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Hemophilia

Hemophilia is a genetic bleeding disorder. People who have hemophilia have a deficiency or an absence of a coagulation protein so there is no blood-clotting factor. Bleeding is mostly in the joints, such as the knee, elbow, or ankle, but it can occur anywhere in the body. People with hemophilia bleed longer then normal people. The severity of hemophilia can vary; Hemophilia A and Hemophilia B are the most common disorders. Hemophilia A or classic Hemophilia is observed in 80 percent of hemophiliacs and is a deficiency or absence of Factor 7. In the second most common is Hemophilia B, it’s an an inherited disorder in which one of the proteins needed to form blood clots is missing or reduced. In about 30% of cases, there is no family history of the disorder. Hemophilia was identified as early as biblical times. Doctors in medieval times were familiar with it as well. In 1803, a Philadelphia doctor published the first description of hemophilia in the United States. But it was not until 30 years later that hemophilia became widely recognized mainly because it was passed into the royal families. Queen Victoria of England passed it to her descendants throughout the royal houses of Europe. Most famously to Tsarovitch Alexander of the last Russian royals (below). About eighty percent of all cases of hemophilia have an identifiable family history of the disease. In other instances, it may be because of a spontaneous mutation.

Inheritance is controlled by a recessive sex-linked factor carried by the mother on the X chromosome, in the case of the royals; the Tsarina Alexandra passed it to her son. A probability of one in two exists that each boy born to a normal male and a carrier female will be hemophiliac and the same chance that each girl of this union will be a carrier. Of the children of a hemophiliac male and a normal female, all the girls will be carriers and all the boys will be normal. Males cannot transmit the disability, and female carriers are free of the disease (see diagram below).

In people with hemophilia A, fibrin is not made properly, so firm blood clots do not form in the wound, and bleeding continues. There are two major processes involved in blood clotting. The first part has to do with platelets, which go to where the blood vessel has ruptured, and they cover the hole to make a plug. This is the first step of making a clot. The plug is only temporary, because platelets can easily fall off. The platelets soon rupture and release chemicals that attract more platelets and make them sticky. The chemicals released by the rupturing platelets also activate various clotting factors, which are proteins in the blood. The next step is that fibers form from the activated proteins and mix with the platelets. The fibers are like a net, and they make the clot stronger. The substance that makes the fibers is called fibrinogen. There are twelve factors that work together to make the fibrinogen. People with hemophilia have a problem with one or more of those factors.

Babies with hemophilia usually have no difficulty during the birth process, however circumcision may produce prolonged bleeding. During the first few months of life, a baby with hemophilia has few problems because ones ability to move around is limited. As the baby learns to walk one will fall and sustain many small, superficial bumps and bruises. Bleeding into soft tissue area of the arms and legs is frequent and usually not serious. Superficial bruises are seen easily and are often raised, but usually do not require treatment. As a child with hemophilia matures, one is more active and will have more bleeding episodes. The first sign of bleeding deep in a muscle may be a reluctance to use the limb. The child may become irritable as bleeding continues. Early treatment with clotting factor usually prevents the pain from becoming severe, and since only a small amount of blood will have leaked into the joint space, recovery will be quick, although the joint will sustain some permanent damage. Apart from pain, improperly treated bleeding irritates the joint surface, which eventually leads to arthritis. A large volume of blood, which results from delayed treatment, takes longer to re-absorb into the body. Early treatment of each bleeding episode will limit the amount of irritation and reduce the risk of arthritis. Strong muscles protect joints from some bleeding episodes. Therefore it is suggested that people with hemophilia exercise regularly.

The most significant advances in hemophilia treatment have been made in the last four decades. Baxter Healthcare Corporation introduced the first commercially available plasma-derived factor concentrate in the mid-1960s. In the early 1970s, home treatment of hemophilia became widely available, offering people with hemophilia greater independence and reduced hospital stays.

Today, as a result of new combinations of genetic material, DNA technology and the discovery of the genes that control production of factor VIII have led to the development of recombinant factor concentrates that do not rely on plasma at all. Patients should discuss with their physicians which factor VIII replacement therapy is best for them. Inhibitors are proteins called antibodies that are made by our immune system to defend us from harmful disease. When our immune system identifies a foreign substance, it makes antibodies that will specifically recognize that substance and destroy it. In some individuals with severe hemophilia, the factor VIII replacement therapy is identified as a foreign substance by their immune system. If this happens, their immune system will make antibodies against factor VIII. These antibodies will inhibit the ability of the factor to work in the clotting process. The higher the antibody or inhibitor level, the more factor VIII replacement therapy it takes to overcome the inhibition and produce clotting. This can complicate the treatment of a bleed. The good news is that there are different types of therapies available to successfully treat most individuals who develop inhibitors.

Bibliography: Hemophilia, Encarta Online, Wikipedia, Sciencecases.org, MacquarieDictionary.com.au, dictionary.reference.com

Dictionary: Coagulation is a complex process by which blood forms clots. Genetic when living things inherit traits from their parents. Factor 7 helps form a protective blood clot. Spontaneous mutations are changes in the DNA sequence of a cell's genome and are caused by radiation, viruses, ect. X chromosome is one of the two sex-determining chromosomes in many animal species. Fibrin is a fibrous protein involved in the clotting of blood. Fibrinogen is a protein in the blood plasma that is essential for the coagulation of blood.

The passing of Hemophilia through the Royal Family of Britain.