If a father is affected by an X-linked condition and the mother is a carrier,what is the probability of their children being affected?

Question

Quizplus · Accepted Answer

In an X-linked condition, males have one X chromosome and females have two X chromosomes. If the father is affected, he must have inherited the disease-causing allele from his mother, and all his daughters will be carriers. If the mother is a carrier, she has one copy of the disease-causing allele and one copy of the normal allele on one of her X chromosomes. She will pass one of these alleles to each of her children. Thus, there is a 50% chance that each of her sons will inherit the disease-causing allele and be affected, and a 50% chance that each of her daughters will inherit the normal allele from her mother's unaffected X chromosome and the disease-causing allele from her carrier X chromosome, making her a carrier as well.

If a Father Is Affected by an X-Linked Condition and the Mother