Chondrodysplasia punctata (CDP) is a congenital disorder characterized by a skeletal abnormality, characterized by punctate calcification of the cartilage of the epiphyses, larynx and trachea. Different forms of CDP exist, the most common of which is inherited as an autosomal recessive trait (Rhizomelic CDP). CDP may also be inherited in a recessive and dominant X-linked fashion. The X-linked recessive CDP (CDPX1) characterized by facial anomalies with severe nasal hypoplasia, short stature, and distal phalangeal hypoplasia. Mutations in ARSE which encodes arylsulfatase E, showing a high sequence homology to steroid sulfatase. In X-linked dominant CDP (CDPX2), aberrant punctate calcification in cartilage is most prominent around the vertebral column, pelvis, and long bones. Additionally, CDPX2 patients may have asymmetric rhizomesomelia, sectorial cataracts, patchy alopecia, ichthyosis, and atrophoderma. It has been found that defects in D8-D7 sterol isomerase (EBP) cause CDPX2 and suggest a role for sterols in bone development.
