Long-Term Seizure and Neurodevelopmental Outcomes of Three Children with Developmental Delay, Epilepsy, and Neonatal Diabetes (DEND) Syndrome after Early Initiation of Sulphonylurea.

ABSTRACT: Developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome, caused by de novo mutations in ABCC8 / KCNJ11 genes encoding Adenosine Triphosphate (ATP)-sensitive potassium channels, is an unusual cause of infantile-onset developmental/epileptic encephalopathy. Here, we report the long-term seizure and neurodevelopmental outcomes of three children with pathogenic variants in ABCC8 / KCNJ11 genes and the phenotypic spectrum of DEND syndrome. Genetic confirmation was followed by an immediate therapeutic switch from insulin to sulfonylurea in all three children. At the last visit, all these children had good seizure control. However, all of them had residual neurodevelopmental impairments of varying clinical severity. Further large-scale, prospective, multicenter cohorts might be needed to clearly estimate the effect of early initiation of sulphonylurea on long-term seizure and neurodevelopmental outcomes of this rare syndrome.