Hemophilia is a genetic hemorrhagic disease that prevents blood from clotting, causing unusually long bleeding when injured and sometimes without injury. It is caused by a genetic mutation that causes the lack or absence of clotting proteins that prevent a clot from forming strong enough to stop the bleeding.

Hemophilia is considered a disease of boys and affects 1 in 5000 births of boys. However, girls can carry the genetic mutation and develop a minor form of the disease. In the total population, 1 in 12 people have hemophilia. (000) There are two predominant types of the disease: hemophilia A and B. The prevalence of hemophilia A is higher than that of hemophilia B (1/1 males against 6 / 000) . (1).

Hemophilia was still a very debilitating and fatal disease a few decades ago from childhood and adolescence. Today, effective but restrictive treatments make it possible to curb bleeding and limit bodily harm and disabilities in people with hemophilia.

the child. Prolonged bleeding occurs following an injury or even a minor trauma. They can be spontaneous (therefore intervene in the absence of trauma) in severe forms of the disease. Bleeding can be internal or external. Note that bleeding in a person with hemophilia is not more intense, but that its duration is longer. Bleeding in the muscles (bruises) and in the joints (hemarthrosis), mainly in the ankles, knees and hips, can over time cause stiffness and disabling deformities, which can lead to paralysis.

The disease is all the more severe when the amount of coagulation factors in the blood is low (1):

• Severe form: spontaneous and frequent haemorrhages (50% of cases);
• Moderate form: abnormally long haemorrhages following minor injuries and rare spontaneous haemorrhages (10 to 20% of cases);
• Minor form: abnormally long haemorrhages but absence of spontaneous haemorrhages (30 to 40% of cases).

The blood contains proteins, called clotting factors, which allow a blood clot to form and therefore stop bleeding. Genetic mutations prevent the production of these proteins. If the symptoms associated with hemophilia A and B are very similar, these two types of the disease nevertheless have a different genetic origin: hemophilia A is caused by mutations in the F8 gene (Xq28) encoding the coagulation factor VIII and l hemophilia B by mutations in the F9 gene (Xq27) encoding the coagulation factor IX.

Hemophilia is caused by genes located on the X chromosome. It is a genetic disease known as “X-linked recessive inheritance”. This implies that a sick man will pass the altered gene only to his daughters, who can pass it, with a 50% risk, to their daughters and boys. As a result, the disease almost exclusively affects men, but women are carriers. About 70% of hemophilia have a family history. (1) (3)

Treatments now make it possible to prevent and curb bleeding. They consist of intravenously administering an antihemophilic factor: factor VIII for hemophiliacs A and factor IX for hemophiliacs B. These antihemophilic drugs are produced from products derived from blood (of plasma origin), or manufactured by engineering. genetics (recombinants). They are administered by regular and systematic injections to prevent bleeding, or following a bleeding event. Physiotherapy allows people with hemophilia to maintain the flexibility of muscles and the mobility of joints that have suffered repeated bleeding.