Which of the following is a progressive genetic disease characterized by persistent lung infections?

• A. Muscular dystrophy
• B. Multiple sclerosis
• C. Cerebral palsy
• D. Cystic fibrosis

Answer: (D)

This item focuses on recognizing a genetic condition that is progressive and causes ongoing lung infections. Cystic fibrosis results from mutations in the CFTR gene, leading to thick, sticky mucus in the lungs and other organs. That mucus traps bacteria and promotes chronic lung infections that tend to worsen over time, which reflects the progressive nature of the disease. The other conditions don’t share this hallmark: muscular dystrophy is primarily a muscle-wasting condition and doesn’t define persistent lung infections; multiple sclerosis is an autoimmune process affecting the central nervous system; cerebral palsy is a motor disability from early brain injury. Therefore, cystic fibrosis best fits the description.