Noticeably, young T1D, LADY, and old T1D patients showed higher levels of reactivity against multiple epitopes of GAD65 than the levels of LADA patients (44.2% vs. 26.9%, p < 0.05; 45.7% vs. 26.9%, p < 0.05; and 43.6% vs. 26.9%, p < 0.05, respectively). This evidence concerns the gene GAD2 and type 1 diabetes mellitus.