Multiple Osteochondromas (MO) is the preferred term used by the World Health Organization (WHO)
MHE/MO/HME is a genetic bone disorder in which benign cartilage-capped bone tumors grow outward from the metaphyses of long bones, growth plates or from the surface of flat bones throughout the body. The severity of this disease varies. Some patients may have as few as two tumors, but most patients develop many more and the numbers of tumors can run into the hundreds.
These Exostoses/Osteochondromas can cause numerous problems, including: compression of peripheral nerves or blood vessels; irritation of tendons and muscles resulting in pain and loss of motion; skeletal deformity; short stature; limb length discrepancy; chronic pain and fatigue; mobility issues; early onset arthritis; and an increased risk of developing malignant tumor transformation (chondro-sarcoma) reported risk of 2%-5% over life time.
It is not uncommon for MHE/MO/HME patients to undergo numerous surgical procedures throughout their lives to remove painful or deforming Exostoses/Osteochondromas and or to correct limb length discrepancies and improve range of motion. Surgery, physical therapy and pain management are currently the only options available to MHE/MO/HME patients, but their success varies from patient to patient and many struggle with chronic pain, fatigue and mobility problems throughout their lives.
MHE/MO/HME is a genetic autosomal dominant hereditary disorder. This means that a patient with MHE/MO/MHE has a 50% chance of transmitting this disorder to his/her children. There are two known genes that cause this disease EXT1 located on chromosome 8q23-q24 and EXT2 located on chromosome 11p11-p12. Approximately 60 to 70 % are located EXT1 gene and 20 to 30% are located EXT2 mutation. In 10 to 20% of the patients, no mutation is found. 10% -20% of individuals with MHE/MO/HME have the condition as a result of a spontaneous mutation, thus they are the first person in their family to be affected.
MHE Research Foundation - www.MHEResearchFoundation.org
