CLCN2

Chr 3ADAR

chloride voltage-gated channel 2

Also known as: CIC-2, CLC2, ECA2, ECA3, EGI11, EGI3, EGMA, EJM6

This gene encodes a voltage-gated chloride channel that maintains chloride ion homeostasis and regulates neuronal excitability, aldosterone production in adrenal glands, and chloride flux in glial cells. Mutations cause leukoencephalopathy with ataxia, familial hyperaldosteronism type II, and susceptibility to various epilepsy syndromes including juvenile absence epilepsy and juvenile myoclonic epilepsy. Inheritance follows both autosomal dominant and autosomal recessive patterns depending on the specific condition.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismAD/ARLOEUF 0.775 OMIM phenotypes
Clinical SummaryCLCN2
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Gene-Disease Validity (ClinGen)
epilepsy · ADRefuted

Refuted — evidence has disproved this relationship

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
22 unique Pathogenic / Likely Pathogenic· 178 VUS of 300 total submissions
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GeneReview available — CLCN2
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.77LOEUF
pLI 0.000
Z-score 2.83
OE 0.55 (0.410.77)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.65Z-score
OE missense 0.92 (0.850.99)
494 obs / 536.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.55 (0.410.77)
00.351.4
Missense OE0.92 (0.850.99)
00.61.4
Synonymous OE1.09
01.21.6
LoF obs/exp: 26 / 46.9Missense obs/exp: 494 / 536.6Syn Z: -0.97
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCLCN2-related leukoencephalopathy with ataxiaLOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.80top 10%
GOF
0.78top 25%
LOF
0.2386th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Literature Evidence

GOFA gain-of-function mutation in the CLCN2 chloride channel gene causes primary aldosteronism.PMID:29403012

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

300 submitted variants in ClinVar

Classification Summary

Pathogenic14
Likely Pathogenic8
VUS178
Likely Benign70
Benign2
Conflicting2
14
Pathogenic
8
Likely Pathogenic
178
VUS
70
Likely Benign
2
Benign
2
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
7
0
7
0
14
Likely Pathogenic
8
0
0
0
8
VUS
3
154
14
7
178
Likely Benign
0
3
32
35
70
Benign
0
0
2
0
2
Conflicting
2
Total181575542274

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

CLCN2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →
Full-Text Mentions
NLP-detected gene mentions in article bodies · via PubTator3
PubTator3
Top 5 full-text resultsSearch PubTator3 ↗
Key Publications
Landmark & review papers · by relevance
PubMed
Top 5 results · since 2015Search PubMed ↗