rs766143485

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 1P and 6B. PP2BP4_ModerateBS2

The NM_000891.3(KCNJ2):​c.119G>A​(p.Arg40Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,614,054 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign 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. R40L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

KCNJ2
NM_000891.3 missense

Scores

1
4
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:1

Conservation

PhyloP100: 6.84

Publications

5 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

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.
BP4
Computational evidence support a benign effect (MetaRNN=0.25481462).
BS2
High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNJ2NM_000891.3 linkc.119G>A p.Arg40Gln missense_variant Exon 2 of 2 ENST00000243457.4 NP_000882.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNJ2ENST00000243457.4 linkc.119G>A p.Arg40Gln missense_variant Exon 2 of 2 1 NM_000891.3 ENSP00000243457.2
KCNJ2ENST00000535240.1 linkc.119G>A p.Arg40Gln missense_variant Exon 2 of 2 1 ENSP00000441848.1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251464
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000294
AC:
43
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86256
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000351
AC:
39
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.0000966
AC:
4
AN:
41418
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000712
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:8Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Mar 08, 2022
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The KCNJ2 c.119G>A; p.Arg40Gln variant (rs766143485) is reported in the literature in an individual affected with fetal thrombotic vasculopathy (Munroe 2018), and an individual affected with primary electrical disease who also carried a pathogenic PKP2 variant (Proost 2017). This variant is also reported in ClinVar (Variation ID: 324830), but is only observed on five alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. The arginine at codon 40 is moderately conserved, and computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.201). In vitro functional analyses demonstrate reduced channel function (Munroe 2018). However, given the limited clinical and functional data, the significance of this variant is uncertain at this time. References: Munroe PB et al. Postmortem Genetic Testing for Cardiac Ion Channelopathies in Stillbirths. Circ Genom Precis Med. 2018 Jan;11(1):e001817. PMID: 29874177. Proost D et al. Targeted Next-Generation Sequencing of 51 Genes Involved in Primary Electrical Disease. J Mol Diagn. 2017 May;19(3):445-459. PMID: 28341588. -

Jun 16, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Has been reported as a likely benign variant in one patient with primary electrical disease who also harbors a loss of function variant in the PKP2 gene (PMID: 28341588); Has also been observed in a family with arrhythmogenic cardiomyopathy who harbored a different PKP2 variant; the KCNJ2 variant listed as possibly not assocaited with disease in this family (PMID: 37510372); Has also been observed in cases of stillbirth or sudden unexpected death in a pediatric setting (PMID: 29874177, 35027292); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis suggests that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 29874177, 35027292, 28341588, 37510372) -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3;C3151431:Atrial fibrillation, familial, 9 Uncertain:1
Aug 31, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

SUDDEN INFANT DEATH SYNDROME Uncertain:1
Oct 01, 2021
Robert's Program, Boston Children's Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

We classify this variant as a variant of uncertain significance using ACMG/AMP criteria. As this variant has functional evidence supporting pathogenicty, we suspect this variant is favoring pathogenic. -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3 Uncertain:1
Jan 29, 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 40 of the KCNJ2 protein (p.Arg40Gln). This variant is present in population databases (rs766143485, gnomAD 0.008%). This missense change has been observed in individual(s) with primary electrical disease (PED), however this individual also had a pathogenic variant in another PED-related gene (PMID: 28341588, 29874177). ClinVar contains an entry for this variant (Variation ID: 324830). 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: 29874177). 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. -

Atrial fibrillation, familial, 9 Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Andersen Tawil syndrome Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Short QT syndrome type 3 Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Cardiovascular phenotype Benign:1
Nov 22, 2023
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Benign
-0.26
CADD
Uncertain
26
DANN
Uncertain
1.0
DEOGEN2
Benign
0.37
T;T
Eigen
Benign
0.077
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.90
.;D
M_CAP
Benign
0.023
T
MetaRNN
Benign
0.25
T;T
MetaSVM
Benign
-0.93
T
MutationAssessor
Benign
1.8
L;L
PhyloP100
6.8
PrimateAI
Uncertain
0.79
T
PROVEAN
Benign
-0.79
N;N
REVEL
Benign
0.20
Sift
Benign
0.059
T;T
Sift4G
Benign
0.093
T;T
Polyphen
0.18
B;B
Vest4
0.56
MutPred
0.72
Loss of MoRF binding (P = 0.0659);Loss of MoRF binding (P = 0.0659);
MVP
0.68
MPC
0.96
ClinPred
0.17
T
GERP RS
5.7
Varity_R
0.14
gMVP
0.89
Mutation Taster
=63/37
polymorphism

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

Other links and lift over

dbSNP: rs766143485; hg19: chr17-68171299; API