Progressive muscle disease in a young woman with family history of Duchenne's muscular dystrophy.

A 16-year-old girl with an extensive family history of Duchenne's muscular dystrophy (DMD) had clinical and laboratory evidence of progressive muscle disease in preadolescence. Other female members of the kindred had exceptionally high creatine phosphokinase levels, and her mother was also symptomatic. Although manifesting carriers of DMD are common, they usually demonstrate a mild and static myopathy. This patient is unusual because her muscle disease was progressive and disabling.