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Hemophilia B
Other Resources UpToDate PubMed

Hemophilia B

Contributors: Joon B. Kim MD, Eric Ingerowski MD, FAAP, Michael W. Winter MD
Other Resources UpToDate PubMed


Hemophilia B, also known as Christmas disease, is a bleeding disorder due to factor IX deficiency. It is less common than hemophilia A and is also an X-linked autosomal recessive disorder that occurs most commonly in males.

Hemophilia B is characterized by prolonged bleeding following injuries, surgical procedures, and dental extractions. It can present with variable phenotypes. In a small percentage of female carriers, it may present in a milder form. Onset depends on severity of phenotype, but bleeding episodes may begin in early childhood and adolescence. More severe forms frequently present with spontaneous hemorrhage. Left untreated, hemophilia B may be fatal (intracranial hemorrhage) or result in severe motor impairment or paralysis (chronic joint disease).

Rarely, hemophilic pseudotumors may result from destruction of bone at sites of repeated bleeding. They may cause swelling and restricted movement.

Related topic: hemophilia A


D67 – Hereditary factor IX deficiency

41788008 – Hereditary factor IX deficiency disease

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Vitamin K deficiency – Factor 2, 7, and 10 will also be low.
  • Glanzmann thrombasthenia
  • Von Willebrand disease
  • Hemophilia A – Clinically similar to hemophilia B; factor VIII deficiency.
  • Coagulation factor deficiency (eg, Factor V deficiency, 7, 10, 11)
  • Fibrinogen deficiency
  • Scurvy – Bleeding is primarily mucosal, not musculoskeletal.
  • Disseminated intravascular coagulation – Usually has decreased platelet count.
  • Bruise of child abuse – Normal coagulation laboratory results.
  • Platelet dysfunction – Bleeding is primarily mucocutaneous, not musculoskeletal.
  • Fabry disease – Bleeding is primarily mucosal.

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Last Reviewed:01/30/2019
Last Updated:03/14/2023
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Hemophilia B
A medical illustration showing key findings of Hemophilia B : Easy bruising, Hemarthrosis, Ecchymosis, PTT prolonged
Copyright © 2024 VisualDx®. All rights reserved.