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HEMOPHILIA B - factor IX deficiency (Christmas disease)          See also Hemophilia A

A sex linked disorder that is clinically indistinguishable from hemophilia A.

a. Diagnosis: prolonged PTT & low Factor IX level

b. Management: Factor IX is replaced with fresh frozen plasma or, during dire emergencies, with prothrombin complex concentrates.

The calculated Factor IX requirement is based on the assumption of 1 unit of Factor IX/kg will increase the plasma level by 1%, or by 0.01 units/ml.

The level of Factor IX needed to control hemostasis is about 0.15 0.20 units/ml.