Endocrine Abstracts

Background: Maturity-onset diabetes of the young (MODY) is a group of 13 monogenic forms of diabetes transmitted in an autosomal dominant pattern and is characterized by a primary defect in pancreatic β-cell function. This disease has an early onset, usually before 25 years of age. It may present with mild asymptomatic hyperglycemia with progressive development to clinical diabetes mellitus. First-line treatment relies on sulphonylureas or insulin according to MODY subtype.

Case Presentation: This is a case of 55 years old lady who was diagnosed with type 1 diabetes at the age of 29 years. She was started on basal-bolus insulin initially and moved onto insulin pump later. At that time, type 1 diabetes was diagnosed on the clinical grounds, high HbA1c and high insulin requirement. Recently her sister got diagnosed with MODY (HNF-1 Alpha gene defect) at the age of 48 years. Due to family history, our patient was tested for MODY. She was 55 years old at the time. Relevant investigations like insulin auto antibodies, C- peptide and Insulin level was requested which was followed by genetic testing. Her daily insulin requirement and glycemic control was reviewed. Blood results showed that her antibodies to Glutamic acid decarboxylase and Islet cell came back negative with a healthy C-peptide and Insulin level, which points towards a probable diagnosis of MODY. Subsequently, her genetic testing showed HNF-4 Alpha gene defect. On careful review of her glycemic control, we found that her insulin requirement were consistently about 0.3 units/kg, which is not expected of type 1 diabetes 25 years into the diagnosis. Her HbA1c was maintained around 51 mmol/mol (6.8%).

Conclusion: We can say that MODY can present above the age of 45 years. In our clinical practice, we should always review the diagnosis of diabetes if there are clinical concerns.