Primary role of the HLA class II DRB1*0301 allele in Graves disease

The association of the Graves disease (GD) with HLA DR3 and DQA1*0501 in Ca ucasians has been described previously. From these studies it could not be determined whether one specific locus was primarily involved, Using a case- control study design, we have examined the role of HLA class II gene polymo rphisms in the predisposition for GD in a group of Belgian subjects. We dem onstrated that both DRB1*0301 and DQA1*0501 alleles conferred significant s usceptibility in the DRB1*0301-D&A1*0501 haplotype,The DRB1*0301 allele was the primary susceptibility allele for GD, however, because the susceptibil ity provided by D&A1*0501 was most likely due to it being in linkage disequ ilibrium with DRB1*0301. The DRB1*0701/x and DQA1*0201/x genotypes and the DRB1*0701-DQA1*0201 haplotype provided protection with an equal. RR of 0.29 , Predictive value calculations showed that testing for DRB1*0301 gave the highest positive predictive Value for GD in females and males. This was, ho wever, 10 times higher in females and predicted a 3.63% risk for a random f emale to develop GD, (C) 2000 Wiley-Liss, Inc.