World Hemophilia Day: Hereditary disease still unknown

This World Hemophilia Day is an opportunity to raise awareness of this rare hereditary genetic disease that affects about 7000 people in France and for which there is still no cure.

About 7,000 people in France suffer from hemophilia, a rare hereditary genetic disease that prevents blood from clotting properly. As the Inserm explains, in case of bleeding, the flow can not stop or so, very difficult. "The patients are therefore at risk of severe bleeding in case of injury and sometimes spontaneous bleeding, especially in the joints". Current treatments can "control" the disease, but not cure it. This 29th day of hemophilia is an opportunity to talk about this little-known pathology, often stigmatized and misunderstood.

Two types of hemophilia

For starters, there are two main types of hemophilia: hemophilia A, which is the most common since it affects one baby boy out of 5,000 births. This, without going into detail, is characterized by a deficiency of coagulation factor VIII. Then there is hemophilia B, five times rarer since it concerns a small boy out of 25,000 births, linked in turn to a deficit of factor IX coagulation. The treatments fortunately make it possible to fill the lack of coagulation factors VIII and IX, but must be administered by infusion, repeatedly to prevent the risks, or punctual in case of haemorrhage.

The degree of severity of the disease varies from one patient to another: "it is severe in half of cases, minor in 30 to 40% of patients and moderate in others," says Inserm. However, it is not an evolutionary disease: "whatever its severity, it remains the same throughout life".

Hemophilia in childhood

The majority of patients are male, in particular because hemophilia is transmitted by the X chromosome where the offending genes are located. "Having only one copy of this chromosome, boys are systematically sick when they inherit a mutated gene, whereas girls with two X chromosomes are sick only if they inherit two X chromosomes each carrying a mutated gene.This situation is extremely rare ".

Excessive bleeding during early childhood (which can occur as early as 3 months of age) is an indicator of the disease. When the child begins to move, bruises may appear on his legs, as well as bleeding in the muscles and joints. In some cases, these bleeds even cause hematomas that need to be removed through surgery so that they do not compress other vessels or nerves.

Pain and disability

Complications related to hemophilia can be life-threatening and / or have a significant impact on quality of life. For example, hemarthrosis, that is, effusions of painful blood in the joints, causes swelling and loss of flexibility. In the long term, this can lead to disability. Some hemarthroses can be fatal when they occur in the brain, chest, or abdomen.

Where is the research?

In 2017, two major therapeutic breakthroughs in hemophilia A were presented at the American Congress of Hematology, ASH. One concerns a bispecific antibody tested subcutaneously in 60 children with hemophilia A, which mimics the role of factor VIII, the missing coagulation factor. The other concerns a gene therapy in a preliminary study conducted on 13 adults, but which gives hope for a cure for the patients who will benefit.

In May, researchers affiliated with the Salk Institute for Biological Studies in California demonstrated in mice that hemophilia B could be treated for life with a single injection, but further research is needed before testing. clinical on humans.

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