GRIN2A-related speech disorders and epilepsy are characterized by speech disorders in all affected individuals and a range of epilepsy syndromes present in about 90%. Severe speech disorders observed can include dysarthria and speech dyspraxia, and both receptive and expressive language delay/regression; more mildly affected individuals may display subtly impaired intelligibility of conversational speech. Epilepsy features include seizure onset usually between ages three and six years, focal epilepsy with language and/or global developmental regression, and electroencephalogram (EEG) showing continuous spike-and-wave discharges in sleep or very active centrotemporal discharges. Seizure types include seizures associated with aura of perioral paresthesia, focal or focal motor seizures (often evolving to generalized tonic-clonic), and atypical absence seizures. Epilepsy syndromes can include: Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep (ECSWS), childhood epilepsy with centrotemporal spikes (CECTS), atypical childhood epilepsy with centrotemporal spikes (ACECTS), autosomal dominant rolandic epilepsy with speech dyspraxia (ADRESD), and infantile-onset epileptic encephalopathy.

Benign epilepsy of childhood with centrotemporal spikes (BECTS) or sharp waves, also known as rolandic epilepsy, is the most common idiopathic childhood epilepsy syndrome (Neubauer et al., 1998). It is termed 'rolandic' epilepsy because of the characteristic features of partial seizures involving the region around the lower portion of the central gyrus of Rolando. This results in classic focal seizures that affect the vocal tract, beginning with guttural sounds at the larynx and sensorimotor symptoms that progress to the tongue, mouth, and face, resulting in hypersalivation and speech arrest. Seizures most often occur in sleep shortly before awakening. The disorder occurs more often in boys than in girls (3:2). Rolandic epilepsy is considered a neurodevelopmental disorder, affecting 0.2% of the population. Affected individuals may have learning disabilities or behavioral problems; however, the seizures and accompanying problems usually remit during adolescence (summary by Strug et al., 2009). See also focal epilepsy and speech disorder (FESD; 245570), which is caused by mutation in the GRIN2A gene (138253) on chromosome 16p13. Some patients with GRIN2A mutations show features consistent with a clinical diagnosis of BECTS. Some patients with DEPDC5 (614191) mutations may show features consistent with rolandic epilepsy (see FFEVF, 604364).