Identification of First Case of Neonatal Diabetes in Singapore and Successful Conversion from Insulin to Sulphonylurea

Abstract

Introduction: To date Neonatal Diabetes Mellitus (NDM) has not been reported in Singapore. Neonatal diabetes is a rare (1 in 100,00–300,000 live births) insulin-requiring form of diabetes with well defined subgroups, permanent neonatal diabetes (PND) and transient neonatal diabetes (TND), each accounting for approximately 50% of patients. Genotyping NDM identifies the exact unique molecular aetiology of very early onset insulin requiring diabetes and has the potential to dramatically alter the management of the patient, who would otherwise be insulin dependent for life. Method: We identified a child who presented at 3 and half months of age with diabetic ketoacidosis and determined the phenotypic and genotypic characteristics. Blood samples for molecular genetic analysis were sent to Royal Devon and Exeter Foundation Trust, UK. We determined her Continuous Glucose Monitoring profiles after initiation of sulphonylurea therapy. Results: The patient was diagnosed as a heterozygous for a missense mutation R201H, in the KCNJ11 gene. Results confirmed a diagnosis of permanent neonatal diabetes due to a mutation in the Kir6.2 subunit of the K ATP channel. We initiated sulphonylurea therapy and subsequently ceased insulin treatment successfully. Currently 2 years old, this patient is no longer insulin dependent. Conclusion: This is the first case report of neonatal diabetes in Singapore. It describes the importance of correct identification of the case, and successful conversion of therapy from insulin to sulphonylureas with optimal blood glucose control. We emphasise the need for medical practitioners to consider molecular testing for all patients who present with diabetes below 6 months of age as this will facilitate accurate diagnosis and appropriate therapy.