Question

Which of the following true regarding Hemophilia A ?

• A. Serum levels of factor VIII are decreased
• B. Deficiency of factor IX
• C. PT increased
• D. FIT decreased

Answer 1

The Correct Option is A

Step 1: Match each clotting factor to its hemophilia type. Factor VIII deficiency equals hemophilia A; factor IX deficiency equals hemophilia B.

Step 2: Since the patient has hemophilia A, the missing protein is factor VIII, so its measured plasma level falls. This validates the first option.

Step 3: Factor VIII belongs to the intrinsic clotting cascade, which the PTT (aPTT) tests. A deficiency therefore prolongs the PTT rather than shortening it, so the option claiming PTT is decreased is false.

Step 4: PT reflects the extrinsic and common pathways and is unaffected in hemophilia A, so the option stating PT is increased is also incorrect. Deficiency of factor IX is a different disease entirely.

\[\boxed{\text{Serum levels of factor VIII are decreased}}\]