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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 A

Factor VIII deficiency

Last reviewed: February 24, 2014.

Hemophilia A is a hereditary bleeding disorder caused by a lack of blood clotting factor VIII. Without enough factor VIII, the blood cannot clot properly to stop bleeding.

Causes

Hemophilia A 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. So if the factor VIII gene on one chromosome does not work, the gene on the other chromosome can do the job of making enough factor VIII.

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

If a woman has a defective factor VIII 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 A. 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 A include:

Symptoms

The severity of symptoms vary. Bleeding is the main symptom of the disease. It is often first seen when an infant is circumcised. Other bleeding problems are seen 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 A include:

Treatment

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

Mild hemophilia may be treated with desmopressin (DDAVP), which helps the body release factor VIII that is stored within the lining of blood vessels.

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

Depending on the severity of the disease, DDAVP or factor VIII concentrate may be given before having dental extractions or surgery in order to prevent bleeding.

You should get the hepatitis B vaccine. People with hemophilia are more likely to get hepatitis because they may receive blood products. Patients who develop an inhibitor to factor VIII may require treatment with other clotting factors such as factor VIIa, which can help with clotting, even without any factor VIII.

Support Groups

You can ease the stress of illness by joining a hemophilia support group. Sharing with others who have common experiences and problems can help you not feel alone.

Outlook (Prognosis)

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

If you have hemophilia, you should have regular checkups 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:

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?

  • Treatments for acute bleeds in people with acquired hemophilia ATreatments for acute bleeds in people with acquired hemophilia A
    Acquired hemophilia A is a rare but severe bleeding disorder caused by the autoantibody directed against factor VIII (FVIII, a blood clotting protein) in patients with no previous history of a bleeding disorder. This bleeding disorder occurs more frequently in the elderly and may be associated with several other conditions, such as solid tumours, autoimmune diseases, or with drugs; it is also sometimes associated with pregnancy. However, in about half of the cases the causes are unknown. Bleeding occurs in the skin; mucous membranes; and muscles; with joint bleeds being unusual. Therapies for acquired hemophilia A include treatments to stop acute bleeds and to destroy the FVIII autoantibodies. Acute bleeds can be treated with recombinant activated FVII or activated prothrombin complex concentrate (aPCC). If these are unavailable, FVIII concentrates or 1‐desamino‐8‐D‐arginine‐vasopressin (DDAVP) fresh frozen plasma can be attempted; however, these last two options are not usually effective, and it is not known if one of these products is better than the other.
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