Maturity Onset Diabetes in the Young

In 1974, Tattersall and Fajans coined the term mature onset diabetes of the young (MODY). MODY is the most common form of monogenic diabetes and exhibits autosomal dominant inheritance. Patients with this form of diabetes can sometimes be mistaken for having either type 1 diabetes (DM1) or type 2 diabetes mellitus (DM2). It usually manifests before 25 years of age. This form of diabetes is non-ketotic, and patients do not have pancreatic autoantibodies. It is due to beta-cell dysfunction. Recognizing and understanding this syndrome is important in knowing whom to test. It also has implications for patients and families given the autosomal dominant inheritance, but also because certain genetic subtypes respond differently to treatment, have different complication rates, and some have other associated extra-pancreatic abnormalities involving kidneys, liver, intestines, etc. There are 6 widely recognized subtypes, but with ongoing advances in genetic testing, more are being recognized.