DMD and Duchenne muscular dystrophy: The reading frame rule explains the clinical differences between DMD/ BMD at the molecular level with the deletions that cause shifts in the reading frame of the dystrophin mRNA (out-of-frame) that lead to no or very low production of functional dystrophin resulting in more severe DMD phenotype whereas the milder BMD phenotype occurs if the reading frame is preserved (in-frame) and semi functional proteins are produced (7).