[Distribution and frequency of HLA alleles and haplotypes in Brazilians with type 1 diabetes mellitus].
The genetic predisposition to type 1 diabetes (DM1) is associated with genes of the human leukocyte antigen (HLA) system, specially the HLA-DR and -DQ. In Caucasians, the HLA-DR3 and -DR4 antigens are associated with susceptibility and the -DR2, with protection. In Brazil, a country with a large miscegenation of European Caucasians, Native Amerindians and African Blacks, the genetic basis of DM1 has not been adequately studied. The aim of this paper is to present a critical review of articles indexed in the MEDLINE and LILACS-BIREME data basis about the association of HLA with DM1 in Brazilians. Eight papers, all of them from the Southeast region, were found. Immunogenetic susceptibility to DM1 in Brazilians was associated with HLA-DRB1*03, -DRB*04, -DQB1*0201, -DQB1*0302 alleles, and protection against DM1 was associated with HLA-DQB1*0602, -DQB1*0301 alleles and -DR2 and -DR7 antigens. Since the Brazilian population is not racially homogeneous, it is not possible to extrapolate studies from a single region to the remainder of the country. It is necessary to study populations from different regions to identify new associations or to strengthen associations with the ones already identified. This knowledge will contribute to future prophylactic or therapeutic interventions in the group of Brazilians at risk of developing DM1.
Alves
Crésio
C
Faculdade de Medicina, Universidade Federal da Bahia, Rua Plínio Moscoso 222, 40157-190 Salvador, BA. cresio.alves@uol.com.br
Meyer
Isadora
I
Vieira
Nara
N
Toralles
Maria Betânia P
MB
LeMaire
Denise
D
D000483:Alleles; D001938:Brazil / Q000208:ethnology; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006680:HLA Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000097:blood; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins / Q000097:blood
D006680:HLA Antigens; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins