USMLE Answer 30
30. The correct answer is C. The husband is suffering from Kartagener syndrome, an autosomal recessive disorder characterized by infertility, situs inversus, chronic sinusitis, and bronchiectasis. The underlying cause of these varied manifestations is a defect in the dynein arms, which are spokes of microtubule doublets of cilia in the airways and the reproductive tract. Since sperm motility is dependent on the functioning of cilia, infertility frequently accompanies this disorder. Situs inversus occurs because ciliary function is necessary for cell migration during embryonic development.
Azoospermia (choice A) is not a feature of Kartagener syndrome, as sperm production or survival is not affected in this disorder.
Germinal cell aplasia (choice B), also known as Sertoli-only syndrome, is characterized by oligospermia or azoospermia.
Isolated gonadotropin deficiency (choice D) is characterized by delayed or incomplete pubertal maturation.
Varicocele (choice E) results in an increased testicular temperature, decreasing the count of normal, viable sperm.