title: Association study of the genetic polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene and type 2 diabetes in the Chinese population.
abstract: OBJECTIVE
  Genetic polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene is one of the few validated genetic variants with large effects on the risk of type 2 diabetes in the populations of European ancestry. In this study, we aimed to explore the effect of the TCF7L2 polymorphisms in a Han Chinese population.
  
  
  METHODS
  We genotyped 20 single nucleotide polymorphisms (SNPs) across the TCF7L2 gene in 1,520 unrelated subjects from a Han Chinese population in Taiwan. The associations of SNPs and haplotypes with type 2 diabetes and linkage disequilibrium (LD) structure of the TCF7L2 gene were analyzed.
  
  
  RESULTS
  The previously reported SNPs rs7903146 T- and rs12255372 T-alleles of the TCF7L2 gene were rare and were not associated with type 2 diabetes in a Chinese population, which may attribute to the low frequencies of these two SNPs. SNP rs290487 located in an LD block close to the 3' end of the gene was associated with type 2 diabetes (allele-specific P = 0.0021; permuted P = 0.03). The odds ratio was 1.36 for the CT genotype (95% CI 1.08-1.71; P = 0.0063) and 1.51 for the CC genotype (1.10 -2.07; P = 0.0085) compared with the TT genotype, corresponding to a population attributable risk fraction of 18.7%. The haplotypes composed of rs290487 were also significantly associated with type 2 diabetes (global P = 0.012).
  
  
  CONCLUSIONS
  We identified a novel risk-conferring genetic variant of TCF7L2 for type 2 diabetes in a Chinese population. Our data suggested that the TCF7L2 genetic polymorphisms are major determinants for risk of type 2 diabetes in the Chinese population.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chang
authors.forename: Tien-Jyun
authors.initials: TJ
authors.lastname: Chang
authors.forename: Yi-Der
authors.initials: YD
authors.lastname: Jiang
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Kuo
authors.forename: Kuan-Ching
authors.initials: KC
authors.lastname: Lee
authors.forename: Ken C
authors.initials: KC
authors.lastname: Chiu
authors.forename: Lee-Ming
authors.initials: LM
authors.lastname: Chuang
mesh_terms: D000368:Aged; D002681:China; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D020224:Expressed Sequence Tags; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012016:Reference Values; D018570:Risk Assessment; D051820:TCF Transcription Factors / Q000235:genetics*; D058118:Transcription Factor 7-Like 2 Protein
chemical_list: D051820:TCF Transcription Factors; C544894:TCF7L2 protein, human; D058118:Transcription Factor 7-Like 2 Protein