Haemophilia type A

Haemophilia type A

    * Introduction
    * Clinical signs
    * Diagnosis
    * Treatment
Haemophilia is transmitted X-linked congenital, hereditary nature. The cause of the disease is represented by synthesis or alteration in quality small amount of globulin antihemofilice A or B. The epidemiological 120-130 are found in 100 cases. 000 births.
Haemophilia type A meets a percentage of 80% of Haemophilia syndromes. This type of disease is 4-5 times more common than type B. Haemophilia Pathogenesis of disease is criminalized in a deficit of factor VIII: C VIII clotting activates itself, VIII R - WF (Willebrand), and VIII RA (antigen). These are two essential fractions: high molecular weight and high molecular weight (factor VIII C).
A percentage of 60% of cases familial disease, inherited by heterozygous mothers (XnormalXpatologic) XpatologicY boys expressing homozygous or, in exceptional cases. A percentage of 40% of cases occur after a mutation or illegitimate children with a history or falsified. The value of the complex physiological FVIII-FVW is to increase the synthesis of FVIII, protecting it from proteolysis and it focuses on places of active hemostasis, specifically in the vascular lesions. This occurs through binding factor subendoteliale FVW vascular matrix proteins and platelets. The main role of FVIII in the coagulation process is to accelerate the rate and rhythm splitting FX, so the latter factor is activated by activation of F IX. In this recatii involved in several components, FVIII enzyme with substrate are focused on a phospholipid surface to form a complex with calcium dependent. Separation of FVW FVIII to bind to the phospholipid surface is by enzymatic cleavage of FVIII by thrombin molecule or F Xa.
In terms of pathogenic, FVIII deficiency tromboplastinogeneza endogenous change, disrupts the conversion of prothrombin into thrombin leading to fibrin formation in insufficient quantities. In patients with haemophilia, with the introduction of polymerase chain reaction (PCR) and DNA study of restriction enzymes have made progress in the studies of mutations in genes affecting the F VIII synthesis. It has been shown as a percentage of 50% of the mutations that cause severe hemophilia type A were created by reversing the DNA sequence in intron 22 FVIII gene that causes disjunction. Actualmenete, specific mutations are used to identify the genes direcete antenatal diagnosis and analysis of carriers of haemophilia. Analysis of these mutations may be useful in determining the prediction of the likely development of antibodies inactivated FVIII or IX. There is a heterogeneity of mutations in hemophilia A, in explaining the diversity in clinical severity of the disease and how manifestrae present in patients with hemophilia A. Genetic defects in hemophilia A consist in joint inversions with the chromosomal material pierderae interseaza intron 22. Major defects are found, such as deletions, duplications, translocations found in 3-5% of cases or small defects, such as different mutations responsible for 75% of cases of hemophilia A.