DMD and Duchenne muscular dystrophy: The dystrophin gene (DMD) (OMIM 300377), located in Xp21.2-p21.1, is a 2,2 Mb gene that encodes for the dystrophin protein (DYS), a subsarcolemmal, rod-shaped protein of 427kDa involved in the formation of the dystrophin-associated protein complex (DAPC) (Ervasti and Campbell, 1993).