Successful Transition From Insulin to Sulfonylurea Therapy in a Patient With Monogenic Neonatal Diabetes Owing to a KCNJ11 F333L Mutation

Although monogenic neonatal diabetes may be caused by mutations in >20 different genes, the most common are activating heterozygous mutations in KCNJ11, encoding the Kir6.2 subunit of the ATP-sensitive K+ channel (KATP channel), which is highly expressed in pancreatic β-cells and brain (1). Mutated KATP channels typically have decreased sensitivity to ATP inhibition, hampering insulin secretion even during hyperglycemia. Oral sulfonylureas (SUs) have been demonstrated to be an effective treatment in the majority of cases, given that they close the KATP channels by an ATP-independent mechanism (2). However, the likelihood of success is largely predicted by the particular mutation. Previous reports of the F333L mutation indicated insensitivity to SU therapy. We report a case representing a novel response to SU therapy in this same mutation.A 13-month …