Multiple Hereditary Exostoses

The chromosomal disorder that I have chosen to write about is called Multiple Hereditary Exostoses or MHE for short. Multiple Hereditary Exostoses (MHE or EXT) is an autosomal dominant trait characterized by multiple exostoses or cartilage capped bony prominences typically arising in the metaphyseal region of long bones, although the diaphysis, spine, and ribs may also be involved (Posna, 2010). People who have MHE grow exostoses, or bony bumps, on their bones which can vary in size, location, and number depending on the individual. Although any bone can be affected, the long bones, pelvis, and shoulder blades are the most common, while the face and skull are generally unaffected. Boys and girls can both be affected. The exostoses grow near the growth centers of the bone, they can make the growth center grow poorly, or only part of it grow poorly. This makes a lot of people with MHE somewhat shorter than average or have bowed arms or legs. Often, the forearm will bow out, or the legs can become knock kneed. While children are growing, exostoses can be painful. Sometimes exostoses grow near nerves or tendons and press on them. In these cases, they often need to be removed so they will not damage the structure laying over them. The most frightening complication of MHE is also one of the most uncommon. Rarely (less than 1% of the time), the benign exostoses of MHE can become a malignant tumor called chondrosarcoma. This happens almost always after adulthood when skeletal growth has ceased. Usually, patients who develop chondrosarcoma are in their 20's to 50's (Ziegler, n.d.). This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family (NLM, 2011).

The question I would ask is...