Maturity-Onset Diabetes of the Young Type 3 (MODY 3): A Rare Presentation of Diabetes in Primary Care.

Maturity-onset diabetes of the young (MODY) is a genetic form of diabetes with an autosomal dominant pattern of transmission characterized by dysfunction in pancreatic β-cells. MODY type 3 (MODY 3) is caused by heterozygous mutations in the hepatocyte nuclear factor 1-α (HNF1A) gene and is sensitive to treatment with sulfonylureas. This case report approaches the diagnostic journey of a 46-year-old woman who was initially misdiagnosed with type 2 diabetes.