At what age does Duchenne muscular dystrophy typically begin to show symptoms?

Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness. Symptoms of DMD typically start to become noticeable in early childhood, specifically between the ages of 3 and 5 years. This aligns with the onset of walking and physical activity, where parents may first observe delays in motor milestones, difficulty running or climbing stairs, and an unusual gait or frequent falls.

As the disease progresses, muscle weakness becomes more pronounced, beginning with the proximal muscles, which are closest to the body's center, affecting the hips, thighs, and shoulders. This early onset is crucial for timely diagnosis and management, as early intervention can help in planning supportive therapies and addressing the various challenges children with DMD might face as they grow.

In comparison, other ages listed in the choices do not reflect the typical clinical presentation of DMD, as initial symptoms are rarely seen before the age of 3 or significantly after age 5.