A recently described polymorphism in the CD28 gene on chromosome 2q33 is not associated with susceptibility to type 1 diabetes.
Type 1 diabetes mellitus is an autoimmune disease with a strong genetic background. The CTLA4 gene region (IDDM12) has been implicated in genetic susceptibility to type 1 diabetes by genome scanning and both family- and population-based analyses. As the genes encoding the costimulatory molecules CTLA4 and CD28, which compete for the receptor B7, reside close together on chromosome 2q33 and have high sequence homology, we investigated a recently described polymorphism in intron 3 of the CD28 gene and the CLTA4 codon 17 polymorphism in 176 patients with type 1 diabetes and 220 healthy controls. Whereas CTLA4 was found to be associated with type 1 diabetes, the frequency of the CD28 polymorphism did not differ between patients and controls, either in the entire sample or after stratification for CTLA4 genotype. Thus, the CD28 intron 3 polymorphism does not appear to be associated with susceptibility to type 1 diabetes.
Department of Internal Medicine I, Division of Endocrinology, University Hospital Frankfurt, Frankfurt am Main, Germany.
J P
JP
Wood
M A
MA
Pani
K
K
Bieda
G
G
Meyer
K-H
KH
Usadel
K
K
Badenhoop
D000069594:Abatacept; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics; D018106:CD28 Antigens / Q000235:genetics*; D060908:CTLA-4 Antigen; D002889:Chromosomes, Human, Pair 2; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D018796:Immunoconjugates; D011110:Polymorphism, Genetic
D015703:Antigens, CD; D000943:Antigens, Differentiation; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018796:Immunoconjugates; D000069594:Abatacept