title: Progress in the genetics of common obesity: size matters.
abstract: OBJECTIVE
  Over the past two decades serious efforts has been invested in the search for genes that predispose to common obesity, but progress has been slow and success limited. Genome-wide association, however, has revived optimism. Here we review recent advances in the field of obesity genetics and discuss the most important findings of candidate gene, genome-wide linkage studies and genome-wide association studies. We conclude by speculating about the way forward in the near future.
  
  
  RESULTS
  Although large-scale candidate gene studies have placed MC4R more firmly on the human obesity map, the major breakthrough in obesity genetics was the discovery of FTO through genome-wide association. Variants located in the first intron of FTO were unequivocally associated with a 1.67-fold increased risk for obesity and a 0.40-0.66 kg/m2 increase in body mass index.
  
  
  CONCLUSIONS
  Genome-wide association promises to enhance greatly our understanding of the genetic basis of common obesity, although candidate gene studies will remain a valuable approach because they allow more detailed analyses of biologically relevant candidates. A key factor contributing to continued success lies in large-scale data integration through international collaboration, which will provide the sample sizes required to identify genetic association with conclusive evidence.
authors.affiliation: Medical Research Council Epidemiology Unit, Institute of Metabolic Science, Cambridge, UK.
authors.forename: Shengxu
authors.initials: S
authors.lastname: Li
authors.forename: Ruth J F
authors.initials: RJ
authors.lastname: Loos
mesh_terms: D018450:Disease Progression; D005786:Gene Expression Regulation; D016678:Genome / Q000235:genetics; D006801:Humans; D009765:Obesity / Q000235:genetics*; D018401:Sample Size