The 4G/5G polymorphism of the plasminogen activator inhibitor-1 gene is associated with severe preeclampsia.

Preeclampsia is associated with thrombosis of the intervillous or spiral artery. A deletion/insertion polymorphism (4G or 5G) in the promoter of the plasminogen activator inhibitor type 1 (PAI-1) gene is suggested to be involved in regulating the synthesis of the inhibitor, 4G allele, being associated with the enhanced gene expression and plasma PAI-1 levels. We assessed the association between preeclampsia and the 4G/5G polymorphism of the PAI-1 gene in 115 preeclamptic patients, 210 pregnant controls, and 298 healthy volunteer controls. The frequency of the homozygotes for the 4G allele was significantly higher in the patients than in the control pregnant women (P = 0.04) or in the healthy volunteers (P = 0.02). The 4G allele frequency was also significantly higher in the patients than in the control group of pregnant women (P = 0.03) and in the healthy volunteers (P = 0.02). These results suggest that the presence of the 4G/4G genotype of the PAI-1 gene is one of the risk factors for preeclampsia.