What is hemophilia?
Hemophilia is an inherited bleeding, or coagulation, disorder. Children with hemophilia lack the ability to stop bleeding because of the low levels, or complete absence, of specific proteins, called factors, in their blood that are necessary for clotting. Proper clotting of blood helps prevent excessive bleeding.
What are the different types of hemophilia?
There are many factors in the blood that are involved in the forming of clots to stop bleeding. A child with hemophilia is missing, or has a low supply of, one of the factors needed in order for the blood to clot. Two common factors that affect blood clotting are factor VIII and factor IX.
Hemophilia is classified by its level of severity. Hemophilia may be mild, moderate, or severe, depending on the level of the blood clotting factors in the blood.
The three main forms of hemophilia include the following:
Hemophilia A. This is caused by a lack of the blood clotting factor VIII; about 9 out of 10 people with hemophilia have type A disease. This is also referred to as classic hemophilia or factor VIII deficiency.
Hemophilia B. This is caused by a deficiency of factor IX. This is also referred to as Christmas disease or factor IX deficiency.
Hemophilia C. Some doctors use this term to refer to a lack of clotting factor XI.
von Willebrand disease. A large glycoprotein called von Willebrand factor binds to factor VIII to prevent it from being degraded in the circulation. The von Willebrand factor also binds to platelets (blood cells that control bleeding) and helps the platelets attach to the lining of a vein or artery. If von Willebrand factor is malformed, decreased, or absent, there is prolonged bleeding time because the platelets are unable to attach to the wall of the vessel and form a plug to stop the bleeding. If von Willebrand factor cannot bind to factor VIII, then factor VIII is rapidly degraded and becomes deficient in the circulation. This disease is similar to hemophilia, but is not usually called by this name. It is more common and usually milder than hemophilia.
What causes hemophilia?
Hemophilia types A and B are inherited diseases passed on to children from a gene located on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. A female carrier of hemophilia has the hemophilia gene on one of her X chromosomes. When a hemophilia carrier female is pregnant, there is a 50/50 chance that the hemophilia gene will be passed on. If the gene is passed on to a son, he will have the disease. If the gene is passed on to a daughter, she will be a carrier. If the father has hemophilia but the mother does not carry the hemophilia gene, then none of the sons will have hemophilia disease, but all of the daughters will be carriers.
In about one-third of the children with hemophilia, there is no family history of the disorder. It is believed that, in these cases, the disorder could be related to a new gene mutation. Tests are available to possible carriers to help determine whether or not they, in fact, carry the abnormal gene.
Carriers of the hemophilia gene usually have normal levels of clotting factors but may bruise easily, may bleed more with surgeries and dental work, and/or have frequent nosebleeds or excessive menstrual bleeding.
Hemophilia C usually does not cause problems, but some patients may have bleeding after surgery.
In von Willebrand disease, the genetics are more complicated. With von Willebrand disease, the missing protein, von Willebrand factor (vWF), is not on the X chromosome, but on a chromosome that is not gender determined; so, the disease can affect both males and females equally. Its inheritance is autosomal dominant, which means that a parent with the gene has a 50/50 chance to pass it on. In an autosomal dominant condition, if the gene is passed on to a child, the child will likely develop some symptoms.
Children with von Willebrand disease may have inherited the disorder or it is possible to have had the disease caused by certain medications, autoimmune disorders, kidney problems, and certain forms of cancer.
What are the symptoms of hemophilia?
Because hemophilia is a bleeding disorder, the most common symptom of the disorder is excessive, uncontrollable bleeding. Children with hemophilia do not bleed faster than normal children; they bleed for a longer time.
The severity of hemophilia is determined by the amount of clotting factors in the blood. Those affected with hemophilia that have levels greater than 5 percent (100 percent being average for unaffected children) usually experience bleeding only with major surgeries or tooth extractions. These children may not even be diagnosed until bleeding complications from a surgery occur.
Severe hemophilia is when the factor VIII or IX is less than 1 percent. Bleeding can occur in these children, even with the minimal activities of daily life, and bleeding may also occur from no known injury. Bleeding most often occurs in the joints and in the head.
Other symptoms of hemophilia include:
Bruising. Bruises can occur from small accidents, which can result in a large hematoma (a collection of blood under the skin causing swelling). For this reason, most diagnoses occur around 12 to 18 months of age, when the child is becoming more active.
Bleeds easily. A tendency to bleed from the nose, mouth, and gums with minor trauma, teeth brushing, and/or dental work is often an indication of hemophilia.
Bleeding into a joint. Hemarthrosis (bleeding into a joint) can cause pain, immobility, and eventually deformity if not medically managed properly. This is the most common site of complications due to hemophilia bleeding. These joint bleeds can lead to chronic, painful, arthritis, deformity, and crippling with repeated occurrences.
Bleeding into the muscles. Bleeding into the muscles can cause swelling, pain, and redness. Swelling from excessive blood in these areas can cause increased pressure on tissues and nerves in the area, resulting in permanent damage and/or deformity.
Bleeding in the brain from injury or spontaneously. Bleeding from injury, or spontaneously in the brain, is the most common cause of death in children with hemophilia and the most serious bleeding complication. A brain hemorrhage can occur from even a small bump on the head or a fall. Small bleeds in the brain can result in blindness, retardation, a variety of neurological deficits, and can lead to death if not recognized and treated immediately.
Other sources of bleeding. Blood found in the urine or stool may also be a symptom of hemophilia.
The symptoms of hemophilia may resemble other blood disorders or medical problems. Always consult your child's doctor for a diagnosis.
How is hemophilia diagnosed?
In addition to a complete medical history and physical examination, your child's doctor may perform numerous blood tests including clotting factor levels, a complete blood count (CBC), assessment of bleeding times, and/or DNA testing. Your child's doctor may also request details about your child's family history.
Treatments for hemophilia
Specific treatment for hemophilia will be determined by your child's doctor based on:
Your child's age, overall health, and medical history
Extent of the disease
Your child's tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
Treatment depends on the type and severity of the hemophilia. Treatment for hemophilia is aimed at prevention of bleeding complications (primarily head and joint bleeds). Treatment may include:
Immunizations may need to be given under the skin (subcutaneous) instead of in the muscle (intramuscular) to prevent deep muscle bleeds.
Joint hemorrhages may require surgery and/or immobilization. Rehabilitation of the affected joint may include physical therapy and exercise to strengthen the muscles around the area.
Before surgery, including dental work, your child's doctor may recommend factor replacement infusions to increase the child's clotting levels prior to the procedures. Your child may also receive the specific factor replacement infusions during and after the procedure to maintain the clotting factor levels and to improve healing and prevention of bleeding after the procedure.
Your child's doctor may also recommend the discontinuation of aspirin, and aspirin-containing products, since these products have been linked to bleeding problems.
Blood transfusions may be necessary if significant blood loss has occurred.
Proper dental hygiene is a preventive measure.
Prophylactic self-infusion of factor VIII or IX can allow a child with hemophilia to lead a near normal lifestyle.
The use of gene therapy to replace the defective genes that cause hemophilia is under study, and clinical trials are being conducted, according to the National Heart, Lung, and Blood Institute.
Long-term outlook for children with hemophilia
Hemophilia is a lifelong disease. With the advances of specific clotting factors in laboratories, prevention and treatment of bleeds is improving.
With careful management, informed decisions, and recognition of complications, many children with hemophilia can live relatively healthy lives with a normal lifespan.