At what age does Duchenne muscular dystrophy typically present?

• A. Adulthood
• B. Early childhood (usually 3–5 years)
• C. Infancy
• D. Adolescence

Answer: (B)

Duchenne muscular dystrophy typically presents in early childhood, around ages 3 to 5 years. After walking begins, signs of proximal muscle weakness become noticeable: difficulties with climbing stairs, running, and rising from the floor. A classic early clinical sign is the Gowers maneuver, where the child uses the hands to push up from the thighs to stand due to weak hip and thigh muscles. Calf muscles often become enlarged (pseudohypertrophy) from fatty replacement. Infancy is usually normal or with only subtle signs, while adolescence and later describe progression to more significant impairment, and adulthood is not typical for initial presentation. Becker muscular dystrophy, by contrast, tends to present later, in adolescence or early adulthood, and is often milder.