Hereditary multiple exostoses is an autosomal dominant condition producing a disorder of bone growth plates. This results in multiple cartilage osteomas developing at the ends of long bones.
Multiple bone swellings first appear in infancy and increase in number and size during growth. The lesions may result in pain, deformity and growth impairment.
The autosomal dominant change in 30% is due to new mutations. The overall incidence is 1 in 2000.
There is a small proportion of patients - perhaps 2% - in which there seems to be a predisposition to malignant sarcoma transformation in later life.
Last reviewed 01/2018