Metachondromatosis: a report of two cases in a family.

We have described a 10-year-old Japanese boy and his father with metachondromatosis characterized by multiple exostoses, enchondromas, and periarticular calcification or ossification and reviewed the literature on this condition. The boy developed bilateral epiphyseal changes in the hips mimicking Perthes' disease. These cases are the first Japanese individuals with this disorder. The natural history and the associated disorders of metachondromatosis are also discussed in this paper. Metachondromatosis is an inherited skeletal dysplasia characterized by multiple cartilaginous exostoses, multiple enchondromas, and periarticular calcification or ossification. The mode of inheritance of the disease is autosomal dominant. In 1971, Maroteaux first described the disorder in 6 patients of 2 kindreds. Since then, 22 cases have been reported. However, no Japanese patient with this disorder has been described to date. We herein report a Japanese boy and his father with this rare bone dysplasia. The boy developed bilateral epiphyseal lesions in the femoral heads mimicking Perthes' disease.