Cystic fibrosis (CF) is characterized by which combination?

Cystic fibrosis (CF) is characterized by which combination?

• A. Elevated sweat chloride levels, autosomal recessive inheritance, and pancreatic insufficiency
• B. Elevated sweat chloride levels only
• C. Autosomal dominant inheritance
• D. Normal pancreatic function

Answer: (A)

Cystic fibrosis arises from defective CFTR chloride channels, which disrupt chloride and water transport in epithelia. This leads to thick, sticky secretions in organs like the pancreas and sweat glands. The sweat glands show elevated chloride levels because chloride isn’t reabsorbed properly in the sweat ducts, making the sweat chloride test a diagnostic clue. The pancreas is typically affected, resulting in pancreatic insufficiency and fat malabsorption. The condition is inherited in an autosomal recessive pattern, meaning two mutant alleles are needed, one from each parent. So the combination that best describes CF is elevated sweat chloride levels, autosomal recessive inheritance, and pancreatic insufficiency. The option with only elevated sweat chloride is incomplete, the autosomal dominant pattern contradicts the known inheritance, and normal pancreatic function does not fit the disease.

Cystic fibrosis arises from defective CFTR chloride channels, which disrupt chloride and water transport in epithelia. This leads to thick, sticky secretions in organs like the pancreas and sweat glands. The sweat glands show elevated chloride levels because chloride isn’t reabsorbed properly in the sweat ducts, making the sweat chloride test a diagnostic clue. The pancreas is typically affected, resulting in pancreatic insufficiency and fat malabsorption. The condition is inherited in an autosomal recessive pattern, meaning two mutant alleles are needed, one from each parent.

So the combination that best describes CF is elevated sweat chloride levels, autosomal recessive inheritance, and pancreatic insufficiency. The option with only elevated sweat chloride is incomplete, the autosomal dominant pattern contradicts the known inheritance, and normal pancreatic function does not fit the disease.