DMD and Duchenne muscular dystrophy: Duchenne muscular dystrophy (DMD, OMIM #310200), an X-linked recessive disorder, characterized by progressive muscle degeneration and weakness, is caused by variations in the DMD gene (OMIM #300377), including deletions (60%–70%), duplications (10%), small rearrangements, and point mutations (Tuffery-Giraud et al., 2009).