What Is Hemophilia?

Hemophilia is a disease that prevents blood from clotting properly, so a person who has it bleeds more than someone without hemophilia does. It's a genetic disorder, which means it's the result of a change in genes that was either inherited (passed on from parent to child) or occurred during development in the womb. "Hemo" means blood and "philia" means a tendency toward. A person who has hemophilia has a tendency to bleed excessively. Hemophilia affects mostly boys, although it's very rare: Only about 1 in every 5,000 boys is born with it. The disease can affect people of any race or nationality.
When most people get a cut, the body naturally protects itself. Sticky cells in the blood called platelets go to where the bleeding is and plug up the hole. This is the first step in the clotting process. When the platelets plug the hole, they release chemicals that attract more sticky platelets and also activate various proteins in the blood known as clotting factors. These proteins mix with the platelets to form fibers, and these fibers make the clot stronger and stop the bleeding.
Our bodies have 12 clotting factors that work together in this process (numbered using Roman numerals from I through XII). Having too little of factors VIII (8) and IX (9) is what causes hemophilia. A person with hemophilia will only lack one factor, either factor VIII or factor IX, but not both.
There are two major kinds of hemophilia. About 80% of cases are hemophilia A, which is a factor VIII deficiency. Hemophilia B is when factor IX is lacking.
Hemophilia is classified as mild, moderate, or severe, based on the amount of the clotting factor in the person's blood. If someone produces only 1% or less of the affected factor, the case is called severe. Someone that produces 2% to 5% has a moderate case, and someone that produces 6% to 50% of the affected factor level is considered to have a mild case of hemophilia. In general, a person with milder hemophilia may only bleed excessively once in a while, whereas severe hemophilia puts someone at risk for having bleeding problems much more often.
Most people with hemophilia discover they have the condition when they are babies or young kids. Sometimes the disease is so mild that a guy doesn't even know he has it until he has minor surgery — like getting his tonsils or appendix out — and it's found in blood tests that doctors perform before surgery.

 Sign And Symptoms


Signs and symptoms of hemophilia vary depending on how deficient you are in clot-forming proteins called clotting factors. If levels of your deficient clotting factor are very low, you may experience spontaneous bleeding. If levels of your deficient clotting factor are slightly to moderately low, you may bleed only after surgery or trauma.
Symptoms of spontaneous bleeding may include:

• Many large or deep bruises
• Joint pain and swelling caused by internal bleeding
• Unexplained bleeding or bruising
• Blood in your urine or stool
• Prolonged bleeding from cuts or injuries, or after surgery or tooth extraction
• Nosebleeds with no obvious cause
• Tightness in your joints

Emergency signs and symptoms of hemophilia may include:

• Sudden pain, swelling, and warmth of large joints, such as knees, elbows, hips and shoulders, and of the muscles of your arms and legs
• Bleeding from an injury, especially if you have a severe form of hemophilia
• Painful, lasting headache
• Repeated vomiting
• Extreme fatigue
• Neck pain
• Double vision

Babies with hemophilia
At first, because of limited mobility, a baby with hemophilia usually won't have many problems related to hemophilia. But as your baby begins to move around, falling and bumping into things, superficial bruises may occur. This bleeding into soft tissue may become more frequent the more active your child becomes.

Causes

What causes hemophilia?

As mentioned above, hemophilia is caused by a genetic mutation. The mutations involve genes that code for proteins that are essential in the blood clotting process. The bleeding symptoms arise because blood clotting is impaired.
The process of blood clotting involves a series of complex mechanisms, usually involving 13 different proteins classically termed I through XIII and written with Roman numerals. If the lining of the blood vessels becomes damaged, platelets are recruited to the injured area to form an initial plug. These activated platelets release chemicals that start the clotting cascade, activating a series of 13 proteins known as clotting factors. Ultimately, fibrin is formed, the protein that crosslinks with itself to form a mesh that makes up the final blood clot. The protein involved with hemophilia A is factor VIII (factor 8) and with hemophilia B is factor IX (factor 9).
Hemophilia A is caused by a mutation in the gene for factor VIII, so there is deficiency of this clotting factor. Hemophilia B (also called Christmas disease) results from a deficiency of factor IX due to a mutation in the corresponding gene.
A condition referred to as hemophilia C involves a deficiency of clotting factor XI. This condition is much rarer than hemophilia A and B and typically leads to mild symptoms. It is also not inherited in an X-linked manner and affects persons of both sexes.
Hemophilia A is more common than hemophilia B. About 80% of people with hemophilia have hemophilia A. Hemophilia B occurs in about 1 out of every 25,000 to 30,000 people. A subgroup of those with hemophilia B has the so-called Leyden phenotype, which is characterized by a severe hemophilia in childhood that improves at puberty.

Tests and Investigation

For people with a family history of hemophilia, it's possible to test the fetus during pregnancy to determine if it is affected by the disease.
Analysis of a blood sample from either a child or an adult can show a deficiency of a clotting factor. Sometimes, mild hemophilia isn't diagnosed until after a person has undergone surgery and excessive bleeding results.

Treatments and Pharmacology

While there's no cure for hemophilia, most people with the disease can lead fairly normal lives.
Hemophilia treatment varies depending on the severity of the condition:

• Mild hemophilia A. Treatment may involve slow injection of the hormone desmopressin (DDAVP) into a vein to stimulate a release of more clotting factor to stop the bleeding. Occasionally, desmopressin is given as a nasal medication.
• Moderate to severe hemophilia A or hemophilia B. Bleeding may stop only after an infusion of clotting factor derived from donated human blood or from genetically engineered products called recombinant clotting factors. Repeated infusions may be needed if the internal bleeding is serious.
• Hemophilia C. Plasma infusions are needed to stop bleeding episodes.

Regular, preventive infusions of a clotting factor two or three times a week may help prevent bleeding. This approach may reduce time spent in the hospital and away from home, work or school, and limit side effects such as damage to joints. Your doctor or child's doctor can train you to perform infusions of desmopressin or of the clotting factor at home, work or school.
If internal bleeding has damaged joints, physical therapy can help them function better. Therapy can preserve their mobility and help prevent frozen or badly deformed joints. In cases where repeated bouts of internal bleeding has damaged or destroyed joints, an artificial joint may be needed.
For minor cuts
If you or your child experiences a small cut or scrape, using pressure and a bandage will generally take care of the wound. For small areas of bleeding beneath the skin, use an ice pack.


Can hemophilia be prevented?
Hemophilia is a genetic (inherited) disease and cannot be prevented. Genetic counseling, identification of carriers through molecular genetic testing, and prenatal diagnosis are available to help individuals understand their risk of having a child with hemophilia.