GAD2 and diabetes mellitus: The KPD diagnosis was based on the occurrence of spontaneous severe ketoacidosis in individuals with diabetes diagnosis not classifiable in the classic diabetes types, age above 30 years, absence of antiglutamic acid decarboxylase antibodies (GAD-65) and beta-cell function reserve after correction of ketoacidosis (fasting C-peptide level least 1 ng/mL; normal range [nr]: 1.1-4.4 ng/mL; immunofluorometric assay (Auto Delfia, Finland) with a detection limit of 0.10 ng/mL), criteria previously established by Maldonado and cols.