Genetic Variant KCNH2:p.Arg1033Gln (chr7-150947382-C-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 3P and 6B. PM1PP2BP4_ModerateBS2

The NM_000238.4(KCNH2):c.3098G>A(p.Arg1033Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000226 in 1,548,478 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1033W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.00

Publications

1 publications found

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 Gene-Disease associations (from GenCC):

long QT syndrome
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
long QT syndrome 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
short QT syndrome
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
short QT syndrome type 1
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
Brugada syndrome
Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

KCNH2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 27 uncertain in NM_000238.4

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.4846 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.

BP4

Computational evidence support a benign effect (MetaRNN=0.25370747).

BS2

High AC in GnomAdExome4 at 32 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000238.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNH2	NM_000238.4	MANE Select	c.3098G>A	p.Arg1033Gln	missense	Exon 13 of 15	NP_000229.1
KCNH2	NM_001406753.1		c.2810G>A	p.Arg937Gln	missense	Exon 11 of 13	NP_001393682.1
KCNH2	NM_172057.3		c.2078G>A	p.Arg693Gln	missense	Exon 9 of 11	NP_742054.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNH2	ENST00000262186.10	TSL:1 MANE Select	c.3098G>A	p.Arg1033Gln	missense	Exon 13 of 15	ENSP00000262186.5
KCNH2	ENST00000330883.9	TSL:1	c.2078G>A	p.Arg693Gln	missense	Exon 9 of 11	ENSP00000328531.4
KCNH2	ENST00000713710.1		c.3032G>A	p.Arg1011Gln	missense	Exon 13 of 15	ENSP00000519013.1

Frequencies

GnomAD3 genomes

AF:

0.0000198

AC:

AN:

151894

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000484

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000686

AC:

AN:

145876

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000229

AC:

AN:

1396584

Hom.:

Cov.:

AF XY:

0.0000203

AC XY:

AN XY:

688892

show subpopulations

African (AFR)

AF:

0.000126

AC:

AN:

31726

American (AMR)

AF:

0.00

AC:

AN:

35674

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25110

East Asian (EAS)

AF:

0.00

AC:

AN:

35970

South Asian (SAS)

AF:

0.0000126

AC:

AN:

79192

European-Finnish (FIN)

AF:

0.00

AC:

AN:

46696

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5236

European-Non Finnish (NFE)

AF:

0.0000232

AC:

AN:

1079084

Other (OTH)

AF:

0.0000345

AC:

AN:

57896

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.464

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000198

AC:

AN:

151894

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74206

show subpopulations

African (AFR)

AF:

0.0000484

AC:

AN:

41360

American (AMR)

AF:

0.0000655

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5124

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67924

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.592

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000102

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Sep 23, 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 arginine with glutamine at codon 1033 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 1/145876 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.

Jan 16, 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 glutamine, which is neutral and polar, at codon 1033 of the KCNH2 protein (p.Arg1033Gln). 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: 456920). 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:1

Dec 31, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Identified in a cohort of patients with HCM in published literature (PMID: 31199839); This variant is associated with the following publications: (PMID: 31199839)

Cardiovascular phenotype

Uncertain:1

May 03, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R1033Q variant (also known as c.3098G>A), located in coding exon 13 of the KCNH2 gene, results from a G to A substitution at nucleotide position 3098. The arginine at codon 1033 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear.

Cardiac arrhythmia

Uncertain:1

Mar 06, 2024

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces arginine with glutamine at codon 1033 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 KCNH2-related disorders in the literature. This variant has been identified in 1/145876 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 v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.071

CardioboostArm

Benign

0.000033

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Uncertain

0.050

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.34

Eigen

Benign

-0.39

Eigen_PC

Benign

-0.28

FATHMM_MKL

Benign

0.30

LIST_S2

Uncertain

0.91

M_CAP

Pathogenic

0.50

MetaRNN

Benign

0.25

MetaSVM

Uncertain

0.72

MutationAssessor

Benign

0.95

PhyloP100

1.0

PrimateAI

Uncertain

0.60

PROVEAN

Benign

-0.89

REVEL

Uncertain

0.60

Sift

Benign

0.30

Sift4G

Benign

0.54

Polyphen

0.017

Vest4

0.27

MutPred

0.29

Loss of MoRF binding (P = 0.0658)

MVP

0.85

MPC

0.67

ClinPred

0.65

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

3.2

Varity_R

0.18

gMVP

0.43

Mutation Taster

=80/20

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over