[beta-fibrinogen gene -455A/G polymorphism and plasma fibrinogen level in Chinese stroke patients]

To explore the relationship between beta-fibrinogen gene -455A/G polymorphism and plasma fibrinogen level and to determine the influence of the mutation on ischaemic stroke.

Ninety-one patients (63.5 +/- 10.1 years) with ischaemic stroke, 74 control patients (60.6 +/- 10.8 years) without any thromboembolic events and 98 healthy blood donors (37.5 +/- 13.3 years) were enrolled in this trial. beta-fibrinogen gene -455A/G polymorphism was analyzed from all subjects by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) with restrictive enzyme Hae III. Plasma fibrinogen levels were obtained from prothrombin time (PT) assay. The parameters were compared between any two different groups by unpaired t-test and Chi-square test. Before the analysis, log transformation was carried out for concentrations of fibrinogen.

Frequency of H2 allele was higher in male patients with ischaemic stroke than in control patients (22.7% vs 7.1%, chi(2) = 5.56, P < 0.02). There was no significant difference in female patients. In the subjects without any thromboembolic events (including control patients and healthy blood donors), frequency of H2 decreased with age (>/= 40, 21.3%; 41 approximately 59, 15.4%; >/= 60, 10.0%). Among male control patients and healthy blood donors, the level of plasma fibrinogen was lower in the H1H1 genotype (287 g/L +/- 96 g/L and 234 g/L +/- 58 g/L) than in H1H2 and H2H2 genotypes (331 g/L +/- 44 g/L and 307 g/L +/- 55 g/L; t = 2.53 and 9.67, P < 0.05); among females, this tendency was not found.

Plasma fibrinogen expression is affected by the beta-fibrinogen gene - 455A/G polymorphism. H2 allele is a risk factor for ischaemic stroke in Chinese men.