Compared with that in LADA subjects, the frequency of GAD65-CAb was higher in young T1D, LADY, and old T1D subjects (57.6% vs. 33.3%, p < 0.001; 48.9% vs. 33.3%, p < 0.05; and 58.4% vs. 33.3%, p < 0.001, respectively), and the frequency of GAD65-MAb was higher in young T1D and LADY subjects than that in LADA subjects (60.0% vs. 42.3%, p < 0.05; 66.0% vs. 42.3%, p < 0.01, respectively), whereas the frequency of GAD65-NAb was higher in LADA subjects than that in young T1D subjects (20.5% vs. 7.3%, p < 0.01). The gene discussed is GAD2; the disease is type 1 diabetes mellitus.