4 at 6 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 rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.491G>A	p.Arg164His	missense_variant	Exon 4 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.491G>A	p.Arg164His	missense_variant	Exon 4 of 15	1	NM_000238.4	ENSP00000262186.5	Q12809-1
KCNH2	ENST00000532957.5 link	n.714G>A		non_coding_transcript_exon_variant	Exon 4 of 9	2
KCNH2	ENST00000684241.1 link	n.1324G>A		non_coding_transcript_exon_variant	Exon 2 of 13

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.00

GnomAD4 exome

AF:

0.0000863

AC:

114

AN:

1320276

Hom.:

Cov.:

AF XY:

0.0000814

AC XY:

AN XY:

650884

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:

0.000108

Gnomad4 OTH exome

AF:

0.0000183

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152140

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

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:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000378

ExAC

AF:

0.0000423

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome 2

Uncertain:2

Jul 01, 2015

Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 31, 2018

SIB Swiss Institute of Bioinformatics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

This variant is interpreted as a Uncertain Significance - Insufficient Evidence, for Long QT syndrome 2, in Autosomal Dominant manner. The following ACMG Tag(s) were applied: PM2-Supporting => PM2 downgraded in strength to Supporting. -

not provided

Uncertain:1

Jan 06, 2022

AiLife Diagnostics, AiLife Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome

Uncertain:1

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 164 of the KCNH2 protein (p.Arg164His). 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 individuals with long QT syndrome (PMID: 19716085, 22429796; internal data). ClinVar contains an entry for this variant (Variation ID: 67508). 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. -

Cardiovascular phenotype

Uncertain:1

Oct 31, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.491G>A (p.R164H) alteration is located in exon 4 (coding exon 4) of the KCNH2 gene. This alteration results from a G to A substitution at nucleotide position 491, causing the arginine (R) at amino acid position 164 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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

Uncertain:1

Oct 02, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital long QT syndrome

Other:1

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:19716085;PMID:22429796). 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

0.14

BayesDel_addAF

Pathogenic

0.32

BayesDel_noAF

Pathogenic

0.22

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.50

Eigen

Benign

-0.019

Eigen_PC

Benign

0.079

FATHMM_MKL

Uncertain

0.77

LIST_S2

Uncertain

0.86

M_CAP

Pathogenic

0.74

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

1.2

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-2.1

REVEL

Pathogenic

0.76

Sift

Benign

0.47

Sift4G

Benign

0.57

Polyphen

0.57

Vest4

0.66

MutPred

0.88

Loss of solvent accessibility (P = 0.0079);

MVP

0.99

MPC

2.3

ClinPred

0.56

GERP RS

3.9

Varity_R

0.081

gMVP

0.49

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