(Hemophilia A–Factor VIII Deficiency, Classic Hemophilia Hemophilia B–Factor IX Deficiency, Christmas Disease)
Hemophilia is a group of inherited bleeding disorders caused by reduced amounts of specific clotting factors.
The most common types of hemophilia are:
- Hemophilia A (also called Classic Hemophilia)–caused by too little factor VIII–1 in 10,000 males. Accounts for 80% of all hemophilia.
- Hemophilia B (also called Christmas Disease)–caused by too little factor IX–1 in 34,000 males.
Hemophilia is caused by an inherited sex-linked recessive gene. The malfunctioning gene is located on the X chromosome.
Females carry two copies of the X chromosome, and if they have a gene on one X chromosome not functioning, while the other gene on the second X chromosome is functioning, the one gene that functions makes enough of the product needed to prevent disease. Females carry the abnormal gene, but generally do not get the disease.
Males, however, carry only one X chromosome, so if they inherit the X chromosome with the malfunctioning gene, they do not have another X chromosome to compensate and they get the disease, in this case hemophilia.
Females with one hemophilia gene are carriers of this trait. The risk for their male offspring to inherit the gene (and therefore the disease) is 1 in 2 or 50%; the chance that their female offspring will inherit the gene is also 50% and these offspring will be carriers like their mothers.
It is possible for a female to have hemophilia only if she inherits the gene from both her mother (a carrier) and her father (who would have hemophilia). And all female children of a male hemophiliac are carriers of the trait.
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors include:
- Family members with hemophilia
- Family history of bleeding disorders
- Sex: Male
The severity of symptoms can vary with this disease, and the severe forms become apparent early on. Bleeding is the hallmark of the disease and sometimes, though not always, occurs if an infant is circumcised. Additional bleeding manifestations appear when the infant becomes mobile.
Bleeding can occur after injury, producing excessive bruising after a relatively minor trauma, after a cut, or after extraction of teeth. Bleeding into joints (hemarthrosis) is a common sign. Intestinal bleeding may produce bloody stools or, if it occurs in the small intestine, black, tarry stools.
Mild cases may go unnoticed until later in life when they occur in response to surgery or trauma. Internal bleeding may happen anywhere.
Symptoms for Hemophilia A and B may include:
- Hot, swollen, sore, stiff, and/or deformed joints
- Bleeding into muscles
- Bleeding into the intestinal tract
- Bloody stools
- Bloody urine
- Difficulty stopping bleeding after minor cuts or bumps
- Heavy bleeding even after simple surgical or dental procedures
Symptoms for Hemophilia B may include:
- Excessive bleeding after circumcision
Coagulation studies involving many tests are performed if the person tested is the first one in the family to have a bleeding disorder. Once the defect has been identified, other family members will need less testing to diagnose the disorder.
The doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests may include:
- Tests of bleeding time
- Blood tests to measure the amounts of clotting factors present
- If you have hemophilia, you can be given blood factor concentrate through an IV. You'll be tested frequently to monitor your factor levels. When your factor levels drop too low, you'll be given a dose of factor concentrate.
- Mild hemophilia may be treated with infusion of the medications cryoprecipitate or desmopressin (DDAVP), which causes release of blood factor concentrate that is stored within the body on the lining of blood vessels.
- To prevent a bleeding crisis, people with hemophilia and their families can be taught to administer blood factor concentrate at home at the first signs of bleeding. People with severe forms of the disease may need regular (prophylactic) infusions.
- Immunization with hepatitis B vaccine is necessary because of the increased risk of exposure to hepatitis due to frequent infusions of blood products. Before the ability to screen blood products for HIV, hemophiliacs also were at greatly increased risk for HIV infection, and in that population, illness and death due to HIV infection were significant. Similarly, many patients with hemophilia contracted hepatitis C prior to 1992, when screening for this vrus in blood products was introduced.
- Patients who develop an inhibitor to a particular factor may require treatment with other clotting factors, which can aid clotting.
People who have hemophilia should avoid situations that might cause bleeding. They should be conscientious about dental care so they won't need to have teeth extracted. People who have hemophilia should also avoid certain drugs that can aggravate bleeding problems:
- Certain analgesics, such as nonsteroidal anti-inflammatory drugs (NSAIDS) (eg, Tylenol, Ibuprofen)
Genetic counseling is available to obtain a detailed family history and to discuss risks and available testing for family members.