17-70176244-C-T

Variant summary

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

The NM_000891.3(KCNJ2):c.1205C>T(p.Thr402Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000471 in 1,613,986 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. T402T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

KCNJ2
NM_000891.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.13

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 where missense usually causes diseases, KCNJ2

BP4

Computational evidence support a benign effect (MetaRNN=0.09744415).

BS2

High AC in GnomAdExome at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNJ2	NM_000891.3 linkuse as main transcript	c.1205C>T	p.Thr402Met	missense_variant	2/2	ENST00000243457.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNJ2	ENST00000243457.4 linkuse as main transcript	c.1205C>T	p.Thr402Met	missense_variant	2/2	1	NM_000891.3	P1
KCNJ2	ENST00000535240.1 linkuse as main transcript	c.1205C>T	p.Thr402Met	missense_variant	2/2	1		P1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152144

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000438

AC:

AN:

251066

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135724

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000654

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000493

AC:

AN:

1461842

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

727230

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000157

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000531

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152144

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74320

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000658

Hom.:

Bravo

AF:

0.0000718

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Apr 10, 2017

- -

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 27, 2023

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 402 of the KCNJ2 protein (p.Thr402Met). This variant is present in population databases (rs759070406, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with KCNJ2-related conditions. ClinVar contains an entry for this variant (Variation ID: 518798). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬†is likely to be tolerated. 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. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 14, 2022

The p.T402M variant (also known as c.1205C>T), located in coding exon 1 of the KCNJ2 gene, results from a C to T substitution at nucleotide position 1205. The threonine at codon 402 is replaced by methionine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species, and methionine 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 variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.073

BayesDel_addAF

Benign

-0.22

BayesDel_noAF

Benign

-0.28

Cadd

Uncertain

Dann

Benign

0.93

DEOGEN2

Benign

0.35

T;T

Eigen

Benign

-0.068

Eigen_PC

Benign

0.16

FATHMM_MKL

Uncertain

0.86

M_CAP

Benign

0.031

MetaRNN

Benign

0.097

T;T

MetaSVM

Benign

-0.33

MutationAssessor

Benign

1.1

L;L

MutationTaster

Benign

0.79

D;D

PrimateAI

Benign

0.42

PROVEAN

Benign

0.030

N;N

REVEL

Benign

0.29

Sift

Benign

0.26

T;T

Sift4G

Benign

0.17

T;T

Polyphen

0.0020

B;B

Vest4

0.15

MVP

0.63

MPC

0.86

ClinPred

0.045

GERP RS

6.1

Varity_R

0.039

gMVP

0.22

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