Asthma USMLE Step 1 Practice Question
A 19-year-old man with chronic productive cough, recurrent sinusitis, and otitis media since childhood presents with dyspnea. Vital signs: BP 118/76, HR 88, RR 22, Temp 37.2°C, SpO2 94% on room air. Physical examination reveals dextrocardia and decreased breath sounds bilaterally; no clubbing noted. Chest X-ray shows bronchiectasis. Semen analysis demonstrates immotile sperm. He takes albuterol as needed but has never used inhaled corticosteroids. Which of the following is the most likely molecular defect?
Answer choices
- ANADPH oxidase deficiency
- BAlpha 1 antitrypsin deficiency
- CElastin gene mutation
- DDefective dynein arms in ciliaCorrect answer
- ECFTR chloride channel misfolding
- FSurfactant protein B deficiency
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