rs766143485

Variant names:

• chr17-70175158-G-A
• rs766143485
• NM_000891.3:c.119G>A

Your query was ambiguous. Multiple possible variants found:

• chr17-70175158-G-A
• chr17-70175158-G-C
• chr17-70175158-G-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 3P and 6B. PM1 PP2 BP4_Moderate BS2

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. 13/23 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
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:1
• Conservation: PhyloP100: 6.84

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]

ACMG classification

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

• PM1: In a topological_domain Cytoplasmic (size 79) in uniprot entity KCNJ2_HUMAN there are 30 pathogenic changes around while only 4 benign (88%) 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 long QT syndrome, short QT syndrome, Andersen-Tawil syndrome, familial atrial fibrillation, short QT syndrome type 3, catecholaminergic polymorphic ventricular tachycardia.
• 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
KCNJ2	NM_000891.3	c.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
KCNJ2	ENST00000243457.4	c.119G>A	p.Arg40Gln	missense_variant	Exon 2 of 2	1	NM_000891.3	ENSP00000243457.2
KCNJ2	ENST00000535240.1	c.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

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

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

Gnomad4 AFR exome AF: 0.0000299 AC: 1 AN: 33480

Gnomad4 AMR exome AF: 0.00 AC: 0 AN: 44724

Gnomad4 ASJ exome AF: 0.00 AC: 0 AN: 26136

Gnomad4 EAS exome AF: 0.00 AC: 0 AN: 39700

Gnomad4 SAS exome AF: 0.0000232 AC: 2 AN: 86256

Gnomad4 FIN exome AF: 0.0000187 AC: 1 AN: 53420

Gnomad4 NFE exome AF: 0.0000351 AC: 39 AN: 1112012

Gnomad4 Remaining exome AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152162 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74338

Gnomad4 AFR AF: 0.0000966 AC: 0.0000965764 AN: 0.0000965764

Gnomad4 AMR AF: 0.00 AC: 0 AN: 0

Gnomad4 ASJ AF: 0.00 AC: 0 AN: 0

Gnomad4 EAS AF: 0.00 AC: 0 AN: 0

Gnomad4 SAS AF: 0.000207 AC: 0.000207297 AN: 0.000207297

Gnomad4 FIN AF: 0.00 AC: 0 AN: 0

Gnomad4 NFE AF: 0.0000147 AC: 0.0000146985 AN: 0.0000146985

Gnomad4 OTH AF: 0.00 AC: 0 AN: 0

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:8 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

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) -

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. -

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
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

LitVar

Other links and lift over

dbSNP: rs766143485; hg19: chr17-68171299;