Poorly controlled T2D (HbA1c: 11.6%) in the presence of detectable levels of C-peptide (1.64 ng/mL, normal range 0.69-2,45 ng/mL) was found and undetectable titre of antibodies against pancreatic islets’ antigens (ICA, GAD, IA2) were confirmed. Here, GAD1 is linked to type 2 diabetes mellitus.