Congenital hemophilia is a rare, X-linked bleeding disorder characterized by a deficiency in coagulation factor VIII (FVIII; hemophilia A) or factor IX (hemophilia B).1The partial or total absence of these factors results in spontaneous bleeding episodes, which occur primarily in joints, muscles, and, less commonly, soft tissues, as well as excessive bleeding following trauma or surgery.1 Here, F8 is linked to hemophilia B.