rs199473650

Positions:

• chr17-70175200-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The NM_000891.3(KCNJ2):​c.161G>T​(p.Cys54Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C54G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNJ2 NM_000891.3 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 10.0

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_pathogenic. Variant got 8 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 17-70175200-G-T is Pathogenic according to our data. Variant chr17-70175200-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 30119.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr17-70175200-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNJ2	NM_000891.3	c.161G>T	p.Cys54Phe	missense_variant	2/2	ENST00000243457.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNJ2	ENST00000243457.4	c.161G>T	p.Cys54Phe	missense_variant	2/2	1	NM_000891.3	P1
KCNJ2	ENST00000535240.1	c.161G>T	p.Cys54Phe	missense_variant	2/2	1		P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Andersen Tawil syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Apr 15, 2007

- -

Familial periodic paralysis Other:1

not provided, no classification provided

literature only

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

-

This variant has been reported as associated with Periodic paralysis in the following publications (PMID:17324964;PMID:19201608). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.97	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	.;D
M_CAP	Pathogenic	0.71	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-10	D;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.022	D;D
Polyphen		1.0	D;D
Vest4		0.98
MutPred		0.88		Gain of MoRF binding (P = 0.0786);Gain of MoRF binding (P = 0.0786);
MVP		0.99
MPC		2.4
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.98
gMVP		0.99

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: rs199473650; hg19: chr17-68171341;