Duchenne muscular distrophy
Duchenne muscular distrophya SEX LINKED human condition, in which a recessive gene on the short arm of the X-chromosome causes muscle wasting when present in a double dose in females or a single dose in HEMIZYGOUS males. Muscular deterioration begins between the ages of three and five, affecting mainly boys; by the teens affected individuals are wheelchair bound and death usually occurs in the early twenties due to cardiac and respiratory muscle failure.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005