A genetic disorder present at birth affecting both respiratory and digestive systems?

• A. PKU
• B. Sickle cell disease
• C. Cystic fibrosis
• D. Tay-Sachs

Answer: (C)

A congenital multisystem condition that involves the respiratory and digestive systems is cystic fibrosis. It’s caused by mutations in the CFTR gene present from birth, and it affects exocrine glands, producing very thick, sticky mucus. In the lungs this mucus blocks airways, leading to coughing and recurrent infections; in the digestive system it blocks pancreatic ducts, impairing enzyme release and nutrient absorption. That combination—birth-present genetic origin with both lung and digestive involvement—fits CF best.

The other options don’t typically present with both systems together from birth. PKU is a metabolic disorder affecting amino acid processing and mainly risks nervous system outcomes if untreated. Sickle cell disease is a blood disorder altering red blood cells and oxygen delivery. Tay-Sachs is a neurodegenerative condition affecting the nervous system.