6q24-Related Transient Neonatal Diabetes Mellitus Presenting With Severe Diabetic Ketoacidosis and Multiorgan Failure.

Neonatal diabetes is commonly defined by presentation in the first 6 months of life, with subsets of permanent and transient neonatal diabetes mellitus (TNDM) distinguished by spontaneous resolution of hyperglycemia in the latter. Infants with TNDM frequently require hospitalization for rehydration but characteristically do not present with a severe clinical course with ketoacidosis. Here we present a 19-day-old infant with a history of intrauterine growth restriction, small for gestational age, and normal blood sugars in the first 25 hours of life who presented with respiratory distress that rapidly progressed to shock and multiorgan failure. Diagnostic studies on presentation revealed severe hyperglycemia, metabolic acidosis, transaminitis, acute kidney injury, hyperammonemia, and thalamic hyperintensities that collectively raised suspicion for a metabolic/mitochondrial disorder. The patient's clinical course and genetic studies, however, converged on a diagnosis of TNDM due to uniparental disomy of chromosome 6. Diabetes has resolved, but the patient has endured permanent motor deficits associated with thalamic hemorrhage at presentation. This case highlights that TNDM can escape detection by blood glucose measurements in the first days of life and indeed present in severe diabetic ketoacidosis, which can further progress to shock and multiorgan failure that may mimic a metabolic/mitochondrial disorder.