DMD and Duchenne and Becker muscular dystrophy: Absence of dystrophin or deletion of base pairs in the dystrophin gene is a cause of Duchenne and Becker muscular dystrophy, which are allelic X-linked disorders with a progressive muscle weakness, a static cognitive impairment, autism and problems of behavior and attention (Young et al., 2008; de Brouwer et al., 2014).