Hemophilia is a sex-linked hereditary bleeding disorder in which it takes a long time for the blood to clot and abnormal bleeding occurs. It is a hereditary blood coagulation disorder caused by a deficient activity of plasma protein factor thirteen and nine, which affects the clotting property of blood. A coagulation disorder is a disorder associated with platelets- blood cells essential for blood clotting. The platelets don’t function properly in the body of hemophiliacs. There are two types of hemophilia: hemophilia A and hemophilia B. This disease affects mostly males. Hemophilia A is the most common. Other names for it are classical hemophilia, and factor thirteen deficiency hemophilia. The bleeding disorder is caused by an inherited sex-linked recessive trait with the defective gene located on the X chromosome. The X chromosome refers to sex-linked. The recessive inheritance refers to the fact that the trait, hemophilia, is expressed only when the defective form of the gene alone is present. Females have two X chromosomes for their sex chromosomes. They must carry the defective gene on both to have hemophilia. They must have it on one to carry it, and are then able to pass it on to their offspring. Males have X and Y chromosomes for their sex chromosomes. They only have one X chromosome, therefore only require a single dose of the defective gene to express the deficiency. Fifty percent of the male offspring of female carriers have the disease, and fifty percent of their female offspring are carriers. This is why this disease mostly affects men. Severity of symptoms can vary with the disease, but bleeding is the central symptom. This includes internal bleeding, and bleeding into joints. The coagulation disorder is noticed when an infant is circumcised at birth. Additional bleeding may occur when the baby becomes mobile. Some mild cases of hemophilia may go unnoticed in life. The risk factors of hemophilia are having a family history of bleeding, and being male. Hemophilia A occurs in one out of every ten thousand men. Prevention is somewhat limited. Genetic counseling is available. Having a prenatal intrauterine diagnosis (test of the baby’s blood while inside the uterus of its mother) with termination of pregnancy as an option.
Symptoms of hemophilia are bruising, spontaneous bleeding, nose bleeds, and bleeding into joints. This is associated with pain and swelling. Other symptoms are gastrointestinal tract and urinary tract hemorrhages, and blood in urine and stool. The main symptom is just prolonged bleeding from cuts. This may include tooth extraction and surgery.
Signs and tests for hemophilia are prolonged PTT, normal prothrombin time, normal bleeding time, normal fibrinogen level, and serum factor thirteen and nine antigen.
Treatment for hemophilia is not yet completely underway. Now in the developmental stage, Gene Therapy is designed to replace a hemophilia gene with a healthy one. Healthy factor thirteen and nine genes would be inserted into enough cells to permit a person to produce factor normally. Here is how it works. The healthy genes are put into vectors, which transport them to target cells in the body. The most successful vectors produced have been viruses that neither harm the cells or cause disease. Presently, the results look promising in humans. But much further research is necessary before a viable gene therapy product will be available.
Mild cases of hemophilia can be treated with an infusion of drugs called cryoprecipitate or desmopressin. This causes a release of factor thirteen or nine within the body, on the lining of the blood vessels. Regular prophylactic infusions at home may be prescribed to patients. These may also be necessary given prior to dental extractions and surgery to prevent bleeding. Immunization of Hepatitis B is also a treatment. Hemophiliacs are at risk for hepatitis due to exposure of many blood products. The outcome is usually good with treatment; people can live relatively normal lives.
Hemophilia B is seven times less common that hemophilia A. Type B is the deficiency of plasma protein factor nine that affects clotting. Alternative names for this type of hemophilia are the Christmas disease, and factor nine hemophilia. This type occurs in one out of every fifty thousand men. All other information about hemophilia B is included my other research.
Hemophilia is the oldest know hereditary bleeding disorder. A small percentage of hemophiliacs treated may die from blood loss. Complications that can occur are chronic joint deformities and intracerebral hemorrhages. There are about twenty thousand hemophilia patients in the U.S. today. Four hundred babies are born with it each year. Eighty-five percent have type A, and fifteen percent have type B. Seventy percent of type A hemophiliacs have less than one percent of the normal clotting factor, hence making a severe case. Hopefully with the new Gene Therapy, we can soon say goodbye to this terrible disease.