NM_000891.3:c.953A>G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM1PP2BS2

The NM_000891.3(KCNJ2):c.953A>G(p.Asn318Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,613,888 control chromosomes in the GnomAD database, with no homozygous occurrence. 14/22 in silico tools predict 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. N318Y) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

KCNJ2
NM_000891.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7O:1

Conservation

PhyloP100: 3.05

Publications

6 publications found

Variant links:

Genes affected

KCNJ2 (HGNC:6263): (potassium inwardly rectifying channel subfamily J member 2) Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Mutations in this gene have been associated with Andersen syndrome, which is characterized by periodic paralysis, cardiac arrhythmias, and dysmorphic features. [provided by RefSeq, Jul 2008]

KCNJ2 Gene-Disease associations (from GenCC):

Andersen-Tawil syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P, Labcorp Genetics (formerly Invitae)
short QT syndrome type 3
Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Labcorp Genetics (formerly Invitae)
short QT syndrome
Inheritance: AD Classification: MODERATE, SUPPORTIVE Submitted by: ClinGen, Orphanet
familial atrial fibrillation
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
catecholaminergic polymorphic ventricular tachycardia
Inheritance: AD Classification: LIMITED, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp
long QT syndrome
Inheritance: AD Classification: LIMITED Submitted by: ClinGen

KCNJ2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000891.3

PP2

Missense variant in the KCNJ2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 51 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 2.7459 (below the threshold of 3.09). Trascript score misZ: 3.9347 (above the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 3, short QT syndrome, Andersen-Tawil syndrome, familial atrial fibrillation, catecholaminergic polymorphic ventricular tachycardia, long QT syndrome.

BS2

High AC in GnomAdExome4 at 27 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNJ2	NM_000891.3 link	c.953A>G	p.Asn318Ser	missense_variant	Exon 2 of 2	ENST00000243457.4	NP_000882.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNJ2	ENST00000243457.4 link	c.953A>G	p.Asn318Ser	missense_variant	Exon 2 of 2	1	NM_000891.3	ENSP00000243457.2
KCNJ2	ENST00000535240.1 link	c.953A>G	p.Asn318Ser	missense_variant	Exon 2 of 2	1		ENSP00000441848.1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152006

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000278

AC:

AN:

251354

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000185

AC:

AN:

1461882

Hom.:

Cov.:

AF XY:

0.0000193

AC XY:

AN XY:

727242

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000447

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:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000225

AC:

AN:

1112002

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.490

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:

0.0000132

AC:

AN:

152006

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74230

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41376

American (AMR)

AF:

0.0000655

AC:

AN:

15262

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5166

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68000

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

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:

0.0000272

Hom.:

Bravo

AF:

0.0000302

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Andersen Tawil syndrome

Uncertain:3Other:1

Jan 08, 2020

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 07, 2019

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was classified as: Uncertain significance. The available evidence on this variant's pathogenicity is insufficient or conflicting. The following ACMG criteria were applied in classifying this variant: No criteria apply. -

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

- -

Jun 01, 2014

CSER _CC_NCGL, University of Washington

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:research

- -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3;C3151431:Atrial fibrillation, familial, 9

Uncertain:1

Sep 28, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3

Uncertain:1

Nov 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 318 of the KCNJ2 protein (p.Asn318Ser). This variant is present in population databases (rs367560052, gnomAD 0.009%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 23644778). ClinVar contains an entry for this variant (Variation ID: 161257). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt KCNJ2 protein function with a negative predictive value of 95%. Experimental studies have shown that this missense change affects KCNJ2 function (PMID: 23644778). 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

Jun 14, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Jul 15, 2019

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.N318S variant (also known as c.953A>G), located in coding exon 1 of the KCNJ2 gene, results from an A to G substitution at nucleotide position 953. The asparagine at codon 318 is replaced by serine, an amino acid with highly similar properties. This variant was identified in an individual with ventricular fibrillation (Limberg MM et al. Basic Res. Cardiol., 2013 May;108:353). In addition, this variant has been reported in a hypertrophic cardiomyopathy (HCM) cohort; however, clinical details were limited (Lopes LR et al. Heart, 2015 Feb;101:294-301). This amino acid position is not well conserved in available vertebrate species, and serine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.051

BayesDel_addAF

Benign

-0.28

BayesDel_noAF

Benign

-0.44

CADD

Benign

(source)

DANN

Benign

0.16

DEOGEN2

Uncertain

0.54

D;D

Eigen

Benign

-0.43

Eigen_PC

Benign

-0.16

FATHMM_MKL

Uncertain

0.85

LIST_S2

Uncertain

0.87

.;D

M_CAP

Pathogenic

0.56

MetaRNN

Uncertain

0.50

D;D

MetaSVM

Benign

-0.50

MutationAssessor

Benign

-1.3

N;N

PhyloP100

3.0

PrimateAI

Uncertain

0.57

PROVEAN

Benign

0.13

N;N

REVEL

Benign

0.26

Sift

Benign

1.0

T;T

Sift4G

Benign

1.0

T;T

Polyphen

0.0

B;B

Vest4

0.71

MVP

0.46

MPC

0.66

ClinPred

0.053

GERP RS

5.8

Varity_R

0.076

gMVP

0.35

Mutation Taster

=9/91

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

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over