|Number||Nucleotide change||Protein change||Location||Phenotype||Functional defect type||Details of the major biophysical abnormalities.||Reference|
|34||c.4723C>T||p.Arg1575Cys(R1575C)||DIVS2||Rasmussen encephalitis f||GOF||Exhibited increased channel availability and an increased persistent sodium current in comparison to the wild-type.||Ohmori I.2008|
|Number||Nucleotide change||Protein change||Mutation type||Proband's phenotype||1st transmitter's phenotype||Mosaic||Affected generations||Penetrance||Reference|
|125||c.4723C>T||p.Arg1575Cys(DIVS2)||Missense||SMEI||No symptom(Maternal)||2||1/2||Depienne C.2009|
|Rasmussen||No symptom(Paternal)||2||Ohmori I.2008|
|AERRPS||No symptom(Paternal)||Kobayashi K.2010|
|SMEB||No symptom(Maternal)||Lim BC.2011|
|[c.4723C>T] Clinical description|
The patient was a 10-year-old girl and her representative clinical data are shown in article. She had febrile seizures at one year one month of age and one year seven months of age. In the initial prodromal phase, her development and EEG were both age appropriate. Afebrile generalized tonic-clonic seizures (GTCS) began to occur weekly at two years of age. Her mental development delayed thereafter. Spikes were found in the left frontal region on EEG and valproate was started. She had varicella at two years five months of age. She has suffered from myoclonic seizures since two years six months of age. Her EEG showed many spike-wave complexes. A battery of examinations, including MRI, CT, SPECT with 99mTc-ECD , CSF, and analyses of chromosome, urinary organic acids, and lysosomal enzymes, were all normal. Regarding the family history, a febrile seizure occurred in her paternal aunt and one of her maternal cousins, respectively. The administration of clonazepam suppressed the myoclonic seizures and potassium bromide reduced the GTCS. At five years of age, she had idiopathic thrombocytopenic purpura (ITP). She frequently had focal motor seizures with asymmetric tonic posture. She had a mild gait abnormality with less movement in the right arm than in the left at around five years of age. At eight years of age, right hemiparesis was evident. EEG showed asymmetric slowing in the left hemisphere and a cerebral atrophy of the left hemisphere was found in MRI. She was suspected to have rasmussen encephalitis, so autoantibodies against GluR2 and GluR3 in the serum were analyzed using ELISA. Autoantibodies against GluR3 were detected. Her condition has since deteriorated and her IQ (Tanaka-Binet) was 29 at nine years of age. SPECT showed hypoperfusion in the left temporoparietal lobes(Ohmori I, et al. Epilepsia. 2008 Mar;49(3):521-6. ).
Copyright ©2014 Institute of Neuroscience and The Second Affiliated Hospital of Guangzhou Medical University
Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China
Collaborative Innovation Center for Neurogenetics and Channelopathies, Guangzhou 510260, China.