Early Infantile Epileptic Encephalopathy (EIEE) Panel

Early Infantile Epileptic Encephalopathy (EIEE) Panel

Early infantile epileptic encephalopathy (EIEE), also known as Ohtahara syndrome, is a severe form of epilepsy characterized by frequent tonic spasms with onset in the first months of life.  EEG reveals suppression-burst patterns, characterized by high-voltage bursts alternating with almost flat suppression phases. Seizures are medically intractable with evolution to West syndrome at 3-6 months of age and then Lennox-Gastaut syndrome at 1-3 years of age.  EIEE represents approximately 1% of all epilepsies occuring in children less than 15 years of age.  Patients have severe developmental delay and poor prognosis.  The diagnostic workup of EIEEs remains challenging because of frequent difficulties in defining etiologies.  Acquired structural abnormalities like hypoxic-ischemic insults and isolated cortical malformations, which represent the most common causes of epileptic encelphalopathy in infancy should be excluded first.  Our EIEE panel includes full gene sequencing and deletion/duplication analysis of ARX, CDKL5, SLC25A22, STXBP1, SPTAN1, SCN1A, ARHGEF9, PCDH19, PNKP, SLC2A1, GRIN2A, and MAGI2, and sequence analysis of KCNQ2, PLCB1 and SCN2A.  Mutations in these genes have been described in individuals with an EIEE phenotype.