Novel Therapeutic Frontiers in Duchenne Muscular Dystrophy: Gene Therapy, Exon Skipping, and Stem Cell Approaches

Duchenne Muscular Dystrophy (DMD) is a chronic X-linked recessive neuromuscular disorder with a prevalence of 1 in 3,500 to 5,000 live male births worldwide. Alterations in the dystrophin gene, one of the biggest known human genes with 2.5 million base pairs and 79 exons, located at Xp21.1, are responsible for the disease. The dystrophin protein, an essential structural component that links the muscle cell cytoskeleton actin to the extracellular matrix through the dystrophin-associated protein complex, is either lacking or dysfunctional due to these mutations. Dystrophin deficiency compromises muscle membrane stability, leading to gradual deterioration of muscle fibers, fibrosis, and replacement by adipose tissue. Numerous disrupted physiological pathways, such as calcium dysregulation, faulty nitric oxide signaling, altered PI3K-Akt-mTOR growth signaling, chronic inflammatory responses, and oxidative stress, are implicated in the pathophysiology of DMD. Affected males clinically demonstrate early childhood muscular weakness; characteristic signs such as Gower's maneuver and calf hypertrophy; increasing ambulation loss by adolescence; and potentially lethal cardiorespiratory problems that generally manifest in the third decade of life. Corticosteroids remain the primary therapeutic modality, significantly improving ambulation and quality of life; nevertheless, extended use entails severe adverse effects. Recent treatment advancements provide renewed optimism via diverse innovative strategies, namely CRISPR-Cas9 gene editing, antisense oligonucleotide-mediated exon skipping (eteplirsen, golodirsen, viltolarsen, and casimersen), microdystrophin gene therapy using Adeno-Associated Viral (AAV) vectors, stop codon read-through therapy, and stem cell-based treatments. But difficulties with cost, immunogenicity, efficacy, and mutant specificity persist. Through multidisciplinary treatment and continuous scientific progress, individualized precision medicine that integrates therapies targeting secondary pathogenic pathways with dystrophin-restoration techniques can finally convert this devastating illness into a tolerable chronic ailment.