Mutation information:
NumberExon/IntronNucleotide change Protein changeLocation Mutation typeConsequencesPhenotype InheritanceReference
2045c.664C>Tp.Arg222XDIS4NonsenseHaploinsufficiency; LOFSMEIDe novoClaes L.2001
SMEI1De novo;1NANabbout R.2003
SMEINAFukuma G.2004
SMEIDe novoHarkin LA.2007
SMEIDe novoMancardi MM.2006
SMEIDe novoDepienne C.2009
SMEIDe novoOrrico A.2009
SMEI/SMEB2De novo;1NAZuberi SM.2011
IENAWang JW.2012
SMEIDe novoWang JW.2012
SMEDe novoLemke JR.2012
SMEIDe novoWang JW.2012
SMENALee HF.2014
SMENA Xu X.2014


Functional information:
NumberNucleotide changeProtein changeLocationPhenotypeFunctional defect type Details of the major biophysical abnormalities.Reference
4c.664C>Tp.Arg222X(R222X)DIS4SMEILOF Do not generate Na+ current; slow down recovery from fast inactivation.Bechi G.2012


[c.664C>T] Clinical description

No detail description in article. Files of current patients with SMEI at participating centers were reviewed by a panel of experts who selected those who fulfilled the following criteria: no history of acquired brain injury; normal cognitive and motor development before seizure onset; onset of febrile or afebrile seizures, generalized or unilateral, before age one year; myoclonic jerks; intractable epilepsy; psychomotor delay within two years of seizure onset; normal MRI results in the first year of the seizure disorder; and a minimum follow-up of three years.(Nabbout R, et al. Neurology. 2003 Jun 24; 60(12): 1961-7. [12821740])