Muscular dystrophy

Muscular dystrophies are a heterogeneous group of inherited progressive disorders of muscle characterized pathologically by destruction of muscle and its replacement by fatty and fibrous tissue. The most common muscular dystrophies are Duchenne muscular dystrophy, myotonic dystrophy types 1 and 2, and facioscapulohumeral dystrophy. Muscle weakness is a major manifestation and often has an early onset, but initial symptoms may also be reported in early or even late adulthood. Genes with mutations causing muscular dystrophies typically play major roles in muscle development and maintenance of muscle function, including the reinforcement and repair of the plasma membrane. The considerable mechanical forces involved in contractility and the energy demands for metabolism and regeneration significantly affect the physiology of muscle fibers. Recent scientific advances have improved our diagnostic abilities and enabled experimental studies of gene therapy and conventional pharmacological treatments that should eventually lead to effective treatment of these hereditary disorders.