[Striking manifestation and unexpected therapeutic course of diabetes mellitus in a 22-year-old male patient]

The case of a 22-year-old male patient who presented with acute on chronic hyperglycemia in known MODY ("maturity onset diabetes of the young") 12 (ABCC8 gene) after 11 months of treatment cessation is reported. To emphasize the importance of the awareness of this therapeutically important entity of diabetes, the essential facts of this inherited disease are summarized.