Haemophilia, also known as other translations including: hémophilie, hemofilie, hemofili, hemofilia, hämophilie, emofilia, is a rare blood disorder caused by an inherited gene that results in the blood does not clot properly.
People with haemophilia lack one of the essential blood clotting factors. It is mainly a male disorder because the haemophilia gene is carried on the X chromosome. However it can occur in any family. People with haemophilia need special first aid for injured muscles or joints.
There are two main types of hemophilia – Hemophilia A (due to factor VIII deficiency) and Hemophilia B (due to factor IX deficiency). They are clinically almost identical and are associated with spontaneous bleeding into joints and muscles and internal or external bleeding after injury or surgery.
A very rare type of Hemophilia is Acquired hemophilia. The patient develops the condition during his/her lifetime and it does not have a genetic or heritable cause. It occurs when the body forms antibodies that attack one or more blood clotting factors, (usually factor VIII), thus preventing the blood clotting mechanism from working properly. Patients may be male or female and the pattern of bleeding is rather different from that of classical hemophilia, the joints being rarely affected. The disorder is particularly associated with old age and occasionally complicates pregnancy.
What causes Hemophilia?
Haemophilia is an X-linked recessive disorder. Women have two X chromosomes while men have one X and one Y chromosome. This means that most people with the condition are male- if a woman inherits the abnormal gene from her mother she will still have a normal X chromosome from her father but a man has only one X chromosome so if it contains the faulty gene there is no normal chromosome to counter it.
Women who carry the faulty gene on one of their two X chromosomes will still be carriers and can pass the disease on to their children. Occasionally, a woman inherits two faulty X chromosomes from her parents, in which case she will have haemophilia.
Although it’s inherited, in around one in three cases of haemophilia there’s no family history of the disease, and it may take longer for the problem to be identified.
Prenatal testing – if a pregnant woman has a history of hemophilia, a hemophilia gene test can be done during pregnancy. A sample of placenta is removed from the uterus and tested. This test is known as a CVS (chorionic villus sampling) test.
Blood test – if a doctor suspects a child may have hemophilia a blood test can determine whether the patient has hemophilia A or B, and how severe it is. Blood tests can be performed from the time of birth onwards.
There’s no cure for haemophilia and, although patients are treated with injections of the missing clotting factor, there’s no permanent way of increasing its level.
So the principal of treatment is supplement of the missing clotting factor. This is known as replacement therapy and these days, in most countries including the UK, it usually consists of injections of concentrates of artificially produced clotting factors (made using recombinant technology, rather the old method of extracting the clotting factors from donated blood).
In severe haemophilia injections may be given on a regular basis several times a week. This is called prophylaxis, and it aims to help keep bleeding from happening. In mild or moderate haemophilia injections are given just when a bleed has or may have occurred (this is called on-demand therapy).
If a person known to have haemophilia has a bleed, immediate measures – such as resting quietly and splinting the joint or limb – will reduce the amount of blood lost, but they need specialist management, including treatment with factor VIII or IX concentrate.
People with the condition will often keep a supply of clotting factor in the fridge at home. They should also known where their nearest appropriate treatment centre is, as this may not be at their local hospital.
If someone you know is a haemophiliac, it’s worth checking with them about what they need and where their local supply and treatment centres are in case of emergency.
In the past there have been very serious problems with blood products contaminated with infections such as HIV and Hepatitis, which have resulted in fatal infections in people with haemophilia. With the introduction of recombinant factors, the risks from donated blood , have mostly been resolved. Concern still remains about possible vCJD infection from past treatments using blood products, but most well-managed haemophiliacs should expect to enjoy a lifestyle and longevity similar to that of their peers.
Another medication, known as desmopressin, may also be used in some instances to try to raise the body’s own levels of the missing clotting factors, especially before planned surgery or dentistry.