At what age range does Duchenne usually present?

• A. Approximately 2–5 years
• B. Infancy (0–12 months)
• C. Adolescence (12–18 years)
• D. Adult onset after 20

Answer: (A)

Duchenne muscular dystrophy usually becomes evident in early childhood. The most common presentation is around 2 to 5 years, when children develop weaknesses in the proximal muscles and show delays in walking or motor milestones. You might see trouble running, climbing stairs, or standing up from the floor, and a Gowers’ sign as they compensate for hip and thigh weakness. Calf muscles can appear enlarged due to pseudohypertrophy. Babies are often normal at birth or only mildly hypotonic, so the characteristic signs emerge as children start to walk and become more active in the 2–5 year window.

This timing helps distinguish it from other possibilities: infancy onset is less typical for Duchenne, adolescence or young adulthood suggests Becker muscular dystrophy, and adult-onset patterns aren’t characteristic of Duchenne.