Question
A patient with multiple osteochondromas asks how to prevent their daughter from suffering from the same disease.
Answer
Multiple hereditary osteochondromas have three characteristics: 1) genetic; 2) bone shortening or deformity; 3) a high incidence of malignant transformation into peripheral chondrosarcoma. Compared to solitary osteochondromas, the incidence rate is about 1:10. Due to the multifocal nature, symptoms usually appear before the age of 10. This condition is significantly more common in males, with a male-to-female ratio of 2:1. About two-thirds of cases are hereditary. If one parent has the disease, their offspring have a 50% chance of inheriting it. It is more common in male offspring, but even normal females in the same family may pass on the disease to their descendants. Multiple hereditary osteochondromas are commonly found at the metaphysis, especially around the knee, shoulder, hip, wrist, and ankle joints. They can also be observed on the spine and ribs, but are less common on the carpal and tarsal bones. In severe cases, symmetrical multifocal osteochondromas can be seen, and a diagnosis can be made solely based on physical examination. Symptoms include limb shortening and deformities, such as genu varum or valgum of the knee, ankle, elbow, or wrist. In extreme cases, family members may exhibit symptoms similar to chondrodysplasia, but in reality, chondrogenic growth function is normal. When body growth ends, osteochondromas stop growing; however, in some adult cases, significant growth of osteochondromas may be a sign of sarcomatous transformation. Sarcoma