Rhizomelic chondrodysplasia punctata is a rare, multisystem, developmental disorder characterized by the presence of stippled foci of calcification in hyaline cartilage, coronal vertebral clefting, dwarfing, joint contractures, congenital cataract, ichthyosis, and severe intellectual disability. The cataracts are present in about 72% of cases, and skin changes in about 27%. The coronal cleft of the vertebral bodies is demonstrable radiologically and appears to represent embryonic arrest with cartilage occupying the cleft between the anterior and posterior parts of the vertebral bodies. Biochemically, RCDP patients have subnormal levels of red cell plasmalogens and progressive accumulation of phytanic acid, which is normal at birth, but increases to levels more than 10 times by age of 1 year.
Most patients with rhizomelic chondrodysplasia punctata type 1 have mutations in the PEX7 gene, which encodes peroxin 7, the cytosolic PTS2-receptor protein involved in peroxisomal import of protein.
In a 5-year prospective study for newborns at Al Ain Medical District, Al-Gazali et al. (2003) defined the pattern and birth prevalence of the different types of osteochondrodysplasias in the United Arab Emirates. Among the 38,048 births during the study period, 36 (9.46/10,000 births) had some type of skeletal dysplasia of which three had autosomal recessive rhizomelic and non-rhizomelic chondrodysplasia punctata. In two of these cases, the parents were consanguineous. Al-Gazali et al. (2003) calculated the birth rate of this type of osteochondrodysplasia in the United Arab Emirates to be 0.78/10,000 births. This is higher than that reported for other world populations.