Duchenne muscular dystrophy is a genetic disease caused by pathogenic variants in the gene encoding dystrophin, a protein essential for muscle function, leading to progressive muscle weakness and loss of mobility. Several gene replacement therapies that use viral vectors to deliver shortened versions of the dystrophin gene are being tested in clinical trials. We reviewed these studies for safety and efficacy and found modest improvements in motor function, with more consistent benefits in younger children. Most patients experienced mild, transient side effects, although serious complications, including liver injury and rare fatal events, were reported. These findings support the potential of these gene therapies while highlighting the need for careful patient selection, safety monitoring, and longer-term studies. (https://jmg.bmj.com/content/early/2026/09/15/jmg-2026-111649)