Methylenetetrahydrofolate reductase 677 C --> T polymorphism, plasma folate, vitamin B(12) concentrations, and risk of preeclampsia among black African women from Zimbabwe

Mol Genet Metab. 2000 Jan;69(1):33-9. doi: 10.1006/mgme.1999.2952.


We conducted a case control study at Harare Maternity Hospital, Zimbabwe. We genotyped a total of 171 cases with preeclampsia or eclampsia and 185 normotensive control subjects for the methylenetetrahydrofolate reductase (MTHFR) 677 C --> T genotype. The wild-type allele frequency among cases and controls was 91.2 and 91.3%, respectively. Only one subject (0.3%) was homozygous for the 677 C --> T MTHFR genotype and this subject had preeclampsia. After adjustment for confounding factors, there was statistically no significant association between maternal MTHFR genotype and risk of preeclampsia (adjusted odds ratio = 1.0; 95% CI, 0.5-1.9). In addition, plasma homocyst(e)ine, vitamin B(12), and folate concentrations were not statistically different between normotensive control subjects with wild-type genotype as compared with normotensive subjects who were heterozygous for the mutant allele. Conversely, there was a strong graded association between maternal plasma folate concentration and risk of preeclampsia. Women with plasma folate concentrations less than 5.7 nmol/L experienced a 10. 4-fold increase in risk of preeclampsia. There was no clear pattern of preeclampsia risk and vitamin B(12) concentrations.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Blacks / genetics
  • Case-Control Studies
  • Female
  • Folic Acid / blood*
  • Gene Frequency
  • Genetic Predisposition to Disease / genetics
  • Genotype
  • Homocysteine / blood
  • Humans
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Mutation / genetics
  • Nutritional Physiological Phenomena
  • Odds Ratio
  • Oxidoreductases Acting on CH-NH Group Donors / genetics*
  • Polymorphism, Single Nucleotide / genetics*
  • Pre-Eclampsia / blood*
  • Pre-Eclampsia / enzymology
  • Pre-Eclampsia / etiology
  • Pre-Eclampsia / genetics*
  • Pregnancy
  • Risk Factors
  • Vitamin B 12 / blood*
  • Zimbabwe


  • Homocysteine
  • Folic Acid
  • Oxidoreductases Acting on CH-NH Group Donors
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Vitamin B 12