GTR Home > Conditions/Phenotypes > Epileptic encephalopathy, early infantile, 1

Summary

Early infantile epileptic encephalopathy is a severe form of epilepsy first reported by Ohtahara et al. (1976). It is characterized by frequent tonic seizures or spasms beginning in infancy with a specific EEG finding of suppression-burst patterns, characterized by high-voltage bursts alternating with almost flat suppression phases. Approximately 75% of EIEE patients progress to 'West syndrome,' which is characterized by tonic spasms with clustering, arrest of psychomotor development, and hypsarrhythmia on EEG (Kato et al., 2007). Deprez et al. (2009) reviewed the genetics of epilepsy syndromes starting in the first year of life and included a diagnostic algorithm. EIEE1 is part of a phenotypic spectrum of disorders caused by mutation in the ARX gene comprising a nearly continuous series of developmental disorders ranging from lissencephaly (LISX2; 300215) to Proud syndrome (300004) to infantile spasms without brain malformations (EIEE1) to syndromic (309510) and nonsyndromic (300419) mental retardation. Although males with ARX mutations are often more severely affected, female mutation carriers may also be affected (Kato et al., 2004; Wallerstein et al., 2008). Genetic Heterogeneity of Early Infantile Epileptic Encephalopathy EIEE is a genetically heterogeneous disorder. See EIEE2 (300672), caused by mutation in the CDKL5 gene (300203); EIEE3 (609304), caused by mutation in the SLC25A22 gene (609302); EIEE4 (612164), caused by mutation in the STXBP1 gene (602926); EIEE5 (613477), caused by mutation in the SPTAN1 gene (182810); EIEE6 (607208), also known as Dravet syndrome, caused by mutation in the SCN1A gene (182389); EIEE7 (613720), caused by mutation in the KCNQ2 gene (602235); EIEE8 (300607), caused by mutation in the ARHGEF9 gene (300429); EIEE9 (300088), caused by mutation in the PCDH19 gene (300460); EIEE10 (613402), caused by mutation in the PNKP gene (605610); EIEE11 (613721), caused by mutation in the SCN2A gene (182390); EIEE12 (613722), caused by mutation in the PLCB1 gene (607120); EIEE13 (614558), caused by mutation in the SCN8A gene (600702); EIEE14 (614959), caused by mutation in the KCNT1 gene (608167); EIEE15 (615006), caused by mutation in the ST3GAL3 gene (606494); EIEE16 (615338), caused by mutation in the TBC1D24 gene (613577); EIEE17 (615473), caused by mutation in the GNAO1 gene (139311); EIEE18 (615476), caused by mutation in the SZT2 gene (615463); EIEE19 (615744), caused by mutation in the GABRA1 gene (137160); EIEE20 (300868), caused by mutation in the PIGA gene (311770); EIEE21 (615833), caused by mutation in the NECAP1 gene (611623); EIEE22 (300896), caused by mutation in the SLC35A2 gene (314375); EIEE23 (615859), caused by mutation in the DOCK7 gene (615730); EIEE24 (615871), caused by mutation in the HCN1 gene (602780); EIEE25 (615905), caused by mutation in the SLC13A5 gene (608305); EIEE26 (616056), caused by mutation in the KCNB1 gene (600397); EIEE27 (616139), caused by mutation in the GRIN2B gene (138252); EIEE28 (616211), caused by mutation in the WWOX gene (605131); EIEE29 (616339), caused by mutation in the AARS gene (601065); EIEE30 (616341), caused by mutation in the SIK1 gene (605705); EIEE31 (616346), caused by mutation in the DNM1 gene (602377); EIEE32 (616366), caused by mutation in the KCNA2 gene (176262); EIEE33 (616409), caused by mutation in the EEF1A2 gene (602959); EIEE34 (616645), caused by mutation in the SLC12A5 gene (606726); EIEE35 (616647), caused by mutation in the ITPA gene (147520); EIEE36 (300884), caused by mutation in the ALG13 gene (300776); EIEE37 (616981), caused by mutation in the FRRS1L gene (604574); EIEE38 (617020), caused by mutation in the ARV1 gene (611647); EIEE39 (612949), caused by mutation in the SLC25A12 gene (603667); EIEE40 (617065), caused by mutation in the GUF1 gene (617064); EIEE41 (617105), caused by mutation in the SLC1A2 gene (600300); EIEE42 (617106), caused by mutation in the CACNA1A gene (601011); EIEE43 (617113), caused by mutation in the GABRB3 gene (137192); EIEE44 (617132), caused by mutation in the UBA5 gene (610552); EIEE45 (617153), caused by mutation in the GABRB1 gene (137190); EIEE46 (617162), caused by mutation in the GRIN2D gene (602717); EIEE47 (617166), caused by mutation in the FGF12 gene (601513); EIEE48 (617276), caused by mutation in the AP3B2 gene (602166); EIEE49 (617281), caused by mutation in the DENND5A gene (617278); EIEE50 (616457) caused by mutation in the CAD gene (114010); EIEE51 (617339), caused by mutation in the MDH2 gene (154100); EIEE52 (617350), caused by mutation in the SCN1B gene (600235); EIEE53 (617389), caused by mutation in the SYNJ1 gene (604297); EIEE54 (617391), caused by mutation in the HNRNPU gene (602869); and EIEE55 (617599), caused by mutation in the PIGP gene (605938). The phenotype is also observed in other genetic disorders, including GLUT1 deficiency syndrome (606777); glycine encephalopathy (605899); Aicardi-Goutieres syndrome (225750); and in males with MECP2 mutations (300673), among others. For associations pending confirmation, see MOLECULAR GENETICS. [from GTR]

Genes See tests for all associated and related genes

  • Also known as: CT121, EIEE1, ISSX, MRX29, MRX32, MRX33, MRX36, MRX38, MRX43, MRX54, MRX76, MRX87, MRXS1, PRTS, ARX
    Summary: aristaless related homeobox

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