Question

A healthy 31-year-old woman comes to the office because she and her husband desire a second child. The husband has Klinefelter syndrome and is infertile, and the patient's son, who was conceived via donor insemination, was recently diagnosed with glycogen storage disease type II (Pompe disease). This rare autosomal recessive disease is known to affect 1 in 40,000 of the general population. What is the probability that the patient would have a second affected child with a new, healthy sperm donor?

A. 1/4
B. 1/240
C. 1/400
D. 1/800
E. 1/40,000
F. 1/160,000

Answer 1

The probability of the patient having a second affected child with a new, healthy sperm donor is 1/4.

Step-by-step explanation:

The probability of the patient having a second affected child with a new, healthy sperm donor can be calculated using the principles of autosomal recessive inheritance. Since the husband has Klinefelter syndrome, he cannot pass on an affected allele to his offspring. The patient herself is healthy and not a carrier for Pompe disease. Therefore, the probability of having an affected child is 0. The probability of having an unaffected child is 1. So, the probability of having an affected child is 0 (1/0). Therefore, the correct answer is A. 1/4.