We studied the association between these two polymorphisms and VTE in a hospital-based case–control study. We also assessed whether an independent or interactive association exists between Aα-fibrinogen Thr312Ala and FXIII Val34Leu polymorphisms and VTE. Fibrinogen Aα-Thr312Ala and FXIII Val34Leu polymorphisms were determined after PCR and restriction endonuclease digestion in 286 patients with idiopathic VTE and 286 age- and gender-matched controls. Results were analysed using a conditional logistic regression model for matched series.
The Fg-Aα 312Ala allele was associated with higher risk of VTE (OR 1.5; 95%CI: 1.1 to 2.2, p=0.01) while the FXIII 34Leu allele appeared protective (OR 0.7; 95%CI: 0.6 to 0.9, p=0.02). Both alleles demonstrated an independent association with idiopathic VTE after adjustment for Factor V Leiden and G20210A prothrombin polymorphisms. There was no interaction between the fibrinogen Aα-Thr312Ala and FXIII Val34Leu polymorphisms for the risk of VTE.
In this case-control study, the fibrinogen Fg-Aα 312Ala allele was associated with an increased risk of VTE. The FXIII 34Leu allele was also significantly associated with a lower risk of VTE without any interaction between the two polymorphisms studied.