QCM : Cystic Fibrosis: Pathophysiology and Management — 9 questions

Explication

The CFTR protein functions as a chloride channel that regulates ion flux across epithelial cell membranes, which is fundamental to maintaining proper hydration of mucus. Its malfunction leads to thick, sticky mucus characteristic of cystic fibrosis. The other options are incorrect: CFTR does not encode a receptor, is not primarily structural, and does not synthesize mucus.

Explication

CFTR is a gated anion channel that regulates ion flux across epithelial cell membranes, primarily controlling chloride movement. Its proper function ensures adequate hydration of mucus on epithelial surfaces. When defective, decreased chloride and water secretion lead to thick mucus characteristic of CF.

Explication

The source states that the G551D mutation is a target for CFTR potentiator therapy, such as ivacaftor. Francis S. Collins is well known for his work in genetics and was instrumental in the development and proposal of targeted therapies for specific CFTR mutations, including G551D. The other options are notable figures but are not associated with this specific discovery or proposal in CF research.

Explication

CFTR mutations impair chloride channel function, leading to decreased chloride and water transport across epithelial cells. This causes thick, sticky mucus accumulation, which obstructs airways and ducts, leading to tissue damage and the clinical features of cystic fibrosis.

Explication

Postural drainage combined with percussion and vibration is a standard physiotherapy technique used in CF to help clear mucus from the lungs, as it facilitates mucus mobilization and expectoration. The source explicitly states that physiotherapy helps clear mucus to maintain lung function, which involves techniques like postural drainage.

Explication

The source states that Pseudomonas aeruginosa colonization is common in CF lung disease and often requires targeted antibiotic therapy, making it the most associated bacteria with chronic lung infection in CF.

Explication

The source states that 'The median age of diagnosis is around 23 days', indicating that diagnosis most commonly occurs at this age, largely due to newborn screening programs.

Explication

Recognizing CFRD is crucial because it results from pancreatic damage leading to insulin deficiency. Early detection allows for timely insulin therapy, which is essential for managing blood glucose levels and preventing further complications related to diabetes in CF patients.

Explication

Liver issues involve structural organ damage such as cirrhosis and portal hypertension, which are consequences of biliary disease. In contrast, reproductive issues in CF, such as absent vas deferens or thick cervical mucus, are due to congenital developmental abnormalities or functional impairments. The source explicitly describes these mechanisms, making option 0 correct.