Hereditary Multiple Exostoses

Hereditary Multiple Exostoses (HME), also known as Multiple Osteochondromas, is a genetic disorder characterized by the development of multiple exostoses, which are abnormal bony growths that develop on the bones. These growths are typically benign but can cause a range of symptoms depending on their size and location. HME is a condition that affects individuals from childhood and can continue to develop new exostoses until the late teens or early adulthood.

Causes

Hereditary Multiple Exostoses is caused by mutations in the EXT1 or EXT2 genes. These genes are involved in the development and growth of bones. Mutations in these genes lead to abnormal cell growth, resulting in the formation of exostoses. HME is inherited in an autosomal dominant manner, meaning that only one copy of the mutated gene, inherited from either parent, is sufficient to cause the disorder.

Symptoms

The symptoms of Hereditary Multiple Exostoses can vary significantly among individuals. Common symptoms include:

• Painful bony growths
• Deformities in the affected bones
• Limited range of motion in the joints near the exostoses
• Short stature, in some cases
• Pressure on nerves, blood vessels, or surrounding tissues, leading to additional complications

Diagnosis

Diagnosis of Hereditary Multiple Exostoses typically involves a combination of physical examination, family history, and imaging tests such as X-rays or MRIs. These imaging tests help in identifying the presence and extent of the exostoses. Genetic testing can also be conducted to confirm the diagnosis by identifying mutations in the EXT1 or EXT2 genes.

Treatment

There is no cure for Hereditary Multiple Exostoses, but treatment focuses on managing symptoms and preventing complications. Treatment options may include:

• Pain management with medications
• Physical therapy to improve range of motion and strength
• Surgical removal of exostoses that cause significant symptoms or complications
• Regular monitoring to detect any malignant transformation of the exostoses into chondrosarcoma, a type of bone cancer, although this is rare

Prognosis

The prognosis for individuals with Hereditary Multiple Exostoses varies. Many people with the condition live normal, active lives with appropriate management of symptoms. However, the risk of complications, including the potential for malignant transformation of exostoses, necessitates regular medical follow-up.

See Also

• Genetic Disorders
• Bone Tumor
• Chondrosarcoma