DMD and Becker muscular dystrophy: 2012), and de novo mutations continue to arise in all populations worldwide. Boys with DMD exhibit symptoms around 3–5 years of age, with abnormal gait, weakened proximal muscles and calf muscle pseudohypertrophy. The development of scoliosis coincides with wheelchair support by the age of 12 years (Emery, 1993) and patients usually die from respiratory and cardiac complications by 30 years of age (Bach et al. 1987). In Becker muscular dystrophy (BMD), partial deletion of dystrophin compromises its function, but patients can remain ambulant even at 60 years old (Emery, 1990).