Changes in skeletal dysplasia nosology.

Skeletal dysplasia (SD), also called osteochondrodysplasia (OCD), is a large group of skeletal disorders (over 400 distinct entities) caused by abnormalities in bone development and growth. SDs varies according to different natural histories, prognoses, hereditary patterns to etiopathogenetic mechanisms. At birth, the incidence is low, reported at the level of each entity, but taken collectively; the incidence is estimated at 1:5000 births.