A 28-year-old bank employee undergoes investigation for infertility that revealed oligospermia. On further inquiry, it is found that he has suffered from repeated bouts of coughing since childhood and episodes of recurrent pancreatitis. Clubbing of the fingers is evident. Which test is most likely to reveal the cause of his chronic lung disease?
High-Yield Explanation
Cystic fibrosis is the most common cause of chronic obstructive lung disease (COLD) in children and adolescents. It is an autosomal-recessive disease that affects widespread exocrine glands. COLD is evident in all patients who survive childhood.