rs863224374

Positions:

• chr17-70176254-C-A
• chr17-70176254-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_000891.3(KCNJ2):​c.1215C>A​(p.Asp405Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNJ2 NM_000891.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.107

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

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNJ2. . Gene score misZ 2.7459 (greater than the threshold 3.09). Trascript score misZ 3.9347 (greater than threshold 3.09). GenCC has associacion of gene with 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=0.06267658).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNJ2	NM_000891.3	c.1215C>A	p.Asp405Glu	missense_variant	2/2	ENST00000243457.4	NP_000882.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNJ2	ENST00000243457.4	c.1215C>A	p.Asp405Glu	missense_variant	2/2	1	NM_000891.3	ENSP00000243457.2
KCNJ2	ENST00000535240.1	c.1215C>A	p.Asp405Glu	missense_variant	2/2	1		ENSP00000441848.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Andersen Tawil syndrome;C1865018:Short QT syndrome type 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 04, 2023

This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 405 of the KCNJ2 protein (p.Asp405Glu). This variant is not present in population databases (gnomAD no frequency). 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: 1373336). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.070
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	15
DANN	Benign	0.95
DEOGEN2	Benign	0.34	T;T
Eigen	Benign	-0.61
Eigen_PC	Benign	-0.43
FATHMM_MKL	Benign	0.71	D
LIST_S2	Benign	0.66	.;T
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.063	T;T
MetaSVM	Benign	-0.85	T
MutationAssessor	Benign	0.55	N;N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	0.20	N;N
REVEL	Benign	0.20
Sift	Benign	0.16	T;T
Sift4G	Benign	0.78	T;T
Polyphen		0.0	B;B
Vest4		0.070
MutPred		0.17		Gain of helix (P = 0.0496);Gain of helix (P = 0.0496);
MVP		0.51
MPC		0.77
ClinPred		0.26	T
GERP RS		1.9
Varity_R		0.069
gMVP		0.17

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: rs863224374; hg19: chr17-68172395;