Hemophilia is a genetic disease that prevents blood from clotting normally.
At Seattle Cancer Care Alliance (SCCA), our expert team of doctors works closely with Bloodworks Northwest to provide comprehensive diagnostic and treatment options for people with hemophilia.
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What is hemophilia?
Hemophilia is a deficiency of factor VIII (8) or factor IX (9). These proteins, or clotting factors, activate blood clotting. People born with too little factor VIII have hemophilia A. Those without enough factor IX have hemophilia B.
Hemophilia ranges from mild disease, which may be diagnosed in later childhood or adulthood if there is no family history, to severe disease, which is usually diagnosed by age 2.
The genes for both factor VIII and factor IX are on the X chromosome. Males, who typically have an X and a Y chromosome, and females, who typically have two Xs, can both carry the gene that causes the disease. Males are usually more severely affected. Females usually have milder symptoms and may have no symptoms at all. Anyone with a hemophilia gene can pass it on to their children.
Symptoms and diagnosis of hemophilia
People with mild hemophilia bleed more than expected during surgery or dental procedures or after an injury. They rarely have bleeding for no obvious reason.
Patients with moderate and severe hemophilia (factor levels less than 5 percent of normal) can have recurrent bleeding into their joints and life-threatening internal bleeding, including into the brain — even in situations that wouldn’t cause bleeding in a person with healthy clotting.
Doctors most often diagnose hemophilia after a bleeding episode or due to a family history of the condition. In some cases, a pre-surgical blood test (partial thromboplastin time, PTT) might detect it. This screening test measures how long blood takes to clot. More specific tests can determine whether a long clotting time is due to hemophilia.
A more common, usually milder, bleeding disorder called von Willebrand disease may resemble hemophilia. It is caused by problems with a clotting protein called von Willebrand factor. If your doctor suspects you might have von Willebrand disease, they will order tests to confirm it because treatment for bleeding disorders depends on which protein is missing or defective.
The main treatment for hemophilia is replacement therapy with concentrated clotting factors. Regular infusions of blood clotting factor, which can be done at home, allow people with severe hemophilia to lead normal, active lives. For people with milder disease who do not need regular infusions, replacement therapy is given before surgeries and other procedures that might cause bleeding or in response to bleeding episodes.
If you have mild hemophilia A, doctors may prescribe the medicine desmopressin acetate (DDAVP). It causes cells in the lining of your blood vessels to release stored factor VIII, increasing the level in your blood. You may also need medicines that prevent the breakdown of blood clots (antifibrinolytic therapy).
Some people with hemophilia develop antibodies to transfused clotting factors. The antibodies destroy the factors, making them less effective. If doctors detect antibodies to factor VIII in your blood, they may prescribe a special high-dose regimen of factor to decrease the antibody response and use alternative treatments to treat bleeding.
For more information about hemophilia, visit the National Hemophilia Foundation website.