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)
* Progressive deafness * Ear deformities * Thin hair * Thick leathery skin * Soft tissue calcification
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.
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. People with the condition are often shorter than average because the bones in their arms and legs are unusually short. Other skeletal signs include enlarged joints, short hands and fingers, and flat bones of the spine (vertebrae). People with the disorder often experience back and joint pain, limited joint movement, and arthritis that begins early in life. Severe high-tone hearing loss is common. Typical facial features include protruding eyes; a sunken nasal bridge; an upturned nose with a large, rounded tip; and a small lower jaw. Some affected infants are born with an opening in the roof of the mouth, which is called a cleft palate.
The 'prognosis' of Otospondylomegaepiphyseal dysplasia usually refers to the likely outcome of Otospondylomegaepiphyseal dysplasia. The prognosis of Otospondylomegaepiphyseal dysplasia may include the duration of Otospondylomegaepiphyseal dysplasia, chances of complications of Otospondylomegaepiphyseal dysplasia, probable outcomes, prospects for recovery, recovery period for Otospondylomegaepiphyseal dysplasia, survival rates, death rates, and other outcome possibilities in the overall prognosis of Otospondylomegaepiphyseal dysplasia. Naturally, such forecast issues are by their nature unpredictable.