Genes of Early-Onset Epileptic Encephalopathies: From Genotype to Phenotype

Early-onset epileptic encephalopathies are severe disorders in which cognitive, sensory, and motor development is impaired by recurrent clinical seizures or prominent interictal epileptiform discharges during the neonatal or early infantile periods. They include Ohtahara syndrome, early myoclonic epileptic encephalopathy, West syndrome, Dravet syndrome, and other diseases, e.g., X-linked myoclonic seizures, spasticity and intellectual disability syndrome, idiopathic infantile epileptic-dyskinetic encephalopathy, epilepsy and mental retardation limited to females, and severe infantile multifocal epilepsy. We summarize recent updates on the genes and related clinical syndromes involved in the pathogenesis of early-onset epileptic encephalopathies: Aristaless-related homeobox (ARX), cyclin-dependent kinase-like 5 (CDKL5), syntaxin-binding protein 1 (S7XBP1), solute carrier family 25 member 22 (SLC25A22), nonerythrocytic alpha-spectrin-1 (SPTAN1), phospholipase C beta 1 (PLC beta 1), membrane-associated guanylate kinase inverted-2 (MAG12), polynucleotide kinase 3'-phosphatase (PNKP), sodium channel neuronal type 1 alpha subunit (SCN1A), protocadherin 19 (PCDH19), and pyridoxamine 5-prime-phosphate oxidase (PNPO). (C) 2012 Published by Elsevier Inc.