CLCN7

Chr 16ADAR

Cl-/H+ antiporter 7

Also known as: CLC-7, CLC7, HOD, OPTA2, OPTB4, PPP1R63

Chloride channel 7 is a slowly voltage-gated channel that exchanges chloride ions for protons, contributing to lysosomal acidification and pH maintenance. Mutations cause osteopetrosis with abnormally dense bones due to defective bone resorption, presenting as severe infantile malignant osteopetrosis in the autosomal recessive form or milder adolescent/adult-onset disease in the autosomal dominant form. Some patients also develop hypopigmentation, organomegaly, and delayed myelination with developmental delays.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismAD/ARLOEUF 0.393 OMIM phenotypes
Clinical SummaryCLCN7
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Gene-Disease Validity (ClinGen)
autosomal dominant osteopetrosis 2 · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

3 total gene-disease associations curated

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.23) despite low pLI — interpret in context.
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ClinVar Variants
22 unique Pathogenic / Likely Pathogenic· 123 VUS of 300 total submissions
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GeneReview available — CLCN7
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.39LOEUF
pLI 0.272
Z-score 4.66
OE 0.23 (0.140.39)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
2.11Z-score
OE missense 0.73 (0.670.80)
358 obs / 489.6 exp
Mild constraint

Moderately missense-constrained (top ~2.5%)

Observed / Expected Ratios
LoF OE0.23 (0.140.39)
00.351.4
Missense OE0.73 (0.670.80)
00.61.4
Synonymous OE1.26
01.21.6
LoF obs/exp: 10 / 43.0Missense obs/exp: 358 / 489.6Syn Z: -3.06
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCLCN7-related osteopetrosisLOFAR
moderateCLCN7-related hypopigmentation, organomegaly, and delayed myelination and developmentOTHERAD
DN
0.7132th %ile
GOF
0.6833th %ile
LOF
0.3260th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative, gain-of-function and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
GOFprediction above median · 1 literature citation
LOF68% of P/LP variants are LoF · LOEUF 0.39

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNDominant negative mutations of the CLCN7 gene affect about 70% of ADO2 patients.PMID:29501587
GOFPrimary fibroblasts from both probands also exhibited markedly enlarged intracellular vacuoles; this finding was recapitulated by the overexpression of human p.Tyr715Cys CLCN7 in control fibroblasts, reflecting the dominant, gain-of-function nature of the variant.PMID:31155284

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

300 submitted variants in ClinVar

Classification Summary

Pathogenic6
Likely Pathogenic16
VUS123
Likely Benign151
Benign2
Conflicting2
6
Pathogenic
16
Likely Pathogenic
123
VUS
151
Likely Benign
2
Benign
2
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
3
1
2
0
6
Likely Pathogenic
12
4
0
0
16
VUS
2
105
13
3
123
Likely Benign
0
2
82
67
151
Benign
0
0
1
1
2
Conflicting
2
Total171129871300

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

View in ClinVar →

Protein Context — Lollipop Plot

CLCN7 · 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 →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 5 results · since 2015Search PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC