SPARK THERAPEUTICS, SANGAMO THERAPEUTICS AND SALK INSTITUTE
Hemophilia is an inherited bleeding disorder that causes abnormal or exaggerated bleeding and poor blood clotting. Hemophilia A and Hemophilia B are inherited in an X-linked recessive genetic pattern, so males are commonly affected while females are usually carriers of the disease. Hemophilia A is caused by clotting Factor VIII deficiency and hemophilia B (Christmas disease) is caused by Factor IX deficiency. A subgroup of hemophilia B, which has the so-called Leyden phenotype, has severe hemophilia in . . .