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A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M.; 2013.

A.D.A.M. Medical Encyclopedia.

Hemophilia B

Christmas disease; Factor IX hemophilia

Last reviewed: February 24, 2014.

Hemophilia B is a hereditary bleeding disorder caused by a lack of blood clotting factor IX. Without enough factor IX, the blood cannot clot properly to control bleeding.

Causes

Hemophilia B is caused by an inherited X-linked recessive trait, with the defective gene located on the X chromosome.

Females have two copies of the X chromosome. If the factor IX gene on one chromosome does not work, the gene on the other chromosome can do the job of making enough factor IX.

Males have only one X chromosome. If the factor IX gene is missing on a boy's X chromosome, he will have Hemophilia B. For this reason, most people with hemophilia B are male.

If a woman has a defective factor IX gene, she is considered a carrier. This means the defective gene can be passed down to her children. Boys born to such women have a 50% chance of having hemophilia B. Their daughters have a 50% chance of being a carrier.

All female children of men with hemophilia carry the defective gene.

Risk factors for hemophilia B include:

Symptoms

The severity of symptoms can vary. Bleeding is the main symptom. It is often first seen when the an infant is circumcised. Other bleeding problems usually show up when the infant starts crawling and walking.

Mild cases may go unnoticed until later in life. Symptoms may first occur after surgery or injury. Internal bleeding may occur anywhere.

Symptoms can include:

Exams and Tests

If you are the first person in the family to have a suspected bleeding disorder, your doctor will order a series of tests called a coagulation study. Once the specific defect has been identified, other people in your family will need tests to diagnose the disorder.

Tests to diagnose hemophilia B include:

Treatment

Treatment includes replacing the missing clotting factor. You will receive factor IX concentrates. How much you get depends on:

To prevent a bleeding crisis, people with hemophilia and their families can be taught to give factor IX concentrates at home at the first signs of bleeding. People with severe forms of the disease may need regular, preventive infusions.

If you have severe hemophilia, you may also need to take factor IX concentrate before surgery or certain types of dental work.

You should get the hepatitis B vaccine. People with hemophilia are more likely to get hepatitis because they may receive blood products.

Outlook (Prognosis)

With treatment, most people with hemophilia are able to lead a relatively normal life.

If you have hemophilia, you should have regular check ups with a hematologist.

Possible Complications

Complications can include:

  • Long-term joint problems, which may require a joint replacement
  • Bleeding in the brain (intracerebral hemorrhage)
  • Thrombosis due to treatment

When to Contact a Medical Professional

Call your health care provider if:

  • Symptoms of a bleeding disorder develop
  • A family member has been diagnosed with hemophilia B
  • If you have hemophilia B, and you plan to have children; genetic counseling is available

Prevention

Genetic counseling may be recommended. Testing can identify women and girls who carry the hemophilia gene.

Testing can be done during pregancy on a baby that is in the mother's womb.

References

  1. Carcao M, Moorehead P, Lillicrap D. Hemophilia A and B. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al., eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, Pa: Elsevier Saunders; 2012:chap 137.
  2. Scott JP, Montgomer RR. Hereditary clotting factor deficiencies (bleeding disorders). In: Kliegman RM, Stanton BF, St. Geme JW III, et al., eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 470.

Review Date: 2/24/2014.

Reviewed by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

What works?

  • Regular clotting factor replacement therapy to prevent joint disease in people with severe hemophilia A or BRegular clotting factor replacement therapy to prevent joint disease in people with severe hemophilia A or B
    Hemophilia A and B are X‐linked inherited bleeding disorders, in which the major clinical problem is repeated bleeding into joints. As this disorder progresses, joints become deformed and movement limited. Current therapy for treating and preventing bleeding includes plasma‐derived or recombinant clotting factor concentrates. This review includes six randomised controlled trials. Two compare the regular use of clotting factor concentrates to prevent joint bleeds with their use 'on demand'. Four compare different regimens of regular use in children and adults with hemophilia. It was clearly evident that preventative therapy, as intravenous infusion of factor concentrate repeated more times a week and started early in childhood was able to reduce joint deterioration as compared to treatment administered after bleeding occurred. This favourable effect is due to a consistent reduction in total bleeds and hemarthrosis (bleeding into joints) and leads to a significant improvement in quality of life. Preventative therapy is linked to an increased factor usage and cost of treatment. We found weaker evidence (due to lack of data) to show preventative therapy reduced joint deterioration when treatment is started after joint damage has been established. Further studies are needed to establish the best preventative regimen, i.e. for example starting time, dosage frequency, minimally effective dose.
See all (2) ...

Figures

  • X-linked recessive genetic defects - how boys are affected.
    X-linked recessive genetic defects - how girls are affected.
    X-linked recessive genetic defects.
    Blood cells.
    Blood clots.

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