This gene encodes a large, rod-like cytoskeletal protein which is found at the inner surface of muscle fibers in skeletal and cardiac muscles. The encoded protein, dystrophin, is part of the dystrophin-glycoprotein complex, which bridges the inner cytoskeleton (F-actin) and the extra-cellular matrix. This protein is required for proper development and organization of myofibers as contractile units in striated muscles. Mutations in the human gene cause Duchenne and Becker Muscular Dystrophies and a form of heart disease called DMD-associated dilated cardiomyopathy. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined. [provided by RefSeq, Sep 2015]