rs754883792

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4BS1_SupportingBS2

The NM_000238.4(KCNH2):c.3448C>A(p.Leu1150Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000221 in 1,587,108 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

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

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 2.23

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 -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.3292657).

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000237 (34/1434894) while in subpopulation MID AF= 0.00459 (25/5448). AF 95% confidence interval is 0.00319. There are 0 homozygotes in gnomad4_exome. There are 21 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAdExome4 at 34 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.3448C>A	p.Leu1150Met	missense_variant	Exon 15 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.3448C>A	p.Leu1150Met	missense_variant	Exon 15 of 15	1	NM_000238.4	ENSP00000262186.5	Q12809-1
KCNH2	ENST00000330883.9 link	c.2428C>A	p.Leu810Met	missense_variant	Exon 11 of 11	1		ENSP00000328531.4	Q12809-2
KCNH2	ENST00000684241.1 link	n.4281C>A		non_coding_transcript_exon_variant	Exon 13 of 13

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152214

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

GnomAD3 exomes

AF:

0.0000551

AC:

AN:

199644

Hom.:

AF XY:

0.0000925

AC XY:

AN XY:

108142

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000111

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000388

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000353

Gnomad OTH exome

AF:

0.00117

GnomAD4 exome

AF:

0.0000237

AC:

AN:

1434894

Hom.:

Cov.:

AF XY:

0.0000295

AC XY:

AN XY:

711284

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:

0.0000365

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000273

Gnomad4 OTH exome

AF:

0.0000506

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74370

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

Alfa

AF:

0.000528

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000750

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Aug 13, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces leucine with methionine at codon 1150 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 11/199644 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. -

Dec 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1150 of the KCNH2 protein (p.Leu1150Met). This variant is present in population databases (rs754883792, gnomAD 0.005%). 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: 456931). 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. -

not provided

Uncertain:1Benign:1

Jan 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

KCNH2: BS1 -

Sep 09, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in one stillborn male without congenital malformations or chromosomal abnormalities in published literature (Sahlin et al., 2019), although at least one other variant in a different gene was also identified and no segregation studies were described; Reported in ClinVar as a variant of uncertain significance but additional evidence is not available (ClinVar Variant ID 456931; Landrum et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 30615648) -

Cardiovascular phenotype

Uncertain:1

Jun 17, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L1150M variant (also known as c.3448C>A), located in coding exon 15 of the KCNH2 gene, results from a C to A substitution at nucleotide position 3448. The leucine at codon 1150 is replaced by methionine, an amino acid with highly similar properties, and is located in the cytoplasmic C-terminal region. This amino acid position is highly 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. -

KCNH2-related disorder

Uncertain:1

Mar 14, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The KCNH2 c.3448C>A variant is predicted to result in the amino acid substitution p.Leu1150Met. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.011% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Cardiac arrhythmia

Uncertain:1

Jul 17, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces leucine with methionine at codon 1150 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 been reported in a fetus affected with stillbirth (PMID: 30615648). This variant has been identified in 11/199644 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

Benign

0.13

BayesDel_addAF

Uncertain

0.092

BayesDel_noAF

Uncertain

0.030

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.40

.;T

Eigen

Benign

0.15

Eigen_PC

Benign

0.15

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.76

T;T

M_CAP

Pathogenic

0.29

MetaRNN

Benign

0.33

T;T

MetaSVM

Pathogenic

0.90

MutationAssessor

Benign

1.5

.;L

PrimateAI

Uncertain

0.70

PROVEAN

Benign

-0.61

N;N

REVEL

Uncertain

0.55

Sift

Uncertain

0.024

D;D

Sift4G

Benign

0.15

T;T

Polyphen

0.98

D;D

Vest4

0.31

MutPred

0.19

.;Gain of MoRF binding (P = 0.1565);

MVP

0.66

MPC

0.66

ClinPred

0.14

GERP RS

3.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.11

gMVP

0.15

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