What is muscular dystrophy?

• A. Inherited, muscle enlarge due to increased fat and connective tissue, but fibers degenerate and atrophy.
• B. Autoimmune disease
• C. Caused by vitamin deficiency
• D. Infection of muscles

Answer: (A)

Muscular dystrophy is a group of inherited disorders in which skeletal muscles progressively weaken and degenerate. A key feature is that the muscles may look enlarged due to fat and connective tissue infiltrating the muscle, while the actual muscle fibers degenerate and atrophy, causing increasing weakness over time. This combination—genetic origin, progressive muscle loss, and replacement of muscle fibers with fat and connective tissue—explains why the condition presents with apparent enlargement but functional decline. It’s not autoimmune, vitamin-deficiency–related, or due to infection. Autoimmune muscle diseases involve immune attack on muscle tissue; vitamin deficiencies affect metabolism in different ways; infections cause inflammatory changes from pathogens. The described pattern fits the inherited dystrophic process that leads to muscle degeneration with fatty and connective tissue replacement.