Another less common form of diabetes is maturity-onset diabetes of the young (MODY), which is a monogenic diabetes that leads to a defect in β cell insulin secretion.1-3 Patients with MODY may be misdiagnosed with either type 1 diabetes (T1D) or type 2 diabetes (T2D) depending on age and presentation (Table).
MODY is categorized into 14 known subtypes based on the genes affected. The 2 most common are MODY 2 and MODY 3, which result from defects in the glucokinase and hepatocyte nuclear factor-1α genes, respectively.1-3 Typically diagnosed when they are <25 years of age, patients with MODY lack insulin resistance and overweight/obesity commonly associated with T2D and autoantibodies associated with T1D.
Patients with MODY have a strong family history of diabetes in an autosomal-dominant pattern (more than 2 generations). Genetic testing confirms the diagnosis.1,2 Lifestyle modification is appropriate for both MODY 2 and 3, and patients with MODY 3 respond well to treatment with sulfonylurea agents. Progression to insulin dependence is infrequent in patients with MODY.2,3
- Carlsson A, Shepherd M, Ellard S, et al. Absence of islet autoantibodies and modestly raised glucose values at diabetes diagnosis should lead to testing for MODY: lessons from a 5-year pediatric Swedish national cohort study. Diabetes Care. 2020;43(1):82-89.
- Delvecchio M, Salzano G, Bonura C, et al. Can HbA1c combined with fasting plasma glucose help to assess priority for GCK-MODY vs HNF1A-MODY genetic testing? Acta Diabetol. 2018;55(9):981-983.
- Urakami T. Maturity-onset diabetes of the young (MODY): current perspectives on diagnosis and treatment. Diabetes Metab Syndr Obes. 2019;12:1047-1056.