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.
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 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.
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:
The symptoms of hemophilia may resemble other blood disorders or medical problems. Always consult your child's doctor for a diagnosis.
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.
Specific treatment for hemophilia will be determined by your child's doctor based on:
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:
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.
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.
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