677 C -> T polymorphism of the methylenetetrahydrofolate reductase gene and preeclampsia

Objective: To evaluate C to T substitution at nucleotide 677 of N-5,N-10-me thylenetetrahydrofolate reductase gene in women with prior preeclamptic or normotensive pregnancies. Methods: Methylenetetrahydrofolate reductase genotypes were determined in 1 13 Finnish women with preeclamptic first pregnancies and 103 controls with one or more normotensive pregnancies, using polymerase chain reaction and r estriction enzyme analysis. Preeclampsia was defined as severe in 100 women who fulfilled one or more of the subsequent criteria: systolic blood press ure (BP) at least 160 mmHg, diastolic BP at least 110 mmHg, or proteinuria at least 2 g per 24-hour urine collection. Results: There were no significant differences in prevalences of the methyl enetetrahydrofolate reductase genotypes (CC, CT, and TT) between groups (57 %, 40%, and 3% in the preedamptic group and 54%, 39%, and 7%, respectively, in controls). The frequency of the T677 allele was 0.23 in the preeclampti c group and 0.26 in the control group (difference 0.03; 95% confidence inte rval -0.08, 0.14; P = .51). Our sample had 60% power to detect a difference of the allele frequencies similar to that (0.12) reported previously. The result was similar when analysis was restricted to patients with severe pre eclampsia (T677 allele frequency 0.22). Conclusion: A carrier status for the T677 allele of the methylenetetrahydro folate reductase gene does not predispose to preeclampsia, at least in the Finnish population. ((C) 2000 by The American College of Obstetricians and Gynecologists.).