Case report, Monogenic diabetes, Neonatal diabetes mellitus, Variable clinical phenotype presentation, Incomplete penetrance, Sulfonylurea treatment Switching from insulin to oral sulfonylureas in patients with diabetes due to Kir6.2 mutations. Keywords: Case report; Monogenic diabetes; Neonatal diabetes mellitus; Sulfonylurea treatment; Variable clinical phenotype presentation; Incomplete penetrance EN Case report Monogenic diabetes Neonatal diabetes mellitus Sulfonylurea treatment Variable clinical phenotype presentation Incomplete penetrance 989 993 5 05/23/23 20230701 NES 230701 Introduction Neonatal diabetes mellitus (NDM) is a disorder of the glycemic status occurring in the first 6 months of life. [Extracted from the article]