a wasting disease
Muscular dystrophy is a term encompassing a variety of muscle wasting diseases. The most common type, Duchenne Muscular Dystrophy DMD , affects cardiac and skeletal muscle, as well as some mental functions. DMD is caused by a defective gene for dystrophin, a protein prevalent in skeletal and cardiac muscles. DMD is an X-linked recessive disorder occurring in 1 in 3,500 male newborns. Because DMD is X-linked, no females are affected. Most affected individuals die before their 20th birthday. Daughters of female carriers of the mutant allele have a 50% chance of also being carriers.