Screening SCN3A Gene In Mentally Retarded Patients Of Epilepsy With Febrile Seizures Plus

Purpose To explore the possible relationship between the SCN3A gene with epilepsy with febrile seizures plus.We screen the SCN3A gene exons to search the mutational sites in 15 patients. The result can provide reference to the further function study, clinical gene diagnosis and therapy.Methods Study was done in 6379 patients with epilepsy visiting our epileptic clinic during 2004-2008. According to criteria of the International League against Epilepsy (ILAE), FS, SMEI were diagnosed; according to international criteria, GEFS+, SMEB were diagnosed; and the diagnosis of PEFS+ was made based on the partial seizures. And the information of clinical manifestation, EEG, brain imaging, psychiatric development, treatment and prognosis were also collected and analyzed. DNA of these patients were extracted from peripheral blood, then amplified in vitro the 26 coding exons of SCN3A using PCR. Followed by screening and sequence analysis. The novel mutational sites were verified by setting up the neurological normal controls(80 cases).Results 15 patients were collected,which diagnostic classification including SME,GEFS+,PEFS+ and FS. All patients had multiple seizure types, generalized seizures included tonic-clonic, myoclonic, absence, tonic seizures. Parital seizures included CPS, sGTCS, SPS and unilateral clonic seizures. All the patients had different degrees of mental developing retardation, some had abnormality on brain imaging. Two novel coding variant were found by sequence analysis. Missence coding variant c.1388C>T(p.A463V) was identified in patient PD53. Missence coding variant c.3282C>A(p.D998E) was identified in patient 51, and his father had the same mutation. Two novel coding variants were not present in 50 neurological normal controls.Conclusions SCN3A mutations might contribute to epilepsy with FS plus. It is necessary to screen SCN3A exons in mentally retarded patients of epilepsy with Febrile seizures plus.