Otospondylomegaepiphyseal dysplasia (OSMED) is an autosomal recessive disorder of bone growth that results in skeletal abnormalities, severe hearing loss, and distinctive facial features. The name of the condition indicates that it affects hearing (oto-) and the bones of the spine (spondylo-), and enlarges the ends of bones (megaepiphyses). The features of OSMED are similar to those of another skeletal disorder, Weissenbacher-Zweymüller syndrome. Otospondylomegaepiphyseal dysplasia is a subtype of collagenopathy, types II and XI. Pathophysiology
Mutations in the COL11A2 gene cause otospondylomegaepiphyseal dysplasia. The protein made by the COL11A2 gene is involved in the production of type XI collagen. This type of collagen is important for the normal development of bone and other connective tissues. Mutations in the COL11A2 gene lead to a loss of function of this type of collagen, resulting in the signs and symptoms of OSMED. OSMED is inherited in an autosomal recessive pattern, which means the defective gene is located on an autosome, and two copies of the defective gene - one from each parent - must be inherited for a person to be affected by the disorder. The parents of a child with an autosomal recessive disorder are usually not affected but are carriers of one copy of the altered gene. A recessive pattern of inheritance makes OSMED unique among the type II and type XI collagenopathies. Diagnosis
The distinctive characteristics of OSMED include severe bone and joint problems and very severe hearing loss. This disorder affects the epiphyses, the parts of the bone where growth occurs.
External links

This article incorporates public domain text from The U.S. National Library of Medicine