POLYMORPHISM IN THE UPSTREAM REGULATORY REGION OF DQA1 GENE IN THE ITALIAN POPULATION

Polymorphism in the 5'-upstream regulatory region of the DQA1 gene has been recently described. Using PCR-SSO method and SSCP analysis we ha ve investigated this polymorphism in a group of 111 Italian blood dono rs which had been oligotyped for DRB1, DQA1 and DQB1 genes. Eight alle lic variants were detected. Looking at the relationships among QAP seq uences and DQA1 and DRB1 genes, three alternative situations were foun d: 1. a one-to-one relation between QAP and DQA1 alleles, independentl y of the other class II genes; 2. the same QAP allele in association w ith different DQA1-DRB1 haplotypes; 3. the same DQA1 allele with diffe rent QAP sequences according to the DRB1 specificity. No unexpected as sociations with DQB1 gene were found. These results must be interprete d considering that DQA1 and DRB1 genes are transcribed in opposite dir ections so that the promoter region of DQA1 gene lies between DQA1 and DRB1, close to the former but several hundreds kb away from the latte r.