Hemophilia B

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 23, 2016
StartDiseasesHemophilia B

Hemophilia B is a form of hemophilia, a bleeding disorder in which blood clotting does not occur as it should. Hemophilia B is primarily diagnosed in childhood and is the result of a faulty gene, whether that gene is inherited or mutates before birth. One in 10 hemophiliacs have this form of the disorder, where there is not enough of a blood clotting protein called factor IX in their blood.

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Definition & Facts

Hemophilia occurs as a gene mutation usually discovered in early childhood. There are three forms of the disorder, hemophilia A, hemophilia B and hemophilia C. The three types are differentiated by the clotting protein missing from the blood, also called the coagulation factor.

Hemophilia B is the absence or insufficiency of a blood clotting protein called factor IX. Hemophilia B causes those suffering from the disorder to bleed for a longer period following injury than they would if they had sufficient factor IX in their blood.

The biggest issue for hemophiliacs is not usually that of small cuts on the skin. The bigger problem lies in internal bleeding in the body. This deep bleeding can damage tissues and organs, even causing death. The most vulnerable points on the body for this to start is at knees, elbows and ankles. There is no cure for hemophilia B. Self-care and treatment help people affected by the disorder lead active, healthy and productive lives.

Symptoms & Complaints

Hemophilia B symptom severity ranges from person to person, depending upon their clotting factor IX levels. People who have some factor IX will experience less risk and symptoms than those with no factor IX.

For those with only mild reduction of factor IX, bleeding may occur only following surgery or other trauma. Those with greater deficiency can bleed spontaneously without clear trigger. Some signs and symptoms of bleeding spontaneously as a result of hemophilia B include:

For people with hemophilia B, or those suspected of having the disorder, the following symptoms are indications of an emergency:

Causes

To stop bleeding in the body and from wounds, blood cells pool together to form a clot. This is the process in a normal person's body, along with further clotting facilitation of blood platelets and plasma proteins. But when hemophilia exists, these processes do not occur as they should.

Hemophilia B is either inherited or caused by a spontaneous mutation. About 30 percent of hemophilia patients have the disorder as a result of mutation, with no family members sharing the condition. The remaining 70 percent have family history of the disorder.

Hemophilia B is caused by an insufficiency of clotting factor IX and is the second most common type of hemophilia. Like hemophilia A, this form passes from mother to son and cannot be passed from fathers. Almost all hemophilia B patients are boys, although females can carry the disorder with little to no symptoms, passing it on to their sons.

Diagnosis & Tests

Many male babies are diagnosed as having hemophilia B after circumcision, when prolonged bleeding occurs. Boys who are uncircumcised may be diagnosed after they are seen for excessive bruising without explanation, just as they become more mobile in crawling or walking. Most children with hemophilia B are diagnosed by age 2, as the first episode of bleeding has likely occurred by that time.

When there is a family history of hemophilia, a fetus can be diagnosed while still in utero. The testing can be dangerous for the baby, so administering the diagnostic tests should be weighed according to individual risks and benefits. Sometimes surgery or other bleeding episode leads to the first awareness of mild hemophilia.

A simple blood test can provide a diagnosis of clotting-factor deficiency for both children and adults. These tests can reveal the length of time it takes for the blood to clot, the levels of clotting factor in the blood, and whether or not the clotting factor exists at all in the blood.

Treatment & Therapy

Despite a hemophilia B diagnosis, a relatively normal life can be experienced. Patients should just maintain ongoing treatment as prescribed and ensure treatment is in place and pursued for bleeding episodes. As part of ongoing treatment, your doctor may recommend one or more of the following courses of care:

When it comes to treating a bleeding crisis, bleeding may only stop when an infusion of donor blood is administered to provide clotting factor IX, or recombinant clotting factor is provided.

Prevention & Prophylaxis

While the condition itself cannot be prevented, therapies and treatments can be applied to prevent bleeding episodes. Damage to muscles, organs and joints can be prevented through administration of clotting factor, as can excessive bleeding from procedures or surgery. Prophylactic therapy is an administration of factor IX about three times per week for general prevention, just as the factors can be infused before a high risk activity.