Genetics and Disease — MCQs

Question 311: In Kartagener syndrome, the cause of infertility is?

• A. Oligospermia
• B. Asthenospermia (Correct Answer)
• C. Undescended testis
• D. Epididymal obstruction

Explanation: ***Asthenospermia*** - In Kartagener syndrome, **dynein arms** in sperm flagella are defective, leading to **poor sperm motility**. - This severely impairs the sperm's ability to reach and fertilize an egg, resulting in **infertility**. *Oligospermia* - This refers to a **low sperm count** and is not the primary cause of infertility in Kartagener syndrome. - While overall semen quality can be affected, the central issue is the **lack of sperm movement**, not insufficient numbers. *Undescended testis* - Also known as **cryptorchidism**, this condition involves one or both testes failing to descend into the scrotum. - It leads to impaired sperm production due to higher intra-abdominal temperatures, but is unrelated to the **ciliary dysfunction** seen in Kartagener syndrome. *Epididymal obstruction* - This involves a blockage in the **epididymis**, preventing sperm from being ejaculated. - While it causes infertility, it is a structural problem and does not account for the **motility defects** seen in Kartagener syndrome.