rs199473028

Variant summary

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

The NM_000238.4(KCNH2):c.3224C>T(p.Pro1075Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000422 in 1,610,422 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1075Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000043 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5O:1

Conservation

PhyloP100: 4.60

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 GnomAd at 6 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH2	NM_000238.4 linkuse as main transcript	c.3224C>T	p.Pro1075Leu	missense_variant	14/15	ENST00000262186.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH2	ENST00000262186.10 linkuse as main transcript	c.3224C>T	p.Pro1075Leu	missense_variant	14/15	1	NM_000238.4	P1	Q12809-1
KCNH2	ENST00000330883.9 linkuse as main transcript	c.2204C>T	p.Pro735Leu	missense_variant	10/11	1			Q12809-2
KCNH2	ENST00000684241.1 linkuse as main transcript	n.4057C>T		non_coding_transcript_exon_variant	12/13

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152120

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000200

AC:

AN:

249490

Hom.:

AF XY:

0.00000742

AC XY:

AN XY:

134852

show subpopulations

Gnomad AFR exome

AF:

0.000124

Gnomad AMR exome

AF:

0.0000291

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:

0.0000178

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000425

AC:

AN:

1458184

Hom.:

Cov.:

AF XY:

0.0000469

AC XY:

AN XY:

724788

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:

0.0000698

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000496

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152238

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74430

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.0000653

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000357

Hom.:

Bravo

AF:

0.0000453

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 19, 2024	This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1075 of the KCNH2 protein (p.Pro1075Leu). This variant is present in population databases (rs199473028, gnomAD 0.01%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 17905336). ClinVar contains an entry for this variant (Variation ID: 67481). 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. Experimental studies have shown that this missense change affects KCNH2 function (PMID: 31557540). 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, no assertion criteria provided	research	CSER _CC_NCGL, University of Washington	Jun 01, 2014	- -

Long QT syndrome 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 13, 2020

The c.3224C>T (p.P1075L) alteration is located in exon 14 (coding exon 14) of the KCNH2 gene. This alteration results from a C to T substitution at nucleotide position 3224, causing the proline (P) at amino acid position 1075 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 08, 2023

This missense variant replaces proline with leucine at codon 1075 of the KCNH2 protein. This variant is found within a highly conserved region in the C-terminal cytoplasmic domain (a.a. 843-1159). Rare non-truncating variants in this region have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). This variant has been shown to cause reduced channel current and accelerated rates of deactivation in a functional study with HEK293 cells (PMID: 31557540), while has also been shown to have no impact on channel current in another in vitro study (PMID: 34930020). This variant has been reported in two individuals affected with long QT syndrome (PMID: 17905336, 20850565), in an individual affected with complete atrioventricular block and torsades de pointes (PMID: 20386770), in an individual suspected of having epilepsy (PMID: 31696929), and in three individuals without arrhythmia (PMID: 34930020). This variant has been identified in 5/249490 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion for a pathogenic role, 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. -

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:17905336). 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

Pathogenic

0.61

CardioboostArm

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Pathogenic

0.26

Cadd

Pathogenic

Dann

Uncertain

1.0

Eigen

Benign

0.14

Eigen_PC

Uncertain

0.22

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.68

MetaRNN

Uncertain

0.70

D;D

MetaSVM

Pathogenic

0.83

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.78

PROVEAN

Pathogenic

-6.6

D;D

REVEL

Pathogenic

0.79

Sift

Uncertain

0.0020

D;D

Sift4G

Uncertain

0.0060

D;D

Polyphen

0.33

B;B

Vest4

0.68

MVP

0.94

MPC

0.69

ClinPred

0.76

GERP RS

4.0

Varity_R

0.49

gMVP

0.69

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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