What test is useful for detection of a female carrier of hemophilia A?

Question

Quizplus · Accepted Answer

Approximately 90% of female carriers of hemophilia A are detected using the ratio of factor VIII activity to VWF antigen.This is because VWF production is unaffected by factor VIII deficiency,so it should be normal in a female hemophilia A carrier,whereas the factor VIII activity will be less than that of VWF.Thus a discrepancy exists in the concentration of these two proteins.

What Test Is Useful for Detection of a Female Carrier