If a man with classic hemophilia (X-linked recessive) has children with a woman who is a carrier for the disorder, what is the expected risk pattern?
A)All sons will be unaffected; all daughters will be carriers.
B)All sons will be carriers; all daughters will be affected.
C)All sons have a 50% risk of the disorder; daughters will all either be affected or carriers.
D)All sons will be carriers; daughters have a 50% chance of being a carrier and a 50% chance of being unaffected.

Question

Quizplus · Accepted Answer

Because the disorder is X-linked recessive, sons cannot inherit the gene or the disorder from their fathers (their fathers gave them a Y chromosome). Sons can inherit the gene from their carrier mothers, making their risk for having the disorder 50%. All daughters will at least be carriers because they must inherit the gene from their fathers. If the daughters also inherit the gene for the disorder from their mothers, they will be affected. There is no "carrier status" for sons. They are either affected or do not have the gene.

If a Man with Classic Hemophilia (X-Linked Recessive) Has Children