17-70176238-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2BP4_ModerateBS2

The NM_000891.3(KCNJ2):c.1199C>T(p.Thr400Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000508 in 1,613,976 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 Conflicting classifications of pathogenicity (no stars).

Frequency

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

Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

KCNJ2
NM_000891.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 4.95

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -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 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=0.117123395).

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 link	c.1199C>T	p.Thr400Met	missense_variant	Exon 2 of 2	ENST00000243457.4	NP_000882.1	P63252

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNJ2	ENST00000243457.4 link	c.1199C>T	p.Thr400Met	missense_variant	Exon 2 of 2	1	NM_000891.3	ENSP00000243457.2		P63252
KCNJ2	ENST00000535240.1 link	c.1199C>T	p.Thr400Met	missense_variant	Exon 2 of 2	1		ENSP00000441848.1		P63252

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000943

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000717

AC:

AN:

251044

Hom.:

AF XY:

0.0000811

AC XY:

AN XY:

135714

show subpopulations

Gnomad AFR exome

AF:

0.0000617

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.000277

Gnomad NFE exome

AF:

0.0000705

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000520

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.0000619

AC XY:

AN XY:

727230

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000812

Gnomad4 FIN exome

AF:

0.000187

Gnomad4 NFE exome

AF:

0.0000423

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74308

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000943

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000825

Hom.:

Bravo

AF:

0.0000453

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Sep 23, 2019

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 02, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in patients with sudden cardiac arrest and LQTS in the published literature (PMID: 21875779, 22944906, 28600387); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 25637381, 28600387, 22944906, 21875779) -

Jun 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3

Uncertain:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 400 of the KCNJ2 protein (p.Thr400Met). This variant is present in population databases (rs144022753, gnomAD 0.02%). This missense change has been observed in individual(s) with long QT syndrome and unexplained cardiac arrest (PMID: 21875779, 28600387, 35352813). ClinVar contains an entry for this variant (Variation ID: 161258). 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%. 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. -

Long QT syndrome

Uncertain:1

Jun 01, 2014

CSER _CC_NCGL, University of Washington

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: research

- -

Cardiovascular phenotype

Benign:1

Aug 28, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely 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

0.076

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Pathogenic

0.18

CADD

Uncertain

DANN

Uncertain

0.98

DEOGEN2

Benign

0.36

T;T

Eigen

Benign

0.053

Eigen_PC

Uncertain

0.28

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.86

.;D

M_CAP

Benign

0.077

MetaRNN

Benign

0.12

T;T

MetaSVM

Benign

-0.38

MutationAssessor

Benign

0.0

N;N

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-0.030

N;N

REVEL

Uncertain

0.41

Sift

Benign

0.13

T;T

Sift4G

Benign

0.19

T;T

Polyphen

0.025

B;B

Vest4

0.22

MVP

0.94

MPC

0.87

ClinPred

0.029

GERP RS

6.1

Varity_R

0.046

gMVP

0.41

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over