The muscular dystrophies. Clinical update on two major types.

The muscular dystrophies are inherited diseases involving skeletal muscle and, to a variable extent, many other organs of the body. Each presents a distinctive clinical syndrome, and each presumably reflects a distinctive inborn error of metabolism. The precise metabolic defect is not known for any of these disorders. However, recent studies suggest that abnormalities in cellular membranes may help explain clinical deficits in two of the most important disorders, Duchenne's muscular dystrophy and myotonic muscular dystrophy.