title: Association of CTLA4 gene A-G polymorphism with type 1 diabetes in Chinese children.
abstract: OBJECTIVE
  The CTLA4 (cytotoxic T lymphocyte associated antigen-4) gene encodes the T cell receptor involved in the control of T cell proliferation and mediates T cell apoptosis. Thus it is a strong candidate gene for T cell-mediated autoimmune disease. There is polymorphism at position 49 in exon 1 of the CTLA4 gene, providing a A-G exchange. This polymorphism is reportedly associated with type 1 diabetes in Caucasians but not in a small data set of Chinese. We wished to test this polymorphism in a larger and more homogeneous data set of Chinese children with type 1 diabetes and normal adult controls.
  
  
  METHODS
  A population-based case-control study of a CTLA4 gene 49 A-G polymorphism was performed to look for an association with type 1 diabetes in Chinese children.
  
  
  METHODS
  We analysed this polymorphism in 253 unrelated children (128 boys) with type 1 diabetes (age at diagnosis 7.1 +/- 3.7 years) and 91 randomly selected normal adults. All individuals were Han Chinese.
  
  
  RESULTS
  The genotype and gene frequencies of children with type 1 diabetes differed significantly from those of adult controls (P = 0.0091 and P = 0.0051, respectively). Genotype CTLA4 49 G/G and G allele conferred a risk of type 1 diabetes (RR = 2.13, 95% CI = 1.31-3.46, P = 0.0022; RR = 1.68, 95% CI = 1.17-2.43, P = 0.0051, respectively).
  
  
  CONCLUSIONS
  This study demonstrates that CTLA4 49 A-G polymorphism is associated with type 1 diabetes in Han Chinese children. The CTLA4 49 G allele confers an increased risk of type 1 diabetes.
authors.affiliation: Departments of Paediatrics; Medical Research, Mackay Memorial Hospital, Taipei, Taiwan. yanlee@ms2.mmh.org.tw
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lee
authors.forename: F Y
authors.initials: FY
authors.lastname: Huang
authors.forename: F S
authors.initials: FS
authors.lastname: Lo
authors.forename: W C
authors.initials: WC
authors.lastname: Wang
authors.forename: C H
authors.initials: CH
authors.lastname: Hsu
authors.forename: H A
authors.initials: HA
authors.lastname: Kao
authors.forename: T Y
authors.initials: TY
authors.lastname: Yang
authors.forename: J G
authors.initials: JG
authors.lastname: Chang
mesh_terms: D000069594:Abatacept; D000293:Adolescent; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China; D016001:Confidence Intervals; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology / Q000235:genetics*; D005260:Female; D006801:Humans; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D007223:Infant; D008297:Male; D011110:Polymorphism, Genetic; D012306:Risk
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D000069594:Abatacept