What is Duchenne muscular dystrophy?

Duchenne muscular dystrophy (DMD) is a rapidly progressive form of muscular dystrophy that occurs primarily in boys. It is caused by a mutation in a gene, called the DMD gene that can be inherited in families in an X-linked recessive fashion, but it often occurs in people from families without a known family history of the condition. Individuals who have DMD have progressive loss of muscle function and weakness, which begins in the lower limbs. The DMD gene is the second largest gene to date, which encodes the muscle protein, dystrophin. Boys with Duchenne muscular dystrophy do not make the dystrophin protein in their muscles.