The near-total absence of full-length dystrophin production in DMD patients results in progressive muscle degeneration that manifests primarily as muscle weakness impairing walking, other motor functions, breathing, and cardiac function,4 with the most common cause of death being cardiorespiratory failure.5 Although the pace of symptom progression is heterogenous in DMD patients, muscle weakness typically begins between ages 3 and 5 years, with loss of ambulation usually occurring in the early teenage years and loss of ability to self-feed by the late teenage years. This evidence concerns the gene DMD and Duchenne muscular dystrophy.