Implication of HLA-DMA alleles in Corsican IDDM

The HT,A-DM molecule catalyses the CLIP/antigen peptide exchange in the cla ssical class II peptide-binding groove. As such, DM is an antigen presentat ion regulator and may be linked to autoimmune diseases. Using PCR derived m ethods, a relationship was revealed between DM gene polymorphism and IDDM, in a Corsican population. The DMA*0101 allele was observed to confer a sign ificant predisposition to this autoimmune disease while the DMA*0102 allele protected significantly. Experiments examining polymorphism of the HLA-DRB 1 gene established that these relationships are not a consequence of linkag e disequilibrium with HLA-DRB1 alleles implicated in this pathology. The st udy of the DMA gene could therefore be an additional tool for early IDDM di agnosis in the Corsican population.