Sequence analysis of common gene mutation for neonatal diabetes: Three case series report of neonates with severe neonatal hyperglycaemia

Abstract

Neonatal diabetes mellitus (NDM) is a rare disorder characterized by persistent hyperglycaemia within the first six months of life, resulting from inadequate insulin production, hence the need for exogenous insulin therapy. This persistent hyperglycaemia can be life‑threatening and often associated with adverse consequences if undiagnosed. Hence, the need for high index of suspicion, prompt investigation and early diagnosis, in an attempt to provide appropriate and cost-effective therapy. We report three cases of infants that presented with persistent hyperglycaemia and were managed for neonatal diabetes. The infants had their blood glucose done at presentation using a glucometer (Accu‑chek Active® Roche Diagnostics GmbH, Germany). Blood samples for the genetic test were aseptically taken from each infant and inoculated into EDTA bottles, stored in a refrigerator, and later transported within 24hrs through courier service in an ice pack flask to the molecular genetics’ laboratory at the University of Exeter, United Kingdom, for genetic studies for KCNJ11, ABCC8, and INS genes. The three babies had clinical features of neonatal diabetes and received insulin therapy as part of management; however, the genetic analysis did not identify any mutation. Newborn babies can present with hyperglycaemia from varied causes, of which NDM, though rare, is one of them. We recommend early investigation of the cause of hyperglycaemia, and in the exclusion of common causes, extensive genetic studies including other implicated genes such as FOXP3, GLUT2, and IPF1, should be considered.