The Study Of β-fibrinogen Gene-455G/A,-148C/T Polymorphisms In Patients With Cerebral Infarction

Objective: (1) to investigate the frequencies of beta-fibrinogen (Fg-j3 ) gene -455G/A and -148C/T polymorphisms in patients with cerebral infarction and health adults. (2) to investigate the relationship between the frequency of Fgβ -455G/A polymorphism and that of Fgβ -148C/T polymorphism. (3) to investigate the relationship between the Fgβ -455G/A ,-148C/T polymorphism frequency and plasma fibrinogen levels. (4) to explore the contribution of Fgβ -455G/A and -148C/T polymorphism to cerebral infarction and to carotid arteriosclerosis .Methods: ninety patients with cerebral infarction and one hundred and two health adults were included in this study. Carotid was assessed using carotid Doppler ultrasongraphy in all patients with cerebral infarction, and consequently cerebral infarction (CI) group was divided into two subgroups: CI with carotid plaque and CI without carotid plaque. Having been sifted with carotid Doppler ultrasongraphy, all health adults in control group were free of carotid plaque. The Fgβ -455G/A and -148C/T polymorphisms were analyzed by restriction fragment length polymorphism(RFLP).Plasma fibrinogen levels were determined by Clauss method.Results: (1) In CI group, CI with carotid plaque group, CI without carotid plaque group and control group, the plasma fibrinogen levels were 3.55 + 0.94, 3.61 + 0.96, 3.44 + 0.82 and2.67 + 0.78 g/1 respectively. The plasma fibrinogen levels in CI group and its subgroup were significantly higher than that of health control group (P<0.01) . (2) The frequencies of -455A, -148T allele were 0.186 and 0.206 in healthcontrols, 0.289 and 0.306 in CI patients, 0.345 and 0.362 in CI patients with carotid plaque, 0.188 and 0.203 in CI patients without carotid plaque,respectively. The frequencies of -455A, -148T alleles in CI patients with carotid plaque were higher than that of in health controls(p<0.05). (3)There was close linkage between -455G and -148C or between -455A and -148T, and the correspondence was over 96%. (4)In both control group and CI group, the plasma fibrinogen levels of those with -455A allele were higher than that of those without -455A allele,3.44+0.67 versus 2.32+0.77 (P<0.01) and 3.80 + 0.64 versus 3.31 + 0.97 (p<0.05) respectively; and the plasma fibrinogen levels of those with -148T allele were higher than that of those without -148T allele, 3.29 + 0.66 versus 2.33 + 0.77 (P<0.01) and 3.77 + 0.65 versus 3.31 + 0.97 (P<0.01) respectively. In CI with carotid plaque group ,the plasma fibrinogen level of those with -455A allele was higher than that of those without -455A allele ,3.84 + 0.78 versus 3.29 + 0.90(P<0.05),and the plasma fibrinogen level of those with -148T allele was higher than that of those without -148T allele ,3.83 + 0.68 versus 3.27 + 0.89 (P<0.01) .In CI without carotid plaque group , Fgβ-455G/A and -148C/T polymorphisms were not correlated to the plasma fibrinogen level.Conclusion: (1)there is strong linkage disequilibrium between the two polymorphism loci;(2)The alleles of-455A and -148T are associated with the susceptibility to cerebral infarction with carotid plaque;(3)In control group , CI group and CI with carotid group, the Fgβ -455G/A and -148C/T polymorphisms are correlated to the plasma fibrinogen level.