A Woman Whose Father Does Not Have Hemophilia Gives Birth

Multiple Choice

A woman whose father does not have hemophilia gives birth to a son with classic hemophilia. This woman is found to have only 15% of the normal amount of clotting factor VIII (the clotting factor males with hemophilia are missing) and does have abnormal blood-clotting issues. Which phenomenon or factor is most likely responsible for her abnormal clotting factor expression?

A) The X chromosome most commonly inactivated in her bone marrow is paternally derived.
B) The X chromosome most commonly inactivated in her bone marrow is maternally derived.
C) This woman is demonstrating reduced penetrance of an X-linked-recessive disorder.
D) This woman is demonstrating full penetrance of an X-linked-recessive disorder.