KCTD7 (potassium channel tetramerization domain containing 7) is a protein with unknown function that is defective in progressive myoclonic epilepsy-3 (EPM3), neuronal ceroid lipofuscinosis 14 (CLN14), and opsoclonus-myoclonus syndrome (OMS)26–28. Here, KCTD7 is linked to opsoclonus-myoclonus syndrome.