dbSNP rs199472874: KCNH2:p.Arg252Trp (chr7-150958221-G-A) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

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

The NM_000238.4(KCNH2):c.754C>T(p.Arg252Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,371,584 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.14

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 14 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.754C>T	p.Arg252Trp	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.754C>T	p.Arg252Trp	missense_variant	Exon 4 of 15	1	NM_000238.4	ENSP00000262186.5	Q12809-1
KCNH2	ENST00000532957.5 link	n.977C>T		non_coding_transcript_exon_variant	Exon 4 of 9	2
KCNH2	ENST00000684241.1 link	n.1587C>T		non_coding_transcript_exon_variant	Exon 2 of 13

Frequencies

GnomAD3 genomes

AF:

0.00000659

AC:

AN:

151846

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000115

AC:

AN:

1219738

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

594704

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:

0.0000130

Gnomad4 OTH exome

AF:

0.0000200

GnomAD4 genome

AF:

0.00000659

AC:

AN:

151846

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74182

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:1

Aug 18, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine with tryptophan at codon 252 of the KCNH2 protein (p.Arg252Trp). The arginine residue is weakly conserved and there is a moderate physicochemical difference between arginine and tryptophan. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Uncertain

0.020

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.53

D;T

Eigen

Benign

-0.36

Eigen_PC

Benign

-0.56

FATHMM_MKL

Benign

0.15

LIST_S2

Uncertain

0.87

D;D

M_CAP

Pathogenic

0.86

MetaRNN

Uncertain

0.48

T;T

MetaSVM

Uncertain

0.55

MutationAssessor

Benign

0.69

N;.

PrimateAI

Pathogenic

0.89

PROVEAN

Benign

-2.1

N;.

REVEL

Uncertain

0.49

Sift

Uncertain

0.0030

D;.

Sift4G

Uncertain

0.019

D;D

Polyphen

1.0

D;.

Vest4

0.38

MutPred

0.47

Loss of methylation at R252 (P = 0.0085);.;

MVP

0.89

MPC

2.1

ClinPred

0.67

GERP RS

1.3

Varity_R

0.043

gMVP

0.52

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