83CliniCal MediCine insights: endoCrinology and diabetes 2015:8 Genetically Targeted Dipeptidyl Peptidase-4 Inhibitor Use in a Patient with a Novel Mutation of MODY type 4

ABSTRACT: Maturity onset diabetes of the young (MODY) is a rare form of diabetes mellitus typically seen in young adults that results from pancreatic beta-cell dysfunction. MODY4 is a rare subtype caused by a PDX1 mutation. In this case, we present a nonobese 26-year-old male with polyuria and poly-dipsia. Lab work showed a blood glucose of 511 mg/dL, no ketones or antibodies (insulin, islet cell, and glutamic acid decarboxylase [GAD]), C-peptide of 1.6 ng/mL, and A1c 9.3%. Genetic analysis revealed a novel nonsense mutation in the PDX1 gene, consistent with MODY type 4. Given this patient’s par-ticular genetic mutation affecting the incretin pathway, sitagliptin was substituted for glyburide, which led to significant improvement in glycemic control. Our case report identifies a unique mutation in a rare form of MODY and outlines management of ensuing diabetes through targeting its inherent genetic mutation