Osteopetrosis, recessive 4-dominant 2 / Hypopigmentation, organomegaly
Definition
The CLCN7 gene (16p13.3) encodes the chloride channel CLC-7, which plays a role in the acidification process in osteoclasts. Heterozygous gain-of-function variants cause autosomal dominant osteopetrosis type 2 (ADO2), while biallelic variants cause the more severe autosomal recessive osteopetrosis type 4; some heterozygous variants may also lead to a hypopigmentation-organomegaly phenotype without skeletal involvement.
Gene/region examined
CLCN7 - Exon 1, CLCN7 - Exon 2, CLCN7 - Exon 3, CLCN7 - Exon 4, CLCN7 - Exon 5, CLCN7 - Exon 6, CLCN7 - Exon 7, CLCN7 - Exon 8, CLCN7 - Exon 9, CLCN7 - Exon 10, CLCN7 - Exon 11, CLCN7 - Exon 12, CLCN7 - Exon 13, CLCN7 - Exon 14, CLCN7 - Exon 15, CLCN7 - Exon 16, CLCN7 - Exon 17, CLCN7 - Exon 18, CLCN7 - Exon 19, CLCN7 - Exon 20, CLCN7 - Exon 21
Method
Sequence analysis
Accepted sample types
EDTA blood, AF, CVS
Inheritance
Hereditary; the osteopetrosis form may be autosomal dominant (ADO2) or recessive (OPTB4).