title: A genetic variation of the transcription factor 7-like 2 gene is associated with risk of type 2 diabetes in the Japanese population.
abstract: OBJECTIVE
  It has been suggested that transcription factor 7-like 2 protein (TCF7L2) plays an important role in glucose metabolism by regulating the production level of glucagon-like peptide-1, a hormone which modifies glucose-dependent insulin secretion. Recently, variants of TCF7L2 gene were reported to confer an increased risk of type 2 diabetes in three different samples from European and European-origin populations. We studied whether the single nucleotide polymorphisms (SNPs) in TCF7L2 were associated with type 2 diabetes in samples from a Japanese population.
  
  
  METHODS
  Five SNPs were genotyped in three different sample sets. Association with type 2 diabetes was investigated in each, as well as in combined sample sets.
  
  
  RESULTS
  The SNP rs7903146 was nominally associated with type 2 diabetes in the initial (p = 0.08) and two replication sample sets (p = 0.05 and 0.06). For the combined sample set, in which we successfully genotyped 1,174 type 2 diabetes patients and 823 control subjects, rs7903146 showed a significant association with type 2 diabetes (odds ratio = 1.69 [95% CI 1.21-2.36], p = 0.002) with the same direction as the previous reports in samples from European and European-origin populations. SNPs rs7903146 and rs7901695 were in complete linkage disequilibrium. The rest of the five SNPs (rs7895340, rs11196205 and rs12255372) did not show any significant associations with type 2 diabetes.
  
  
  CONCLUSIONS
  The consistent association between rs7903146 in TCF7L2 and type 2 diabetes in different ethnic groups, including the Japanese population, suggests that TCF7L2 is a common susceptibility gene for type 2 diabetes.
authors.affiliation: Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Horikoshi
authors.forename: K
authors.initials: K
authors.lastname: Hara
authors.forename: C
authors.initials: C
authors.lastname: Ito
authors.forename: R
authors.initials: R
authors.lastname: Nagai
authors.forename: P
authors.initials: P
authors.lastname: Froguel
authors.forename: T
authors.initials: T
authors.lastname: Kadowaki
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000208:ethnology / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007333:Insulin Resistance; D007564:Japan; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012306:Risk; D051820:TCF Transcription Factors / Q000235:genetics* / Q000502:physiology; D058118:Transcription Factor 7-Like 2 Protein
chemical_list: D051820:TCF Transcription Factors; C544894:TCF7L2 protein, human; D058118:Transcription Factor 7-Like 2 Protein