Improved motor development and good long-term glycaemic control with sulfonylurea treatment in a patient with the syndrome of intermediate developmental delay, early-onset generalised epilepsy and neonatal diabetes associated with the V59M mutation in the KCNJ11 gene

Aims/hypothesis Activating mutations in the KCNJ11 gene encoding the Kir6.2 subunit of the KATP channels in pancreatic beta cells are a common cause of neonatal diabetes. One-third of patients also have developmental delay, which probably results from mutated KATP channels in muscle, nerve and brain. Sulfonylureas, which bind to the sulfonylurea receptor 1 subunit of the KATP channel, can replace insulin injections in patients with KCNJ11 mutations. The aim of this study was to investigate the long-term outcome and impact on neurological features of sulfonylurea treatment.