DMD stands for Duchenne Muscular Dystrophy, which is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact. DMD is one of four conditions known as dystrophinopathies, and it is the most severe form of muscular dystrophy. The other three diseases that belong to this group are Becker Muscular dystrophy (BMD, a mild form of DMD); an intermediate clinical presentation between DMD and BMD; and DMD-associated dilated cardiomyopathy (heart-disease) with little or no clinical skeletal, or voluntary, muscle disease. DMD carriers are females who have a normal dystrophin gene on one X chromosome and an abnormal dystrophin gene on the other X chromosome. Most carriers of DMD do not themselves have signs and symptoms of the disease, but a minority do. Symptoms of DMD can range from mild skeletal muscle weakness or cardiac involvement to severe weakness. There is no known cure for DMD, and available treatment options are palliative.