What best defines muscular dystrophy?

• A. A genetic condition causing progressive muscle weakness due to muscle fiber degeneration.
• B. A vitamin deficiency causing muscle cramps.
• C. An autoimmune disease causing skin rashes.
• D. A temporary infection of muscles.

Answer: (A)

Muscular dystrophy is a group of inherited disorders where genetic mutations disrupt the proteins that keep muscle fibers healthy, leading to progressive weakness and degeneration of skeletal muscles over time. This explains why the statement provided is the best definition: it captures both the genetic cause and the progressive loss of muscle function due to muscle fiber degeneration.

Other ideas don’t fit as well because a vitamin deficiency would cause symptoms like cramps but isn’t about ongoing muscle fiber degeneration; an autoimmune disease causing skin rashes points to conditions like dermatomyositis rather than a genetic muscle-weakness disorder; and a temporary infection would be short-lived, not a chronic progressive muscle degeneration.