Mutation information:
NumberExon/IntronNucleotide change Protein changeLocation Mutation typeConsequencesPhenotype InheritanceReference
115321c.4219C>Tp.Arg1407XDIIIS5-S6NonsenseHaploinsufficiency;LOFSMEIDe novoSugawara T.2002
SMEINAFukuma G.2004
SMEIDe novoHarkin LA.2007
SMEINAWang JW.2012

Functional information:
NumberNucleotide changeProtein changeLocationPhenotypeFunctional defect type Details of the major biophysical abnormalities.Reference
32c.4219C>Tp.Arg1407X (R1396X)DIIIS5-S6SMEILOFExtremely small Na+ currents, generate non-functional channel.Sugawara T.2003

[c.4219C>T] Clinical description

The first seizure of the male patient, three-years-old, was presented with hemiclonic seizures at the age of four months. Thereafter the patient occurred other seizures including absence seizures from eight months of age, myoclonia seizures with daily from 6months of age, GTCS with weekly from eight months of age, and complex partial seizures with  monthly from one year of age. The patient had  ataxia and 50 of developmental quotient. The patient's mother had febrile convulsion. The CT and MRI scan was normal, and the electroencephalogram analysis showed  spike-wave complex, poly spike-wave complex, and photosensitivity(Sugawara T,et al. Neurology. 2002 Apr 9;58(7): 1122-4. [11940708]).