Which statement is true about DMD onset and progression?

• A. Onset around age 3-4 and rapid decline by adolescence
• B. Onset in infancy with no progression
• C. Onset around age 10-12 with rapid decline
• D. Onset in late adulthood with complete recovery

Answer: (A)

DMD typically begins in early childhood and progresses rapidly, because the body lacks dystrophin to protect muscle fibers. Signs often show up around ages 3 to 4, with a pattern of proximal muscle weakness that worsens quickly. Children may develop a Gowers’ sign when getting up from the floor and later show calf pseudohypertrophy as muscle is replaced by fat and connective tissue. This rapid progression leads to loss of independent ambulation by adolescence and raises the risk of cardiopulmonary complications as teens and young adults.

That’s why onset around 3–4 years old with rapid decline by adolescence is the best description. Infancy with no progression isn’t accurate because DMD shows ongoing deterioration. Onset in the 10–12 age range with rapid decline resembles Becker muscular dystrophy more than DMD, which is typically more severe and earlier. Onset in late adulthood with complete recovery isn’t compatible with DMD’s natural history.