NM_004366.6:c.2386C>T

Variant names:

• chr3-184352042-G-A
• rs376823689
• NM_004366.6:c.2386C>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_004366.6(CLCN2):​c.2386C>T​(p.Gln796*) variant causes a stop gained 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. Variant has been reported in ClinVar as Likely pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CLCN2 NM_004366.6 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 9.95
• Publications: 1 publications found

Genes affected

CLCN2 (HGNC:2020): (chloride voltage-gated channel 2) This gene encodes a voltage-gated chloride channel. The encoded protein is a transmembrane protein that maintains chloride ion homeostasis in various cells. Defects in this gene may be a cause of certain epilepsies. Four transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2012]

CLCN2 Gene-Disease associations (from GenCC):

• leukoencephalopathy with mild cerebellar ataxia and white matter edema

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
• epilepsy, idiopathic generalized, susceptibility to, 11

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• familial hyperaldosteronism type II

  Inheritance: AD Classification: MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• epilepsy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-184352042-G-A is Pathogenic according to our data. Variant chr3-184352042-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 217796.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLCN2	NM_004366.6	c.2386C>T	p.Gln796*	stop_gained	Exon 22 of 24	ENST00000265593.9	NP_004357.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLCN2	ENST00000265593.9	c.2386C>T	p.Gln796*	stop_gained	Exon 22 of 24	1	NM_004366.6	ENSP00000265593.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.000415 Hom.: 0

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Sep 25, 2018

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Q796X variant in the CLCN2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The Q796X variant is observed in 1/15302 (0.0065%) alleles from individuals of African background in large population cohorts (Lek et al., 2016). We interpret Q796X as a likely pathogenic variant. -

Leukoencephalopathy with mild cerebellar ataxia and white matter edema Other:1

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	48
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		10
Vest4		0.96
GERP RS		5.6
Mutation Taster		=2/198	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs376823689; hg19: chr3-184069830;