HLA‐DQ and DRB1 polymorphism and susceptibility to type 1 diabetes in Jamaica

Abstract

SummaryGenetic susceptibility to type 1 diabetes is determined by a combination of HLA‐DQ and DRB1 alleles. In the present study, HLA associations with type 1 diabetes were investigated in the Jamaican population. DRB1 and DQ genotyping was performed on 45 type 1 diabetic patients and 132 control subjects born and resident in Jamaica. The small number of patients available for study reflected the low prevalence of type 1 diabetes in Jamaica. The results were compared with those from other African heritage populations and white Caucasians. The highest relative risk was associated with the DRB1*03‐DQ2/DRB1*04‐DQ8 genotype. Both DRB1*0401‐DQ8 and DRB1*0408‐DQ8 were positively associated with disease. DRB1*0408‐DQ8 is uncommon amongst white Caucasians, where DRB1*0401‐DQ8 is the major predisposing haplotype. The DRB1*1503‐DQ6 haplotype was associated with protection from diabetes in the Jamaican population. This haplotype is rare amongst white Caucasians, where DRB1*1501‐DQ6 is the protective haplotype. Data from African heritage populations suggest that DRB1*1503‐DQ6 might be less protective than DRB1*1501‐DQ6. DRB1*03‐DQA1*0401‐DQB1*0402 was associated with protection from diabetes in the Jamaican population, whereas in white Caucasians DRB1*08‐DQA1*0401‐DQB1*0402 is predisposing. These data demonstrate that comparison of genetic associations with type 1 diabetes in races with population‐specific DRB1‐DQ haplotypes provides new information as to the exact determinants of disease susceptibility. Further support is provided for roles of the DQ genes and the DRB1 gene (or a gene in linkage disequilibrium with it) in determining susceptibility to type 1 diabetes.

Part of CIRS Nexus · Curated by Lauren Lowenstein, The Biotoxin Lady