Which therapy is categorized as exon skipping therapy for Duchenne muscular dystrophy (DMD)?

• A. Corticosteroids (Prednisone, Deflazacort)
• B. Exon skipping therapy (Eteplirsen, others)
• C. Gene therapy (Elevidys)
• D. Physical therapy

Answer: (B)

Exon skipping therapy uses antisense molecules to hide a specific exon during RNA splicing, causing cells to skip that exon and restore the downstream reading frame of the dystrophin gene. This can convert a frameshift mutation into a translatable message, producing a shorter but functional dystrophin protein and slowing disease progression in Duchenne muscular dystrophy. A representative therapy in this category is eteplirsen, designed for patients whose mutations are amenable to skipping exon 51.

Corticosteroids help manage symptoms and slow progression by reducing inflammation, but they don’t alter splicing. Gene therapy delivers a dystrophin or mini-dystrophin gene, not an exon-skipping approach. Physical therapy supports function but is not a genetic treatment.