Duchenne muscular dystrophy (DMD) affects 1 in every 3,500 newborn boys and very rarely it also affects girls (approximately 1 in 50 million girls). DMD is not specific to any one group, crossing all cultures and races.
DMD is a genetic disorder. The gene defect prevents the muscle cells from making an important protein called dystrophin. Dystrophin provides stability to the walls of muscle cells. Without this protein, muscle cells break down and die. More boys have Duchenne because the gene that causes it, dystrophin, is located on the X chromosome. This is one of the chromosomes that determines our gender – females have two X chromosomes and males have one X and one Y.
Since females have two X chromosomes, usually the healthy X chromosome can compensate for the faulty one and most of the time females don’t show any symptoms or symptoms are very mild. However, there are exceptions and Duchenne Foundation are in contact with several Australian families with girls with Duchenne.