OBJECTIVETo analyze the frequency of beta-fibrinogen (beta-Fg) gene -455G/A, -148C/T and 448G/A polymorphism, fibrinogen molecular reactivity and their association with plasma fibrinogen levels in health adults, myocardial infarction and cerebral infarction disease.

METHODSThe beta-Fg gene -455G/A, -148C/T and 448G/A polymorphisms were analyzed by restriction fragment length polymorphism (RFLP). Fibrinogen molecular reactivity was analyzed for the conversion kinetics of fibrinogen into fibrin by a computer assistant procedure. Plasma fibrinogen levels were determined by Clauss method.

RESULTSThe frequencies of -455A, -148T, 448A allele in health adults were 0.185, 0.194 and 0.192, in myocardial infarction disease 0.295, 0.318 and 0.307, in cerebral infarction disease 0.177, 0.193 and 0.182, respectively. The frequencies of -455A, -148T, 448A alleles in myocardial infarction disease were apparently higher than that of health adults. There were close linkage between -455G, -148C and 448G or -455A, -148T and 448A, the correspondence was over 98%. There are no differences in the plasma fibrinogen levels of the three polymorphisms in two genotype groups. The fibrinogen molecular reactivity was significantly increased in cardiocerebral vascular disease and related with plasma fibrinogen level.

CONCLUSIONThe three polymorphisms loci are strong linkage disequilibrium. There are no significant differences in the plasma fibrinogen levels of the three polymorphisms in two genotype groups. The frequencies of -455A, -148T, 448A alleles in myocardial infarction disease were apparently higher than that of health adults. It suggest that there was no association between beta-Fg gene -455G/A, -148C/T and 448G/A polymorphisms and plasma fibrinogen levels, but did in myocardial infarction disease. The fibrinogen molecular reactivity was significantly increased in cardiocerebral vascular disease and related with plasma fibrinogen level.