Multiple genes in the HLA region of chromosome 6 are known to increase the risk of developing T1D.  However, if you can only select one molecule to study, it would be best to study the HLA-DQ antigen. HLA-DQ antigens are found on the surface of cells involved in immune response.  Since T1D is an autoimmune disease, it is likely that the reason these antigens increase susceptibility to the disease is because they can sometimes have a ‘negative’ impact on the immune system.

 

The HLA-DQ antigen is comprised of 2 molecules – the β chain and the α chain.  These are encoded by the DQB1 and DQA1 genes, respectively.  Because everyone has 2 chromosomes, they will have 2 DQA1 alleles and 2 DQB1 alleles.