chr7-150947362-T-C

Variant names:

Variant summary

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

The NM_000238.4(KCNH2):c.3118A>G(p.Ser1040Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000776 in 1,545,762 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. S1040N) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000079 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.0800

Publications

7 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 4 benign, 28 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=0.2440578).

BS2

High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4 link	c.3118A>G	p.Ser1040Gly	missense_variant	Exon 13 of 15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10 link	c.3118A>G	p.Ser1040Gly	missense_variant	Exon 13 of 15	1	NM_000238.4	ENSP00000262186.5

Frequencies

GnomAD3 genomes

AF:

0.00000660

AC:

AN:

151450

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

GnomAD2 exomes

AF:

0.00

AC:

AN:

144714

AF XY:

0.00

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000789

AC:

AN:

1394312

Hom.:

Cov.:

AF XY:

0.0000116

AC XY:

AN XY:

687846

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

31656

American (AMR)

AF:

0.00

AC:

AN:

35684

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25130

East Asian (EAS)

AF:

0.00

AC:

AN:

35872

South Asian (SAS)

AF:

0.0000126

AC:

AN:

79150

European-Finnish (FIN)

AF:

0.00

AC:

AN:

44656

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5224

European-Non Finnish (NFE)

AF:

0.00000927

AC:

AN:

1079048

Other (OTH)

AF:

0.00

AC:

AN:

57892

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.484

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:

0.00000660

AC:

AN:

151450

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73912

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41206

American (AMR)

AF:

0.00

AC:

AN:

15238

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5056

South Asian (SAS)

AF:

0.00

AC:

AN:

4796

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10554

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67830

Other (OTH)

AF:

0.00

AC:

AN:

2078

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000284

Hom.:

ExAC

AF:

0.0000414

AC:

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

Apr 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with glycine, which is neutral and non-polar, at codon 1040 of the KCNH2 protein (p.Ser1040Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of long QT syndrome and/or sudden infant death syndrome (PMID: 17210839, 30369311). ClinVar contains an entry for this variant (Variation ID: 67472). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Experimental studies have shown that this missense change does not substantially affect KCNH2 function (PMID: 18222468). 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 06, 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 serine with glycine at codon 1040 of the KCNH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). A functional study has shown that the mutant channel is biophysically similar to the wild-type channel (PMID: 18222468). This variant has been reported in an individual affected with sudden infant death syndrome (PMID: 17210839), and in a few individuals with QT prolongation (PMID: 30369311). 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. -

Cardiovascular phenotype

Uncertain:1

Feb 19, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.3118A>G (p.S1040G) alteration is located in exon 13 (coding exon 13) of the KCNH2 gene. This alteration results from a A to G substitution at nucleotide position 3118, causing the serine (S) at amino acid position 1040 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Short QT syndrome type 1;C3150943:Long QT syndrome 2

Uncertain:1

Jul 28, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiac arrhythmia

Uncertain:1

May 14, 2024

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

SUDDEN INFANT DEATH SYNDROME

Other:1

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

This variant has been reported as associated with Sudden infant death syndrome in the following publications (PMID:17210839). 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

Benign

0.056

CardioboostArm

Benign

1.5e-7

BayesDel_addAF

Uncertain

0.093

BayesDel_noAF

Benign

-0.10

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.56

.;D

Eigen

Benign

-0.62

Eigen_PC

Benign

-0.51

FATHMM_MKL

Benign

0.29

LIST_S2

Benign

0.56

T;T

M_CAP

Benign

0.056

MetaRNN

Benign

0.24

T;T

MetaSVM

Benign

-0.62

MutationAssessor

Benign

1.3

.;L

PhyloP100

0.080

PrimateAI

Uncertain

0.56

PROVEAN

Uncertain

-2.5

N;N

REVEL

Uncertain

0.48

Sift

Benign

0.037

D;D

Sift4G

Benign

0.26

T;T

Polyphen

0.0020

B;B

Vest4

0.32

MutPred

0.74

.;Loss of phosphorylation at S1040 (P = 0.0163);

MVP

0.98

MPC

0.15

ClinPred

0.54

GERP RS

2.6

Varity_R

0.15

gMVP

0.46

Mutation Taster

=7/93

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over