PE27.12 | Duchenne Muscular Dystrophy — Summary & Reflection

KEY TAKEAWAYS

Duchenne muscular dystrophy is an X-linked recessive progressive muscular dystrophy caused by out-of-frame mutations in the dystrophin gene (Xp21), resulting in absent dystrophin protein and progressive muscle fibre necrosis and fibrofatty replacement. It presents between ages 3 and 5 years with proximal lower limb weakness, Gower's sign, calf pseudohypertrophy (fibrofatty infiltration, NOT true hypertrophy), and markedly elevated CK (10–100x ULN). Becker MD arises from in-frame mutations producing truncated but partially functional dystrophin — milder and later-onset. Diagnosis is confirmed by MLPA (deletions/duplications) or NGS (point mutations); muscle biopsy shows absent dystrophin immunostaining. Management includes: corticosteroids (prednisolone 0.75 mg/kg/day — weight-based, started in ambulatory phase to delay ambulation loss by 2–5 years), cardiac monitoring with ACE inhibitor prophylaxis from age ~10 years, respiratory support (NIV when FVC <50%), orthopaedic management (AFO, scoliosis surveillance), and mutation-specific therapies (exon-skipping ASOs for amenable mutations, ataluren for nonsense mutations, mini-dystrophin gene therapy). Genetic counselling, carrier testing in female relatives, and prenatal diagnosis are essential components of family management.

REFLECT

Consider the burden of DMD from a family's perspective: a diagnosis delivered at age 4–5 years means parents must simultaneously absorb the prognosis (loss of ambulation in early teens, cardiac and respiratory complications in adulthood, potentially shortened lifespan), begin advocating for therapy access, and sustain a positive home environment for the child's remaining ambulatory years. In India, gene-targeted therapies remain largely inaccessible due to cost. Reflect on: how would you communicate the diagnosis sensitively but honestly to a family with limited health literacy? How would you triage the management priorities — corticosteroids, cardiac monitoring, physiotherapy — in a district hospital setting without specialist access? What is the role of a paediatrician in connecting families to patient advocacy resources and ensuring genetic counselling for extended family members? What does equity in rare disease care look like in the Indian context?