At what age range does Duchenne muscular dystrophy typically onset?

• A. 1-5 years
• B. 2-10 years
• C. 10-15 years
• D. 15-20 years

Answer: (B)

Duchenne muscular dystrophy (DMD) typically manifests between the ages of 2 and 10 years. This disorder is characterized by progressive muscle degeneration and weakness, predominantly affecting boys due to its X-linked recessive inheritance pattern. The symptoms usually begin with difficulty in walking, muscle weakness in the hips, pelvic area, thighs, and shoulders, often resulting in delayed milestones such as walking or running.

Choosing the age range of 2-10 years aligns perfectly with the common clinical presentation and the developmental timeline where parents may first notice symptoms related to mobility and muscle strength. The earlier onset within this range is typically marked by parents observing difficulties in movements that would be expected at those ages, making it a critical period for the diagnosis of DMD.