The congenital myopathies and congenital muscular dystrophies are a group of relatively infrequent neuromuscular disorders. Ultimate understanding of these disorders, however, will undoubtedly shed considerable light on skeletal muscle development and function. Three classical congenital myopathies are central core disease, nemaline myopathy, and centronuclear myopathy. The congenital muscular dystrophies are often distinguished by whether or not they are associated with clinically evident cerebral involvement.