As shown in previous studies, BMD phenotype is partly predicted by specific DMD mutations: deletions including in-frame exons in the proximal rod domain3, or the hinge 3 domain encoded by exons 50–514,5, have been associated to mild phenotypes, while deletions situated in the exon 45–53 mutational hotspot6, but not including exons 50–51, usually cause “typical” BMD7–9. The gene discussed is DMD; the disease is Becker muscular dystrophy.