OBJECTIVETo identify the relationship between coagulation factor V (FV) gene single nucleotide polymorphisms (SNPs) and venous thromboembolism (VTE).

METHODSThe FV clotting activity (FV: C) and FV antigen (FV: Ag) in plasma of VTE group (111 patients) and normal control (110 patients) were detected using one-stage clotting assay and ELISA, respectively. Five pairs of primers of the F V polymorphisms including Asp79His, Arg306The, Arg306Gly, Arg506Gln and Ile359The/His1299 Arg were synthesized and amplified by PCR. The PCR products were digested by restriction enzyme using PCR-RFLP. The detected polymorphisms were confirmed by direct sequencing. The samples containing the polymorphisms were screened for coding regions of all F V exons with direct sequencing.

RESULTSThe plasma levels of F V: C and F V: Ag of VTE group and normal control were (106.9 +/- 28.0)%, (110.4 +/- 33.3)% and (102.4 +/- 30.9)%, (102.1 +/- 24.1)%, respectively. The plasma level of FV: Ag was significantly different between VTE group and normal control. However, there was no difference in F V: C levels. Polymorphisms for the fore mentioned 5 primer pairs were not found in either patients or normal controls. Polymorphism of His1299Arg was identified in 5 patients with VTE and 3 normal controls. And these 5 cases also combined Met1736Val polymorphism, 3 of them combined another Asp2194Gly polymorphism.

CONCLUSIONThe higher plasma level of F V: Ag contribute to venous thromboembolism. There is no relationship between polymorphisms of Asp79His, Arg306The, Arg306Gly, Arg506Gln, Ile359The and venous thromboembolism in Chinese studied. Polymorphism His1299Arg is higher in VTE group than in normal control, but has no statistical difference. Polymorphisms of His1299Arg, Met1736Val and Asp2194Gly are linked disequilibrium in Chinese Han population.