What key characteristic defines Duchenne muscular dystrophy?

Duchenne muscular dystrophy (DMD) is primarily characterized by progressive weakness. This condition is caused by a genetic mutation that affects the dystrophin protein, which is crucial for muscle function. As a result, individuals with DMD experience a gradual degeneration of muscle fibers, leading to muscle weakness and loss of function.

This progressive nature of the weakness means that symptoms typically worsen over time, starting in early childhood and leading to significant disability as the individual ages. While other options mention aspects that may relate to muscular dystrophies or other conditions, they do not define Duchenne muscular dystrophy specifically. For instance, DMD usually manifests in young boys rather than adults, primarily affects males rather than females, and is not characterized by acute pain, which is more associated with inflammatory or traumatic muscle injuries. Thus, progressive weakness stands out as the fundamental characteristic of DMD.