Mutation information:
NumberExon/IntronNucleotide change Protein changeLocation Mutation typeConsequencesPhenotype InheritanceReference
57812c.2134C>Tp.Arg712XDI-DIINonsenseHaploinsufficiency;LOFSMEINASugawara T.2002
SMEIDe novoOhmori I.2002
SMEIFamilial(Maternal,mosaic,asympt),P=1/1Depienne C.2009,2010
SMEI2De novo;2NA Depienne C.2009,2010
SMEI1De novo;1NAFukuma G.2004
SMEI/Unclassified2De novo;3NAZuberi SM.2011
SMEIDe novoWang JW.2012
IENAWang JW.2012
SMEIDe novoWang JW.2012
SMEINAWang JW.2012
SME+AENAOkumura A.2012
SMENAMoehring J.2013
SMENALee HF.2014
SMENAXu X.2014


Functional information:
NumberNucleotide changeProtein changeLocationPhenotypeFunctional defect type Details of the major biophysical abnormalities.Reference
10c.2134C>Tp.Arg712X(R712X)DI-DII (D-linkers)SMEILOFExtremely small Na+ currents, generate non-functional channel.Sugawara T.2003


Inheritance information:
NumberNucleotide changeProtein changeMutation type Proband's phenotype1st transmitter's phenotype Mosaic Affected generationsPenetranceReference
41c.2134C>Tp.Arg712X(DI-DII)NonsenseSMEINo symptom(Maternal)Mosaic(~23%)21/1Depienne C.2010


[c.2134C>T] Clinical description

The first seizure of the male patient, 24-years-old, was presented with generalized tonic clonic seizures at the age of seven months. Thereafter the patient occurred other seizures including absence seizures from three years old, myoclonia from three to seven years old, and generalized tonic clonic seizures with yearly. The patient had severe mental decline and ataxia. The patient's paternal aunt had febrile convulsionre. The CT was normal. The electroencephalogram analysis showed poly spike-wave complex, sharp waves in frontal region(Sugawara T,et al. Neurology. 2002 Apr 9;58(7): 1122-4. [11940708]).