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.
In the US, there are about 18,000 people with hemophilia.
What are the different types of hemophilia?
There are many factors in the blood that are involved in the function of forming 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 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 upon the level of the blood clotting factors in the blood.
The three main forms of hemophilia include the following:
- hemophilia A – caused by a lack of the blood clotting factor VIII; approximately 85 percent of hemophiliacs have type A disease.
- hemophilia B – caused by a deficiency of factor IX.
- von Willebrand disease – a part of the factor VIII molecule known as von Willebrand factor or ristocetin cofactor is reduced. The von Willebrand factor involves helping the platelets (blood cells that control bleeding) attach to the lining of a vein or artery. This missing factor results in prolonged bleeding time because the platelets are unable to attach to the wall of the vessel and form a plug to stop the bleeding.
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.
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. It is believed that approximately 2 percent of the US population suffers from this type of bleeding disorder.
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. Hemophiliacs 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 with these children with the minimal activity 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:
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 from injury or bleeding in the brain
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 physician for a diagnosis.
How is hemophilia diagnosed?
In addition to a complete medical history and physical examination, your child’s physician 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 physician may also request details about your child’s family history.
Treatments for hemophilia:
Specific treatment for hemophilia will be determined by your child’s physician 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:
- Parents may want to purchase soft toys with rounded corners for young children. Padded clothing and helmets may be necessary for the child that is learning to walk or becoming more active. Contact sports in school should be evaluated for risks of injury to the child.
- Immunizations may need to be given under the skin (subcutaneous) instead of in the muscle (intra muscular) 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 physician 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 physician 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.
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.
Source: Lucile Packard Children’s Hospital at Stanford