The 3'end prothrombin gene variants in patients with different thrombotic events

Background: Prothrombin (FII) A19911G and C20221T gene variants are associated with increased prothrombin levels and potentially represent thrombotic risk factors.

Objective: To determine the frequency of A19911G and C20221T FII gene variants in patients with thrombotic disorders and in women who have experienced pregnancy loss (PL).

Methods: We determined the frequency of these variants in 133 patients with deep venous thrombosis (DVT), 80 patients with isolated pulmonary embolism (PE), 101 patients with idiopathic PL, and 180 control individuals.

Results: The FII A19911G variant was more prevalent in patients with DVT and with PL compared with controls; however, these differences were not statistically significant. The 19911GG genotype was associated with increased risk of PE (odds ratio, 1.91; 95% confidence interval, 1.04-3.51). We did not detect carriers of the FII C20221T gene variant in this study.

Conclusions: This is the first study, to our knowledge, that demonstrates the FII 19911GG genotype may represent a risk factor for isolated PE. Also, our results show that the FII C20221T is a rare variant in this population and therefore, routine thrombophilia screening should not include screening for this genotype.