Overview of the muscular dystrophies.

The muscular dystrophies are a clinically and genetically heterogeneous group of myopathies typically associated with progressive weakness. Weakness may be noted at birth or develop in late adult life. Some patients manifest with myalgias, rhabdomyolysis, or only raised serum creatine kinase levels without any symptoms or signs of weakness. The muscular dystrophies can be inherited in an X-linked, autosomal recessive, or autosomal dominant fashion and can result from mutations affecting structural proteins localizable to the sarcolemmal proteins, nuclear membrane, basement membrane, sarcomere, or nonstructural enzymatic proteins. This chapter provided a brief overview of the muscular dystrophies before later chapters discuss the individual subtypes in greater detail.