Pediatric aspects of skeletal dysplasia.

[achondroplasia]

Skeletal dysplasia is a disorder of skeletal development characterized by abnormality in shape , length , a number and mineral density of the bone . Skeletal dysplasia is often associated with manifestation of other organs such as lung , brain and sensory systems . Skeletal dysplasias or dysostosis are classified with more than 400 different names . Enchondral bone formation is a coordinated event of chondrocyte proliferation , differentiation and exchange of terminally maturated chondrocyte with bone . Impaired enchondral bone formation will lead to skeletal dysplasia , especially associated with short long bones . Appropriate bone volume and mineral density are achieved by balance of bone formation and bone resorption and mineralization . The gene encoding fibroblast growth factor receptor 3 is responsible for achondroplasia , representative skeletal dysplasia with short stature . The treatment with growth hormone is approved for achondroplasia in Japan . Osteogenesis imperfecta is characterized by low bone mineral density and fragile bone . Data on the beneficial effect of bisphosphonate for osteogenesis imperfecta are accumulating . Osteopetrosis has high bone mineral density , but sometimes show bone fragility . In Japan as well as other countries , pediatrician treat larger numbers of patients with skeletal dysplasia with short stature and fragile bones compared to 20 years ago .