Hemophilia B

Hemophilia B, historically known as Christmas disease, is a rare, inherited bleeding disorder caused by a quantitative deficiency or functional defect in coagulation factor IX due to pathogenic variants in the *F9* gene Deficient factor IX impairs the intrinsic pathway of the coagulation cascade and hinders adequate thrombin generation, predisposing patients to prolonged or abnormal hemorrhage Clinical manifestations correlate with residual factor activity and range from excessive bleeding follo...

Hemophilia B, historically known as Christmas disease, is a rare, inherited bleeding disorder caused by a quantitative deficiency or functional defect in coagulation factor IX due to pathogenic variants in the *F9* gene Deficient factor IX impairs the intrinsic pathway of the coagulation cascade and hinders adequate thrombin generation, predisposing patients to prolonged or abnormal hemorrhage

Hemophilia B, historically known as Christmas disease, is a rare, inherited bleeding disorder caused by a quantitative deficiency or functional defect in coagulation factor IX due to pathogenic variants in the *F9* gene

Transmitted in an X-linked recessive pattern, it predominantly affects males, although heterozygous females may also exhibit bleeding symptoms depending on their circulating factor activity

Transmitted in an X-linked recessive pattern, it predominantly affects males, although heterozygous females may also exhibit bleeding symptoms depending on their circulating factor activity Clinical manifestations correlate with residual factor activity and range from excessive bleeding following invasive procedures or trauma to recurrent, spontaneous hemarthroses, deep muscle hematomas, and potentially fatal internal or intracranial hemorrhages