Question: What is (are) Familial osteochondritis dissecans ?
Answer: Osteochondritis dissecans is a joint condition that occurs when a piece of cartilage and the thin layer of bone beneath it, separates from the end of the bone. If the piece of cartilage and bone remain close to where they detached, they may not cause any symptoms. However, affected people may experience pain, weakness and/or decreased range of motion in the affected joint if the cartilage and bone travel into the joint space. Although osteochondritis dissecans can affect people of all ages, it is most commonly diagnosed in people between the ages of 10 and 20 years. In most cases, the exact underlying cause is unknown. Rarely, the condition can affect more than one family member (called familial osteochondritis dissecans); in these cases, osteochondritis dissecans is caused by changes (mutations) in the ACAN gene and is inherited in an autosomal dominant manner. Treatment for the condition varies depending on many factors, including the age of the affected person and the severity of the symptoms, but may include rest; casting or splinting; surgery and/or physical therapy.
Source: GARD