For example, two distinct HLA molecules not closely related but both risk associated, HLA-DQA1 *03:01 and *05:01, shared an extended haplotype of 10 amino acid residues (DQA Y11R52R55F61T64I66L69V/L76H129E/K175) all found to be significantly associated with disease susceptibility and all entirely different from all other DQA alleles suggesting that this constitutes a shared epitope for T1D. Here, HLA-DQA1 is linked to type 1 diabetes mellitus.