The genetic basis of the osteochondrodysplasias

The osteochondrodysplasias are a heterogeneous group of disorders character ized by abnormal growth and remodeling of cartilage and bone, affecting fro m 2 to 4.7 per 10,000 individuals. Most osteochondrodysplasias are heritabl e and many have elaborate patterns of genetic transmission. Affected indivi duals generally require management by multidisciplinary teams of specialist s. In this review, we divide the osteochondrodysplasias into groups based o n their genetic relationships, including mutations in various types of coll agen, fibroblast growth factor, cartilage oligomeric matrix protein, parath yroid hormone receptor, the diastrophic dysplasia sulfate transporter, enzy mes such as steroid sulfatases, transcription factor SOX9, and a cysteine p roteinase, cathepsin K. We describe the major osteochondrodysplasias, defin e their causes and clinical manifestations, and provide the orthopaedic sur geon with an understanding of the underlying molecular defects as well as t he anatomical aspects of these disorders.