Novel approaches to treat muscular dystrophies

Muscular dystrophies (MD) are a clinically and genetically heterogeneous group of skeletal muscle-wasting diseases. Mutations in the dystrophin gene result in dystrophin deficiency, which constitutes the pathogenic basis of Duchenne and Becker MD (DMD and BMD). Several MD are caused by mutations in other recently identified genes coding for proteins linked to the sarcolemma, the nuclear envelope or the contractile apparatus. In addition, several MD have been mapped to different chromosomal loci and for most of them, the identification of the molecular defect is underway. The immediate result is an ongoing reclassification of the MD into disorders defined not by clinical characteristics but specific genetic mutations. At present, therapy of MD is based on symptomatic treatment and supportive care. Convincing evidence for clinical efficacy is only available for corticosteroids that also suffer from frequent and severe side effects. Up to now, curative therapy is not available, although promising new molecular therapies are under investigation in animal models of MD. Current treatment strategies are discussed and a perspective for effective molecular therapy is given.