20. What Kind of Diabetes?
Publisher: Springer London
This patient was diagnosed with assumed type 1 diabetes at the age of 20. She had several years of poor control and gained weight on insulin. Six years post-diagnosis a strong family history was revealed when her brother developed young-onset type 2 diabetes and it was also noted that her mother had diabetes. A C-peptide in the normal range showed that she continued to make endogenous insulin, which would be unusual in type 1 diabetes post-honeymoon period. Molecular genetic testing showed that the patient and her affected family members had maturity-onset diabetes of the young (MODY) due to a hepatocyte nuclear factor 1 alpha (HNF1A) mutation. Following this diagnosis she stopped basal-bolus insulin and her diabetes was managed on 40 mg gliclazide with improved HbA1c.