Hemophilia is a group of bleeding disorders. The two most common types are Hemophilia A (or classic hemophilia) and Hemophilia B (or Christmas disease).
The F8 (Factor VIII) gene produces the protein antihemophilic factor (AHF) in humans.This protein is essential for routine blood clotting functions. In individuals with hemophilia A, this protein is absent or dysfunctional. For those with the less common hemophilia B, Factor IX is the gene responsible.
Symptoms of the disorder:
- Severe nosebleeds
- Easy bruising
- Blood in urine (hematuria) /stools
- Heavy bleeding/hemorrhage after bumps, dental work, minor cuts, or other trauma
- Joint pain
- Heavy menstrual bleeding in women who are carriers
- Damage to joints (including elbows, knees, and ankles)
- Damage to muscles, causing significant scarring and pain
- Severe anemia as a result of blood loss
- Bleeding in digestive system
- Bleeding inside head (intracranial hemorrhage)
- Compartment syndrome (develops when bleeding in muscles puts pressure on the arteries and nerves within, resulting in serious limb damage)
Hemophilia is caused by a sex-linked mutation-that is, a mutation to genes that are carried on either the X or the Y chromosomes. Both types of hemophilia discussed are X-linked recessive traits.Therefore, females are usually only carriers, as they have two X chromosomes. In order for a female to have hemophilia, both of her parents must pass on the faulty genes. Males, on the other hand, have only one X chromosome, and thus if a male inherits the faulty gene, hemophilia will develop.
It is possible for a new genetic mutation to occur-that is, the person gets hemophilia even if neither parent carries a genetic mutation.
Detection of Carriers
Carriers of hemophilia are detected by a process of carrier testing. These tests may involve:
- Creating a family tree. A genetic counselor or physician may help a woman create a detailed family history called a pedigree chart in order to determine information for three generations. This chart would aid in identifying possible carriers within the family.
- Factor levels can be tested. Factor level tests, accurate 70% to 90% of the time in determining carrier status, involve the testing of the blood of the woman. On average, carriers have lower levels of factors 8 or 9 than women who are not carriers.
- DNA testing is still the most accurate method. For this test, DNA of the tested is examined for genetic changes that could cause hemophilia. The two types available are direct mutation testing, and linkage (indirect testing).
- Prenatal testing involves testing a small amount of amniotic fluid, blood from the umbilical cord or placenta, and can be done early in the pregnancy.
Hemophilia can be treated by injecting AHF (isolated from donated blood) into the hemophiliac (the AHF is slowly injected or dripped into the veins). The donated blood must be meticulously screened and scrutinized for infectious diseases, however the AHF injections relieve the most severe effects of the disorder. With appropriate treatment, hemophiliacs can live relatively normal lives.
Even though gene therapy remains a great hope, so far there is no workable cure for hemophilia. In a small number of hemophiliacs with liver transplants, their hemophilia was completely cured, due to the clotting factor being made in the liver. Transplants, however, are much too risky to be used as a cure.
Another possible cure is fetal hepatocyte transplantation. Fetal hepatocytes are the liver cells of an aborted fetus. These cells can function as normal liver cells would and can be grown in a laboratory. As the scientists research, they hope that these cells can eventually be placed in the body of a hemophiliac and thus produce the clotting factor for the affected person.
Some precautions to take are:
- Avoid taking nonsteriodal anti-inflammatory drugs and aspirins (these may contain blood thinners).
- Get vaccinated with the hepatitis B vaccine.
- Avoid circumcising male offspring of women known to be carriers until the infant has been tested for hemophilia.
- Carry identification information identifying those with the disorder.
- Avoid activities with a high collision risk.
- Take extra care to protect the head from injury.
- Be aware of the effects of activities with high impact.
- Practice good dental care to reduce the risk of major dental work.
So far, there are no guidelines as to how to prevent hemophilia. However, talk to genetic counselors if you have a family history of the disease so that you can calculate the risk for potential offspring.
- Hemophilia earned the nickname “royal disease” or “disease of kings” because Queen Victoria passed on the disorder to her son Leopold who in turn passed it through many royal lineages of Europe.
- Hemophilia B is also called Christmas disease. The name originates from the first patient reported to have it, a man named Stephen Christmas.
- The disease was first called haemorrhaphilia.
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