Diabetes in the young but not needing insulin--what type is it?

A 57-year-old female who was diagnosed with diabetes at the age of 22 is presented. She was initially controlled with diet alone and then was prescribed oral glucose lowering treatment over the next 35 years. She was referred to the diabetes clinic for insulin start because of poor control of diabetes. In view of her presentation at such a young age and strong family history, a possibility of maturity onset diabetes in young was considered and the genetic test confirmed hepatocyte nuclear factor-1 α mutation on chromosome 12. Further oral treatment and attention to lifestyle modification improved control avoiding insulin therapy.