Hemophilia is a constitutional anomaly of blood clotting in connection with a deficit of one of the clotting factors. These flaws are due to a deficiency of one of the following factors: XII, XI, VIII and IX, or the presence of anticoagulants against any of these factors.
The clinical manifestations of the disease are commensurate with the deficit of clotting factor. The clinical manifestations are bleeding that can reach every body, particularly the joints (haemarthroses) and muscles (bruises). The disease can be severe with events in the first year of life or mild with very few events.
There are several types of hemophilia-related coagulation factors deficit:
* Hemophilia A (classic hemophilia) is a mutation of factor VIII
* Hemophilia B (or Christmas disease) is a mutation of factor IX
* Hemophilia C (or Rosenthal's Disease) is a mutation of Factor XI.
Mutation F8 locus q28 of the X chromosome encoding coagulation factor VIII. This mutation is often an inversion of the intron 22 or deletions and insertions.
The incidence of this disease is 1 in 4 000 births of boys with a prevalence of 1 in 10 000 in countries with high sanitation.
It can be confused with Willebrand disease because it also presents a decrease of factor VIII.
Mutation F9 locus q27 X chromosome encoding coagulation factor IX.
There are over 2100 mutations that can cover this gene The incidence of this disease is 1 in 20 000 births of boys with a prevalence of 1 in 25 000 in countries with high sanitation.
It is a mild form of hemophilia unrelated to sex. It does not require most often no cure.
It reaches one in 100,000.
The blood of a person with hemophilia does not clot normally. Bleeding is not more abundant, or faster than normal, but last longer. Many people believe that hemophiliacs bleed much to the slightest break. The superficial wounds are usually not serious, they do not bleed more than a non hemophiliac otherwise a simple tape to stop the bleeding.
The internal bleeding, for against, have more serious consequences, particularly if they involve the joints, especially knees, ankles and elbows, and the soft tissues and muscles.
The severity of hemophilia is based on the percentage of activity of coagulation factor deficit. Normal activity is between 50 and 150%.
between 5 and 30% of activity of coagulation factor.
* Can not present bleeding disorder
* No bleeding less than an injury
* Risk of prolonged bleeding after surgery or serious injury
* Bleeding rare.
between 1 and 5% of activity of coagulation factor.
* Risk of prolonged bleeding after surgery, serious injury or dental surgery.
* Can present episodes of bleeding about once a month.
* Saigne rarely, if ever without obvious reason.
less than 1% of activity of coagulation factor.
* Bleeding frequent in muscles or joints (mainly knees, elbows and ankles).
* Can present episodes of bleeding once or twice a week.
* May bleed without obvious reason.
Based on tests performed in the current exploration base hemostasis:
* The time of hemoglobin is increased
* Determination of coagulation factors VIII, IX and XI
* Contrary to popular belief bleeding time is usually normal
* Prothrombin time and rate of platelets are normal
Transmission of the disease
The hemophilia A and B are related to the recessive X chromosome but a third of hemophiliacs correspond to a de novo mutation.
There is therefore a man who bears the Xh is still affected by the disease while the woman is that Carrier (but may pass it on to their descendants). This should be considered for genetic counseling.
Rare cases of women hemophiliacs (Xh / Xh) were listed. These could include women from the union of a hemophiliac father (Xh Y) and a surrogate mother (X Xh), but the likelihood of such a descent remains low. Cases have also been identified where the woman does only one hit X (X Xh) and manifest, however, a severe hemophilia, this is due to a severe X inactivation healthy (X) . In addition, carriers may also have symptoms more or less severe. They are called "low-rate carriers."
Current treatments do not cure of hemophilia, but they consist of intravenous administration of Factor VIII or Factor IX for obtaining a clotting activity sufficient to stop or prevent bleeding.
Current treatments are either from the plasma (blood plasma products, eg Factane, Betafact) or synthetic products derived from biotechnology (recombinant products), which partly (eg Kogenate, Helixate, ReFacto) or completely (eg Advate, Benefix) eliminated the traces of blood in their manufacturing processes and in the final product.
History of the disease
It is a disease known for millennia. The ancient Hebrews of knew already and do not practice circumcision of boys whose mother came from a family who lost a child by hemorrhage during a circumcision.
The genealogy of Queen Victoria of the United Kingdom is known to wear it hemophilia. Leopold, one of its four son, born with hemophilia and died at the age of 31 years of brain haemorrhage. Two of the five daughters of Queen Victoria, Alice and Beatrice, carry forward and this will eventually be called the "royal disease" in the royal families of Europe and Russia. The most famous descendant hemophilia is Alexis, son of the last Russian Tsar Nicolas II. These facts have been questioned in 2004 by Kendrick in an article in the American Journal of Hematology.
The AIDS epidemic has been particularly deadly for hemophiliacs. These, in need of regular transfusions, many of contracting the virus. In France, this has resulted in a major political scandal, the case of tainted blood.
Read also Blood Transfusion