title: Anorexia nervosa and the Val158Met polymorphism of the COMT gene:  meta-analysis and new data.
abstract: OBJECTIVE
  This study aimed to test the association between the Val158Met polymorphism (rs4680) of the catechol-O-methyl transferase gene and anorexia nervosa (AN).
  
  
  METHODS
  First, an association study on two cohorts (306 cases and 1009 controls from Utrecht, and 174 cases and 466 controls from Leiden/NTR) was performed. Subsequently, the results were integrated into a meta-analysis, together with all the case-control and family-based studies, which were testing the same hypothesis and were available in the literature. Altogether, eight studies (11 datasets) were included in this meta-analysis, with a total of 2021 cases, 2848 controls, and 89 informative (heterozygous) trios.
  
  
  RESULTS
  The present association studies found no association between AN and rs4680 when testing the allelic contrast [Utrecht odds ratio (OR)=1.14, P=0.14; Leiden OR=1.02, P=0.85]. There was an indication of an association under the dominant model of genetic effect in the Utrecht cohort (for the Met allele, OR=1.42, P=0.03). Nevertheless, the meta-analyses of both the allelic contrast and the dominant effect were nonsignificant (the allelic pooled OR=1.03, P=0.42 and the dominant pooled OR=1.1, P=0.18). The meta-analyses were performed under the fixed-effect model and there was no significant heterogeneity among the effect sizes.
  
  
  CONCLUSIONS
  Meta-analytically combined evidence from the present genotypings and the literature search shows that the effect sizes are homogeneous across studies and that rs4680 is not associated with AN.
authors.affiliation: Department of Neuroscience, Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, The Netherlands.
authors.forename: Marek K
authors.initials: MK
authors.lastname: Brandys
authors.forename: Margarita C T
authors.initials: MC
authors.lastname: Slof-Op't Landt
authors.forename: Annemarie A
authors.initials: AA
authors.lastname: van Elburg
authors.forename: Roel
authors.initials: R
authors.lastname: Ophoff
authors.forename: Willem
authors.initials: W
authors.lastname: Verduijn
authors.forename: Ingrid
authors.initials: I
authors.lastname: Meulenbelt
authors.forename: Christel M
authors.initials: CM
authors.lastname: Middeldorp
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: Eric F
authors.initials: EF
authors.lastname: van Furth
authors.forename: Eline
authors.initials: E
authors.lastname: Slagboom
authors.forename: Martien J H
authors.initials: MJ
authors.lastname: Kas
authors.forename: Roger A H
authors.initials: RA
authors.lastname: Adan
mesh_terms: D000856:Anorexia Nervosa / Q000235:genetics*; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics*; D011110:Polymorphism, Genetic; D014633:Valine / Q000235:genetics*
chemical_list: D008715:Methionine; D002394:Catechol O-Methyltransferase; D014633:Valine