title: Association of a novel point mutation (C159G) of the CTLA4 gene with type 1 diabetes in West Africans but not in Chinese.
abstract: Here, we report on the detection of a novel point mutation of the CTLA4 gene at nucleotide position 159 (C-->G) leading to amino acid substitution at position 53 (I-->M), as well as its association with type 1 diabetes in two ethnically distinct populations. Subjects included 182 unrelated type 1 diabetes children and 201 control subjects from Ghana, West Africa. The Chinese study population consisted of 350 type 1 diabetic children and 420 healthy control subjects from central China. Polymerase chain reaction-single-strand conformation polymorphism and sequence analysis were used to screen for polymorphisms in the CTLA4 gene. CTLA4 49 (A-->G) mutation conferred a risk of type 1 diabetes in the Chinese children (odds ratio 1.78, 95% CI 1.58-2.0), but not in the West African children (1.17, 0.84-1.64). On the other hand, the novel CTLA4 159 (C-->G) mutation conferred a risk of type 1 diabetes in the West African children (2.1, 1.54-2.86), but not in the Chinese type 1 diabetic children. The novel CTLA4 gene polymorphism at nucleotide position 159 significantly associated with type 1 diabetes in West Africans, but not in Chinese. On the other hand, the CTLA4 gene polymorphism at nucleotide position 49 significantly associated with type 1 diabetes in Chinese, but not in West Africans.
authors.affiliation: Graduate School of Medicine, University of Tsukuba, Tsukuba city, Ibaraki-ken, Japan. dhyiaman@mail.nih.gov
authors.forename: D
authors.initials: D
authors.lastname: Osei-Hyiaman
authors.forename: L
authors.initials: L
authors.lastname: Hou
authors.forename: R
authors.initials: R
authors.lastname: Zhiyin
authors.forename: Z
authors.initials: Z
authors.lastname: Zhiming
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.forename: A A
authors.initials: AA
authors.lastname: Amankwah
authors.forename: S
authors.initials: S
authors.lastname: Harada
mesh_terms: D000069594:Abatacept; D000293:Adolescent; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics*; D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics*; D060908:CTLA-4 Antigen; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D005869:Ghana / Q000208:ethnology; D006801:Humans; D018796:Immunoconjugates; D007223:Infant; D008297:Male; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018796:Immunoconjugates; D000069594:Abatacept