Biology 11th Edition by Cecie Starr ,Ralph Taggart

Exercise 13

Duchenne muscular dystrophy , a genetic disorder, affects boys almost exclusively. Muscles begin to atrophy (waste away) in affected children, who typically die in their teens or early twenties (Section 12.7).
Muscle biopsies of a few women who carry an allele that is associated with the disorder identified some body regions of atrophied muscle tissue. They also showed that muscles adjacent to a region of atrophy were normal or even larger and more chemically active, as if to compensate for the weakness of the adjoining region.
Form a hypothesis about the genetic basis of Duchenne muscular dystrophy that includes an explanation of why the symptoms might appear in some body regions but not others.