Neonatal diabetes mellitus due to a novel ABCC8 gene mutation mimicking an organic acidemia.

Neonatal diabetes mellitus and organic acidemias, may present with similar features like hyperglycemia, ketoacidosis and failure to thrive. A four-mo-old girl presented with diabetic ketoacidosis following a febrile respiratory illness during which high anion gap metabolic acidosis and hyperglycemia were detected. She also had hyperammonemia, which led to diagnostic uncertainty. Euglycemia was achieved with insulin injections. Genotyping revealed a homozygous novel mutation of the ABCC8 gene coding for the SUR1 subunit of the pancreatic beta cell potassium channel. Subsequently, the child was successfully transitioned to oral glibenclamide therapy. Developmental delay was noted on follow-up which raised the possibility of intermediate DEND syndrome. A possible cause for hyperammonemia in neonatal diabetes mellitus has been postulated in the discussion.