Hemophilia is a rare genetic disorder that affects the blood's ability to clot properly. Due to this, people with hemophilia may experience excessive bleeding when injured or going through certain daily activities such as sports and exercise. Hemophilia is passed on from parents to children through genes, meaning it can be potentially inherited by a child of either sex if it has been previously diagnosed in family members. Hemophilia A accounts for 70-80% of cases, while hemophilia B accounts for 20-30%. It can occur in males, females, and children. It is caused by a lack of or decreased production of clotting factor VIII/IX or clotting factor II, a short-chain protein that plays a crucial role in the formation of blood clots.
Types of Hemophilia
Hemophilia is categorized into 3 types based on the symptoms of the individual.
- Hemophilia A, also known as classical hemophilia, is caused by a deficiency in clotting factor VIII. This type affects about 80% of all people with hemophilia, making it the most common form of the disorder. It occurs in between 1 in 5,000 and 1 in 10,000 male births and is generally diagnosed within the first few days after birth. (Shahani & Geraldson). Hemophilia A can be mild or severe depending on how much clotting factor VIII an individual has lost.
- Hemophilia B is caused by a deficiency in clotting factor IX. This type affects about 30% of all people with hemophilia, making it less common than type A. It occurs in between 1 in 20,000 and 1 in 10,000 male births and generally is diagnosed within the first few days after birth. (Shahani & Geraldson) Hemophilia B can be mild or severe depending on how much clotting factor IX an individual has lost.
- Hemophilia C is caused by a deficiency in both factors VIII and IX. This type affects only one out of every 5 million people with hemophilia, making it rare. Hemophilia C can be mild or severe depending on how much clotting factor IX an individual has lost.
Recognizing Hemophilia
The first thing a physician will do is take a complete medical history, including questions about any symptoms you've had in the last six months. Often, a person with hemophilia will have bleeding symptoms before they are diagnosed. If a doctor suspects hemophilia then they'll order tests to prove it. If hemophilia is suspected, your blood will be tested and your clotting time(time to clot) recorded. Your doctor will take a blood sample from you, usually from your arm, and add certain chemicals to it. This is called "activating" the blood. The chemicals trigger the release of clotting factors from the white cells in your blood. The blood is then placed into a machine that measures the time it takes for the blood to clot. If your blood has hemophilia, it will take a longer time to clot. Hemophilia can also be detected by studying family members for genetic mutations that cause this disorder.
Treating Hemophilia
There is no cure for hemophilia. The only treatment available is to help reduce the amount of bleeding you may experience. For hemophilia A, a clotting factor (a type of protein) can be given to replace the missing clotting factor in your blood. Clotting time improves in most people within 6 weeks of receiving this treatment. Clotting time may improve faster in some people compared to others. Doctors can treat mild bleeding by injecting a clotting factor just before the person is about to undergo a procedure or activity that could cause bleeding. In emergencies, doctors use intravenous infusions of clotting factors to stop bleeding.
Some therapy has been developed to fix genes and is being used to treat people with severe hemophilia B and hemophilia C. It replaces the defective gene in your body with a normal one. This is done using an engineered virus that is supposed to be harmless (a vector system). These viruses are genetically altered so they cannot reproduce, but they are still able to deliver DNA (genetic code) into human cells. Viruses are also used to deliver clotting factors in hemophilia A patients; however, these viruses can reproduce so there is a small risk of the treatment leading to an infection. This treatment has not been very successful thus far, and a cure for this condition is currently unavailable.