title: Concordance of functional in vitro data and epidemiological associations in complex disease genetics.
abstract: OBJECTIVE
  We aimed to assess whether epidemiological evidence on genetic associations for complex diseases concord with in vitro functional data.
  
  
  METHODS
  We examined 36 studies on bi-allelic markers and 23 studies on haplotypes where investigators had addressed both epidemiological associations and the functional effect of the same gene variants in luciferase reporter systems in vitro.
  
  
  RESULTS
  There was no correlation between epidemiological odds ratios and luciferase activity ratios (-0.09, P = 0.60). Luciferase activity ratios could not tell whether a probed epidemiologic association would be significant or not (area under receiver operating characteristics curve, 0.52). Luciferase results usually were qualitatively similar across cell lines and experimental conditions, with some exceptions. A luciferase activity ratio of 1.44 adequately separated statistically significant from non-significant functional differences (area under receiver operating characteristics curve, 0.95). Binary and continuous disease outcomes usually gave concordant results; other in vitro methods, in particular EMSA, agreed with luciferase results. Selective reporting and use of different variants and contrasts between functional and epidemiological analyses were common in these studies.
  
  
  CONCLUSIONS
  In vitro biological data and epidemiology provide independent lines of evidence on complex diseases. We provide suggestions for improving the design and reporting of studies addressing both in vitro and epidemiological effects.
authors.affiliation: Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece.
authors.forename: John P A
authors.initials: JP
authors.lastname: Ioannidis
authors.forename: Fotini K
authors.initials: FK
authors.lastname: Kavvoura
mesh_terms: D000483:Alleles; D000818:Animals; D003627:Data Interpretation, Statistical; D004812:Epidemiologic Methods; D017930:Genes, Reporter; D030342:Genetic Diseases, Inborn / Q000453:epidemiology*; D014644:Genetic Variation; D005826:Genetics, Medical; D006239:Haplotypes; D006801:Humans; D066298:In Vitro Techniques; D008156:Luciferases / Q000235:genetics; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D014162:Transfection
chemical_list: D008156:Luciferases