The motif “DCAA-YSARD”, corresponding to DQA1*05:01-B1*02:01 and A1*05:05-B1*02:01, was significantly associated with susceptibility to T1D (OR = 2.10, p = 1.96*10−20), and is equivalent to the traditionally known DQ2.5 serotype. The gene discussed is HLA-DQA1; the disease is type 1 diabetes mellitus.