Duchenne muscular dystrophy typically presents in which age range?

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

Answer: (C)

Duchenne muscular dystrophy tends to show up as weakness in the proximal muscles during early childhood. The disorder is due to a mutation in the dystrophin gene and is X-linked, so affected boys typically become noticeable around the toddler to preschool years. Most children first display signs between about 2 and 5 years old—often with delayed walking, frequent falls, or difficulty running and climbing stairs. As the disease progresses, they may adopt a Gowers maneuver to stand up and develop calf pseudohypertrophy, with functional decline starting in early childhood and advancing through school age.

Infancy is usually too early for the first recognizable symptoms, and adolescence or adulthood would reflect progression after the initial presentation rather than the typical onset. Therefore, the most common age range for initial presentation is early childhood, around 3–5 years.