Hemophilia is an inherited bleeding disorder. Children with hemophilia have problems with bleeding because of low levels or complete absence of specific proteins, called “factors,” in their blood that are necessary for prevention of excessive bleeding.
In the United States, about 20,000 people have hemophilia. People of all races and economic groups are equally affected. Each year, about 400 babies are born with hemophilia. The most common forms of hemophilia result from deficiencies of clotting factor proteins, factor VIII and factor IX. Both Factor VIII and Factor IX are necessary to form a clot.
- Hemophilia A: caused by a missing or reduced amount of the blood clotting protein Factor VIII
- Hemophilia B: caused by a missing or reduced amount of the blood clotting protein Factor IX
What Causes Hemophilia?
Hemophilia types A and B are inherited bleeding diseases passed on to children from defective genes located on the X chromosome. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Males (XY) have hemophilia when the gene for clotting factor VIII (Hemophilia A) or clotting factor IX (Hemophilia B) on the single X chromosome is affected.
A female carrier of hemophilia has the hemophilia gene on one of her X chromosomes and the normal gene on her other X chromosome. When a woman who is a carrier of the hemophilia gene becomes pregnant, there is a 50% chance that the child will get the X chromosome with the hemophilia gene. If the gene is passed onto the daughter, she will be a carrier.
If the father has hemophilia and the mother does not carry the hemophilia gene, then none of her sons will have hemophilia disease (because the mother has donated a normal X chromosome and the father has donated a normal Y chromosome). However, in this scenario, all of the daughters will be carriers because the mom donates her normal X chromosome and the father has donated his abnormal X chromosome with the abnormal gene present.
In about one-third of the children with hemophilia, there is no family history of the disorder. A new gene mutation, it is believed may be the cause of the disorder.
A complete medical and family history is taken and a physical examination is performed. Your child’s physician may perform numerous blood tests including clotting factor levels, a complete blood count (CBC) and possibly DNA testing.
What Are the Symptoms of Hemophilia?
The most common symptom of hemophilia is excessive, uncontrollable bleeding. Patients with hemophilia do not bleed faster than normal children; they bleed for a longer time.
The severity of symptoms in children with hemophilia depends on the severity of the disease.
Severe hemophilia is when factor VIII or factor IX clotting factor activity is less than 1%.
- Spontaneous bleeding can occur unrelated to injury and is most dangerous when it occurs in the head
- Joint bleeding is common
Moderate hemophilia is when factor VIII or IX clotting factor activity is 1–5%.
- Bleeding episodes are usually related to injury
- Joint bleeding can occur
Mild hemophilia is when factor VIII or IX clotting factor activity is 6–40%.
- Episodes of bleeding are usually related to surgery or dental extractions
- Joint bleeding is uncommon
Other symptoms of hemophilia include:
- Soft tissue bleeding
- Bleeding from the nose, gums or mouth
- Pain, swelling and limited mobility in the joints and muscles
- Blood found in the urine or stool, or vomiting blood
- Excessive bleeding following circumcision
How Is Hemophilia Treated?
While a cure for hemophilia is not currently available, the disorder may be managed effectively by doing the following:
- Treat bleeds early and appropriately
- Get an annual comprehensive checkup at the hemophilia treatment center
- Exercise to maintain healthy joints
- Early treatment of bleeds is important and can be done by intravenous clotting factor replacement. This can even be done at home. Factor replacement prevents serious complications and allows children to live active lives.
- The goal of factor replacement is to stop or prevent bleeding by increasing the level of the missing or decreased factor VIII or IX. Both factors VIII and IX are available as natural or synthetic (recombinant) powders that can be diluted in sterile fluid and infused directly into a vein.
- The Medical and Scientific Advisory Committee (MASAC) of the National Hemophilia Foundation recommends recombinant factor concentrate as the preferred method of treatment because it is not made from human blood.