PTPRN and Insulin resistance: Her lean body habitus, absence of clinical insulin resistance, progressive glycemic deterioration, autoimmune background, and musculoskeletal manifestations prompted further evaluation, which revealed markedly elevated pancreatic autoantibodies, including glutamic acid decarboxylase (GAD-65), islet antigen-2 (IA-2), and zinc transporter 8 (ZnT8) antibodies, confirming the diagnosis of LADA with evolving β-cell failure.