The Researches On The Phenotypes And The Pathological Mechanisms Of Congenital Afibrinogenemia

Human fibrinogen(Fg), namely coagulation factor I, is not only with the highest protein level in all plasma proteins, but the central protein of coagulation system. The final stage of the coagulation pathway is the formation of thrombin, in which the fibrinogen is transformed into fibrin. In addition to direct participation into coagulation procedure, fibrinogen can mediate the platelet aggregation, consequently has an influence on blood viscosity, and is the great risk factor of cardial-brain vascular diseases. The defects of fibrinogen gene can contribute to congenital afibrinogenemia(or hypofibrinogenemia), and dysfibrinogenemia.The fibrinogen locus comprises three genes coding for fibrinogen gamma (FGG), alpha (FGA), and beta (FGB), clustered in a region of ～50 kb on chromosome 4q28-q31. The gene defect of every one of three fibrinogen genes can lead to the abnormality of fibrinogen protein level or its function. Congenital afibrinogenemia (Mendelian Inheritance in Man No. 202400) was originally described in 1920, and to date about 150 families with this disorder have been described in the literatures. As is commonly the case with rare autosomal recessive disorders, ～50% of cases are associated with consanguinity.Objectives (1)to study the phenotype, perform family survey and clinical diagnosis for one congenital afibrinogenemia patient and his family; (2)to perform fibrinogen genes sequence assay for one congenital afibrinogenemia patient and his family, then find the causative mutation and heredity regularity, finally do some primary researches...