A 19-year-old man has recurrent sinopulmonary infections since childhood. Examination shows situs inversus and he gives a history of infertility. Chest imaging reveals bilateral basal bronchiectasis. The underlying defect responsible for his bronchiectasis is:

• A Defective CFTR chloride channel function
• B Absent dynein arms in ciliary microtubules ✓
• C Alpha-1 antitrypsin deficiency
• D Defective NBT reduction by neutrophils

Explanation

Kartagener syndrome is primary ciliary dyskinesia with situs inversus, bronchiectasis, sinusitis, and male infertility. The defect lies in ciliary ultrastructure, classically absent or defective dynein arms of the 9 plus 2 axoneme, causing immotile cilia and impaired mucociliary clearance. The CFTR defect defines cystic fibrosis without situs inversus, alpha-1 antitrypsin deficiency causes panacinar emphysema, and defective NBT reduction describes chronic granulomatous disease.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.