title: Type 1 diabetes susceptibility determined by HLA alleles and CTLA-4 and insulin genes polymorphisms in Brazilians.
abstract: BACKGROUND
  Type 1A diabetes mellitus (T1ADM) is a multifactorial disease in which genetic and environmental aspects are important to its development. The association of genetic variations with disease has been demonstrated in several studies; however, the role of some gene loci has not yet been fully elucidated.
  
  
  OBJECTIVE
  To compare the frequency of HLA alleles and polymorphism in CTLA-4 and insulin genes in Brazilians with T1ADM and individuals without the disease, as well as to identify genetic markers that are able to discriminate between diabetic and non-diabetic individuals.
  
  
  METHODS
  The presence of HLA DQB1, DQA1 and DRB1 alleles, as well as the -2221 MspI polymorphism in the insulin gene and 49 A/G in the CTLA-4 gene were identified by the 'Time-resolved fluorometer' technique after hybridization with probes labeled with Eu (III) / Sm (III) and Tb (III).
  
  
  RESULTS
  The DQB1 *0302 and DQA1 *03 alleles were identified as predisposed to T1ADM, and the DQB1 *0301 allele presented a protective effect against the disease.The DQA1 label proved to be able to differentiate between 71.13% of the diabetic and non-diabetic individuals.This value increased to 82.47% when the DQB1 label was added. No significant difference in the frequency of polymorphisms in the insulin and CTLA-4 genes was observed between the two groups.
  
  
  CONCLUSIONS
  The genetic markers that best characterized and discriminated diabetic and non-diabetic individuals were the HLA DQA1 and DQB1.alleles.
authors: Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil. alessandro@labhpardini.com.br
authors: Alessandro Clayton Souza
authors: AC
authors: Ferreira
authors: Karina Braga
authors: KB
authors: Gomes
authors: Ivan Barbosa Machado
authors: IB
authors: Sampaio
authors: Vanessa Cristina de
authors: VC
authors: Oliveira
authors: Victor Cavalcanti
authors: VC
authors: Pardini
authors: Ana Lucia Brunialti
authors: AL
authors: Godard
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D015703:Antigens, CD / Q000235:genetics*; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D016002:Discriminant Analysis; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006681:HLA-D Antigens / Q000235:genetics*; D006801:Humans; D007328:Insulin / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*
chemical_list: D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D006681:HLA-D Antigens; D007328:Insulin