Genetic mutations in KCNJ11 or ABCC8 which encode Kir6.2 and SUR1 respectively are major causes of insulin secretion disorders: those causing loss of channel function lead to congenital hyperinsulinism, whereas those causing gain of channel function result in neonatal diabetes and in some cases developmental delay, epilepsy, and neonatal diabetes, referred to as the DEND syndrome.
Wide phenotype variability is associated with single ABCC8 mutations, ranging from transient or permanent neonatal diabetes (ND) with or without developmental delay (DEND syndrome) to very mild phenotypes.
We identified a novel heterozygous mutation, F132L, in the ABCC8 gene of a patient with severe developmental delay, epilepsy and neonatal diabetes (DEND syndrome).