Neonatal diabetes melittus due to a rare mutation in KCNJ11 GENE

Sunil Kumar, Anuj Thakur
Department of Pediatrics, Kalpana Chawla Government Medical College, India
Department of Neonatology, Thakur Hospital, India

Neonatal diabetes is a heterogeneous group of rare monogenic disorders with an incidence of about 1 in 100,000 live births presenting within the first six months of life with polyuria, dehydration, and ketoacidosis. We hereby present a case of neonatal diabetes mellitus due to a very rare mutation (reported first time from Indian population) affecting the KCNJ11 gene encoding for KIR6.2 subunit of KATP channels resulting in inhibition of insulin release and hyperglycemia leading to permanent neonatal diabetes for which sulfonylurea are the preferred treatment instead of insulin injection as endogenous insulin synthesis is not affected unlike other causes of permanent neonatal diabetes mellitus affecting insulin synthesis for which insulin is the only treatment.

Neonatal diabetes mellitus (NDM) is defined as insulin-requiring persistent hypergly¬cemia occurring in the first 6 months of life. It is categorized into permanent neonatal diabetes and transient neonatal diabetes. Heterozygous activating mutations in the KCNJ11 and ABCC8 genes which encode the Kir 6.2 and SUR1 subunits of the ATP-sensitive potassium (KATP) channels that control insulin secretion are the commonest and a rarer cause of permanent neonatal diabetes respectively. It is vital to recognize KATP channel mutation as most of these patients don’t require insulin injections and achieve better glycemic control with sulphonylureas as in the current case.

We describe one such of case neonatal diabetes mellitus due to a rare KCNJ11 mutation.