Differentiating Among Type 1, Type 2 Diabetes, and MODY: Raising Awareness About the Clinical Implementation of Genetic Testing in Latin America

To describe a case of maturity-onset diabetes of the young (MODY) to highlight the importance of a correct diabetes diagnosis. We describe a Mexican family misdiagnosed with T1D and T2D. A 36-year-old woman with diabetes and adverse outcomes during 2 pregnancies had been diagnosed with T2D 10 years ago. Genetic testing was performed due to clinical and family history, which showed a pathogenic heterozygous variant c.544G>T (p.Val182Leu) in the GCK gene. This mutation was also confirmed in most of the family members who had been diagnosed with diabetes. This case highlights the need for a correct diabetes classification. Reassessment of diabetes etiology is justified, especially in individuals with unclear clinical presentation or when family history is suggestive.