Muscular Dystrophies include a heterogeneous series of diseases that range from childhood to adult onset cases, of difficult diagnosis and treatment. This book presents the state of the art in muscular dystrophies, after the molecular revolution. In the field of patients' diagnosis, several advances have been done by recognizing new entities. New techniques such as biochemical, molecular advancements, and the use of muscle MRI are collected that allow rapid diagnosis. Also, advances in therapy and therapeutical trials are presented in Duchenne and other muscular dystrophies and some novel treatments in glycogen storage disease by enzyme replacement are proposed. Both rehabilitation techniques and other treatments deserve particular attention for the improvements observed.