title: Tumour necrosis factor gene polymorphisms and migraine: a systematic review and meta-analysis.
abstract: BACKGROUND
  Data on the association between TNFα and TNFβ gene polymorphisms and migraine are conflicting.
  
  
  METHODS
  We performed a systematic review and meta-analysis of studies published until January 2011. We used data from published papers and as provided after contact with the authors. We calculated study specific odds ratios (OR) and 95% confidence intervals (CI) assuming additive, dominant, and recessive genetic models as well as pooled effect estimates.
  
  
  RESULTS
  Among the ten studies identified, the best evidence is available for the TNFα -308G>A and TNFβ 252A > G polymorphisms indicating no overall association with migraine. Subgroup analyses suggested that the A allele of the TNFα -308G > A variant more than doubles the risk for migraine among populations with a heterogeneous ethnic background, which was driven by associations for migraine without aura (additive model: pooled OR = 2.87, 95% CI 1.86-4.43). Further, the risk for migraine with aura was increased among Asian populations (additive model: pooled OR = 1.71, 95% CI 1.07-2.71). Both observed effects were stronger among females than males.
  
  
  CONCLUSIONS
  Our results indicate no overall association between TNFα and TNFβ gene variants and migraine. However, associations differed among specific populations. Our findings need to be treated with caution and further targeted research is warranted to evaluate population-specific effects including population stratification.
authors: Division of Preventive Medicine, Brigham and Women’s Hospital, 900 Commonwealth Avenue East, 3rd f, Boston, MA 02215-1204, USA. markus.schuerks@post.harvard.edu
authors: Markus
authors: M
authors: Schürks
authors: Pamela M
authors: PM
authors: Rist
authors: Robert Yl
authors: RY
authors: Zee
authors: Daniel I
authors: DI
authors: Chasman
authors: Tobias
authors: T
authors: Kurth
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008233:Lymphotoxin-alpha / Q000235:genetics*; D008297:Male; D008881:Migraine Disorders / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D008957:Models, Genetic; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D017678:Sex Distribution; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha