title: Tumour necrosis factor (-308A) polymorphism in pre-eclampsia: meta-analysis of 16 case-control studies.
abstract: BACKGROUND
  The guanine to adenine transition at position -308 nucleotides in the tumour necrosis factor promoter region (TNF -308A) is a putative genetic risk factor for pre-eclampsia/eclampsia (PE/E). However, association studies have reported conflicting findings and have generally been underpowered to exclude modest effect sizes.
  
  
  OBJECTIVE
  To assess and synthesise the available evidence for the association of the TNF (-308A) polymorphism with PE/E.
  
  
  METHODS
  Systematic review and random effects meta-analysis of genetic association studies.
  
  
  RESULTS
  Sixteen eligible case-control studies in which a total of 1919 patients with PE/E and 2374 controls participated were identified. The studies were generally small but of reasonable methodological quality. Random effects meta-analysis improved the precision of the estimate of effect size but did not detect a statistically significant association: pooled relative risk 1.02 (95% confidence interval 0.86 to 1.20).
  
  
  CONCLUSIONS
  The available data are not consistent with more than a very modest association between the TNF (-308A) allele and PE/E. Screening pregnant women for this allele in order to guide antenatal surveillance or treatment is unwarranted. Future research efforts should focus on alternative candidate genes.
authors.affiliation: Australian National University Medical School, The Canberra Hospital, Woden, Australian Capital Territory, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Bombell
authors.forename: William
authors.initials: W
authors.lastname: McGuire
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D011110:Polymorphism, Genetic; D011225:Pre-Eclampsia / Q000235:genetics*; D011247:Pregnancy; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha