Genetic differences in HLA-DQA1* and DQB1* allelic distributions between celiac and control children in Santiago, Chile

Celiac disease is a permanent gluten intolerance strongly associated with H LA class II antigens, The over presentation of particular HLA alleles and h aplotypes has been described in several populations. Different lines of evi dence obtained during the last years suggest that a particular HLA-DQ heter odimer, encoded by the DQA1*0501 and DQB1*0201 genes in cis or trans confor mation, confers the primary disease susceptibility. We report the HLA class II allelic distribution and DQA1/ DQB1 genotypes in 62 Chilean celiac pati ents compared with 124 control subjects in Santiago, Chile. We found a pron ounced increase of the "susceptible alleles :DQA1+0501 (0.480 vs 0.163, P-c < 0.0005), DQB1*0302 (0.-430 vs 0.242, P-c = 0.002) and DQB1*0201 (0.250 v s 0.125, P-c = 0.037) in celiac patients in comparison with control childre n. As for "protective" alleles, we detected a high frequency of DQA1*0101 ( 0.310 vs 0.160 P-c = 0 01), DQA1*0201 (0.105 vs 0.010, P-c < 0.0075) and DQ B1*0381 (0.250 vs 0.1001 P-c = 0.010) in controls. In relation to risk hapl otylzes, the main combination observed was the conformation DQ8 (DQB1*0302/ DQA1*0301) over DQ2 (DQB1*0201/DQA1*0501), In conclusion, results show that celiac disease in Chilean patients is primarily! associated with DQ8 confo rmation. This is concordant with the high Frequency of DR-I alleles tin lin kage disequilibrium with DQB1*0302) detected in Amerind groups in Chile, wh ere DQB1*0302 is more frequent than DQBI*0201. Human Immunology 60, 262-267 (1999) (C)American Society for Histocompaltibility and Immunogeneties, 199 9 published by Elsevier Science Inc.