Thursday, June 23, 2011

Haemophilia type A

Haemophilia is transmitted X-linked congenital disease, the hereditary nature.The disease is represented by synthesis or alteration in quality small amount of globulin antihemofilice A or B. In terms of epidemiological cases are found 120-130 to 100. 000 births.
Haemophilia type A meets a percentage of 80% of Hemophilia syndromes. This disease is 4-5 times more common than haemophilia type B.The etiopathogenesis of the disease is criminalized a deficit of factor VIII: C VIII clotting properly working, VIII R - WF (Willebrand) and VIII RA (antigen). These are two essential fractions: high molecular weight and high molecular weight (factor VIII C).
A 60% of cases familial disease, inherited by heterozygous mothers (XnormalXpatologic) expressing the boys XpatologicY or homozygous exceptionally.A 40% of cases resulting from a mutation or illegitimate children with a history or falsified.Physiological value of F VIII-complex is to increase synthesis FVW F VIII protecting it from proteolysis and it focuses on places of active hemostasis, specifically in the vascular lesions. This occurs by binding factor protein FVW subendoteliale vascular and platelet matrix.The main role of F VIII in the coagulation process is to accelerate the rate and rhythm splitting FX, so the latter is activated by activating factor IX F. In this recatii in involved several components, the enzyme substrate with F VIII are concentrated on a phospholipid surface to form a complex with calcium dependent.Separation FVW F VIII to bind to phospholipid surface is through cleavage enzyme thrombin molecule by F VIII or F X.
In terms of pathogenic, F VIII deficiency tromboplastinogeneza endogenous change, disrupts the conversion of prothrombin to thrombin leading to fibrin formation in insufficient quantities.In patients with haemophilia, with the introduction of polymerase chain reaction (PCR) and DNA study with restriction enzymes have made progress in terms of studying mutations in genes affecting the F VIII synthesis. Demonstrated a 50% of the mutations that cause severe hemophilia type A were born by reversing DNA sequence in intron 22 that causes disjunction F VIII gene.Actualmenete, specific mutations are used to identify genes for diagnosis direcete antenatal and analysis of haemophilia carriers.Analysis of these mutations may be useful in establishing the likely development of antibodies prediction inactivated F VIII or IX. There is a heterogeneity in haemophilia A mutation, thus explaining the diversity in clinical severity of the disease and how manifestrae present in patients with hemophilia A.Genetic defects in hemophilia A inversion consist in common with the material pierderae chromosome interested in 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 haemophilia A.

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