Mutations in GRIN2A haverecently been detected in idiopathic focal epilepsy with rolandic spikes and related epilepticencephalopathies, that is, in Landau–Kleffner syndrome, epilepsy with continuousspike-and-waves during slow sleep syndrome, and nonsyndromic epilepsy associated with intellectualdisability (ID).8–11 By contrast, GRIN2B has not been described as an epilepsy gene to datebut has repeatedly been considered as a putative candidate gene for seizures,8,12 and mutations were detected in patientswith ID, autism spectrum disorders (ASD), and schizophrenia.8,13–18. Here, GRIN2A is linked to epilepsy.