Wambach JA, Marshall BA, Koster JC, White NH, Nichols CG. Successful sulfonylurea treatment of an insulin‐naïve neonate with diabetes mellitus due to a KCNJ11 mutation.

Activating mutations in the K_ATP‐channel cause neonatal diabetes mellitus (NDM), and patients have been safely transitioned from insulin to sulfonylureas. We report a male infant with permanent NDM (PNDM), born to a PNDM mother. Blood glucose began to rise on day of life (DOL) 2, and sulfonylurea (glyburide) therapy was initiated on DOL 5. Glucose was subsequently well controlled and normal at 3 months. A K_ATP mutation (R201H; KCNJ11) was detected in the infant, the mother, and 6‐yr‐old sister with PNDM; both were also subsequently transitioned off insulin onto glyburide. To our knowledge, this is the youngest NDM patient to receive oral glyburide and, importantly, the only one deliberately initiated on sulfonylureas. Strikingly, the current dose (0.017 mg/kg/d) is below the reported therapeutic range and approximately 75‐fold lower than doses required by the affected sister and mother. Pancreatic insulin disappears in an animal model of K_ATP‐induced NDM, unless glycemia is well controlled, thus, a dramatically lower glyburide requirement in the infant may reflect preserved insulin content because of early sulfonylurea intervention. Safe and effective initiation of glyburide in an insulin‐naïve neonatal patient with K_ATP‐dependent PNDM argues for early detection and sulfonylurea intervention.