Which of the following true regarding Hemophilia A

* Hemophilia is an X linked disorder of coagulation caused by the deficiency in a circulating plasma protein. Hemophilia A is caused by the deficiency of factor VIII, and hemophilia B is caused by the deficiency of factor IX. * It is PTT which is affected (increased) and not PT (unaffected). * Factor VIII is involved in the intrinsic pathway which is measured by PTT and not in extrinsic pathway which is measured as PT. * Bleeding is the common manifestation of hemophilia and the common bleeding manifestations are hemahoses, hematomas, mucocutaneous bleeding, intracranial bleeding, hematuria and pseudotumor. REF : HARRISONS 21ST ED