Muscular dystrophy is a general name for a group of genetic diseases that can affect the muscles anywhere in the body (Muscular, 2000). Types of muscular dystrophy (MD) include Becker's MD, congenital MD, myotonic MD, Duchenne MD, Erb's (Limb-girdle) MD, and ocular MD. The symptoms of MD will depend on the type of MD present, but all will include weakness and loss of muscle mass. There is no cure as yet for MD, nor is there any treatment, but exercise is important in maintaining what muscles are still functioning. Loss of swallowing ability may lead to the insertion of a feeding tube into the stomach for liquid feeding. Surgery may be necessary to reduce contractures.
Duchenne and Becker's MD are most common in children, and boys usually get the disease between the ages of two and 15 years of age (Duchenne, 2000). With Becker's MD it is possible to live a normal life, but with Duchenne MD, the life-span will be shortened. Scientists believe that the dystrophin gene on the X-chromosome is damaged in MD. The gene codes for the dystrophin protein, which is necessary for the structural support of muscles (Gregorevic et al., 2004). In MD, lack of dystrophin production leads to weakening of muscles, and in time the body stops making muscle cells and replaces them with fat and connective tissue.
Myotonic MD is the most common form of MD in adults and affects the eyes, heart, hormonal system, and blood, as well as causing muscular dystrophy and involuntary muscle stiffness (myotonia) (Gene, 2001, 3). The genetic change underlying one form of myotonic MD (DMI) has been found on chromosome 19, but scientists have differed in their opinions on how it causes the disease. A pair of American scientists from Minnesota has identified a second form of myotonic dystrophy (DM2) and they have located the genetic defect on chromosome 3. They have now collaborated with other American scientists as well as a group in Germany to find t...