In Haemophilia A, protein called factor VIII coagulant is missing (FVIII: C), the gene for this protein is present on the X chromosome, his legacy is so diaginica, can be transmitted from carrier mother to her son.

Typically, only males are affected by the disease because they have only one X chromosome, while women are healthy carriers, unless daughters of haemophiliac father and a healthy carrier mother.

The severity of the disease depends on the amount of FVIII: C present and based on this factor we can distinguish three levels of disease severity: mild, intermediate and moderate.

The best known form of haemophilia is linked to a defect in synthesis of factor VIII (in particular of its subunit C, protein component to pro-coagulant activity otherwise known as globulin or anti-haemophilic factor.

The lack of the other subunits, known as R or Von Willebrand factor, is instead responsible (homonym disease) of blood clotting. It affects only males, mode of transmission is sex-linked hereditary chromosome X (containing the gene responsible for synthesis of factor VIII), the typical mode of transmission of haemophilia A is from carrier mother to male child.

If an affected male has children, no male child will be affected, while all the daughters will be carriers.

The occurrence of haemophilia A is not always predictable based on the rules of the transmission of hereditary characteristics: in 30% of cases the disease is the result of a spontaneous mutation of a maternal X chromosome.

Haemophilia A is a relatively rare disease: one case per 10000 people. The clinical picture is dominated by spontaneous haemorrhages. Characteristic is the fact that the bleeding can happen after a trauma.

Deficiency of factor VIII-C causes, in fact, a minor alteration in haemostasis, with reduced or absent formation of fibrin clot at the haemostatic plug. Immediately after the vascular injury, haemostasis seems normal because you have altered platelet and haemostatic plug is formed regularly, the bleeding appears to the relative distance from the trauma and may recur after hours or days for secondary haemostasis impairment.

Particularly serious are the intra-articular bleeding (haemarthrosis) at the knee, hip, shoulder, elbow, which can cause permanent joint stiffness (ankylosis). The most feared complication of haemophilia A is represented by cerebral haemorrhage.

The diagnostic suspicion must be confirmed by performing a series of tests, including tests of haemostasis and platelet count, bleeding time, PT and PTT: typically, in these patients is observed only the lengthening of PTT, while other tests are normal. It is also possible a specific dosage of individual coagulation factors, including factor VIII.

The treatment is based primarily on the use of concentrated preparations of factor VIII in lyophilized powder, obtained from mixtures of many donors. The selection of donors, combined with more selective purification processes, has helped to reduce drastically the risk of infection by viral hepatitis and AIDS transmitted by transfusion of blood products.

Caution should be observed in subjecting patients to major and minor surgery (including dental maneuvers).

Haemophilia B is a disease of genetic transmission and an identical severity of haemophilia A, but this type of haemophilia is characterized by a lack of factor IX (FIX:C).

Similarly to haemophilia A is a hereditary disease linked to chromosome X and affects 1 in 100000 newborn males.

The clinical picture is similar to the form of factor VIII deficiency.

Again, therapy is based on the transfusion of factor IX missing, either through fresh frozen plasma transfusion and plasma fractions enriched in pro thrombin.

Warning: possible thrombosis events can complicate the treatment to which it is therefore appropriate to associate a concomitant heparin anticoagulation.

Haemophilia C is a rare and milder form of hemophilia.

The deficient protein is factor XI (FXI), the gene that synthesizes this protein is present on an autosomal chromosome or one chromosome sex-linked, then we will find both male and female patients.

Treatment of haemophilia is based on replacement therapy and essentially consists in the administration of an adequate amount of the deficient protein, and is only done in the presence of haemorrhage, or to prepare the patient for surgery, or even in the case of tooth extraction.

It's an effective therapy that allows the patient to lead a normal life.

There are two complications in this type of therapy: the first is the possible development of substances that inhibit the function of the protein, making the therapy administered ineffective; The second complication is the possibility of infection because the drug administered is a blood product.

In the 80's a high number of haemophiliacs undergoing treatment developed hepatitis B infection.

Today the chance of infection is rare because the blood products currently available on the market are prepared with special techniques that ensure against the risk of infection.

Von Willebrand's Disease is the most common hereditary bleeding disorder and is transmitted in an autosomal dominant (less often recessive).

Gene mutation in the chromosome 12 causes a lack of quantitative or qualitative VWF.

Spontaneous bleeding events (menometrorragie, epistaxis) or small lesions induced by traumatic tooth extraction, tonsillectomy, etc...

The type III (recessive) is the most severe and very severe haemorrhagic symptoms.