GAD2 and type 1 diabetes mellitus: The appearance of autoantibodies to one or several of the autoantigens -GAD65, IA-2, IAAs, ICA or ZnT8 signals an autoimmune pathogenesis of β-cell destruction and indicates condition‘s severity, the presence of multiple autoantibodies having the highest positive predictive value for type 1 diabetes [6, 21, 22].