DMD is a rare genetic disease that is characterized by progressive muscle degeneration and weakness. As the most common muscular dystrophy, DMD is caused by the loss of anti-dystrophin, a protein that helps keep muscle cells intact. The initial symptoms usually appear between the ages of 3 and 5 and worsen over time. The disease usually occurs in people without a known family history, mainly affecting boys, but also rarely in girls. One in every 3,600 baby boys worldwide has DMD.
DMD patients progressively lose their ability to move independently and usually require a wheelchair early in their teens. As the disease progresses, patients may develop life-threatening heart and respiratory diseases, usually dying in their 20s or 30s. However, the severity of the disease and life expectancy may vary from person to person.