Hemophilia a

August 12, 2017 17:51 | Genetic Diseases

This disease is the most frequent clotting disorder resulting from factor VIII clotting deficiency.In total there are XV clotting factors.All of them are located in the blood plasma.Hemophilia A is the only one among all the blood-clotting disorders diseases with a recessive form, adhered to the X-linked inheritance.

located on the X chromosome gene of hemophilia is passed from a man with hemophilia, all of his daughters, in connection with which they will inevitably become the transferors of the disease.At the same time all the sons of men patient remain healthy, as derive their sole X-chromosome from a healthy mother.Women who are carriers of one X chromosome with the mutant gene of hemophilia, half the sons have a chance to be born sick (because there is an equal probability to receive mother-mutated or normal X chromosome), and half of the daughters have the chance to become the transferors of the disease.This rule is consistently confirmed only in a large population, but not in some families where

all the children can sometimes suffer from hemophilia or, on the contrary, are born only healthy boys.

Women who are carriers of a mutated gene, bleeding is usually not affected since the second normal X chromosome ensures the formation of 1 / 4-1 / 2 parts necessary for normal blood clotting factor VIII, which in most cases is sufficient.However, the rate of factor VIII content can vary within a wide range (60 to 250%).In this regard, some transferors of factor VIII levels in plasma can be as little as 11-20%, threatening bleeding in trauma, surgery and childbirth.

severity of bleeding events (hemorrhage syndrome) in hemophilia is strictly correlated with the degree of deficiency of factor VIII in plasma, which is the level of individual families with hemophilia strictly genetically programmed.A clear dependence of the frequency and severity of bleeding factor deficiency in the blood plasma is violated in the case of heavy blood loss as a result of injuries and operations.