NM_000238.4:c.2053C>T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM5PP2PP3_ModeratePP5

The NM_000238.4(KCNH2):c.2053C>T(p.Arg685Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,116 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 15/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R685H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 9.95

Publications

3 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_pathogenic. The variant received 6 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr7-150951012-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 979129.

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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.918

PP5

Variant 7-150951013-G-A is Pathogenic according to our data. Variant chr7-150951013-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 448974.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.2053C>T	p.Arg685Cys	missense_variant	Exon 8 of 15	ENST00000262186.10	NP_000229.1	Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10 link	c.2053C>T	p.Arg685Cys	missense_variant	Exon 8 of 15	1	NM_000238.4	ENSP00000262186.5		Q12809-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152250

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000964

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000796

AC:

AN:

251316

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.0000616

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:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727234

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112008

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.0000263

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74384

show subpopulations

African (AFR)

AF:

0.0000964

AC:

AN:

41476

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68038

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

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:

0.0000329

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Dec 02, 2024

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 cysteine, which is neutral and slightly polar, at codon 685 of the KCNH2 protein (p.Arg685Cys). 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: 448974). 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. -

Aug 28, 2023

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 cysteine at codon 685 of the KCNH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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 not been identified 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. -

Long QT syndrome 2

Pathogenic:1

May 24, 2017

Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

Nov 25, 2019

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The KCNH2 c.2053C>T; p.Arg685Cys variant (rs778135438), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 448974). This variant is only observed on three alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. The arginine at codon 685 is highly conserved, and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. Additionally, another variant at this codon (c.2054G>A; p.Arg685His) has been reported in individuals with long QT syndrome (Mullally 2013). However, due to limited information, the clinical significance of the p.Arg685Cys variant is uncertain at this time. References: Mullally J et al. Risk of life-threatening cardiac events among patients with long QT syndrome and multiple mutations. Heart Rhythm. 2013 Mar;10(3):378-82. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.96

CardioboostArm

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.41

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.95

.;D;D

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Uncertain

0.94

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Pathogenic

0.82

MetaRNN

Pathogenic

0.92

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.4

.;M;.

PhyloP100

9.9

PrimateAI

Pathogenic

0.91

PROVEAN

Pathogenic

-7.8

D;D;.

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

D;D;.

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;.

Vest4

0.95

MutPred

0.62

.;Loss of MoRF binding (P = 0.001);.;

MVP

0.97

MPC

2.5

ClinPred

1.0

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.86

gMVP

0.94

Mutation Taster

=12/88

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

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

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over