MLPA Technique In The Application Of SCN1A Gene Research In Children With Fever Releated Seizures

BackgroundFebrile seizure is one of the most common neurological disorders, occur in 2-5% of children. There is a strong family history and age-dependent of febrile seizure in siblings and parents. Between 2 and 7% of children who experience febrile seizure go on to develop nonfebrile seizure disorders and epilepsy later in life. In excitable cells, such as central and peripheral neurons,voltage-gated sodium channels are responsible for initiating and propagating action potentials. SCN1A gene is the most relevant gene in clinical features, It located on chromosome 2q24.3.Mutations in the voltage-gated sodium channel subunit gene SCNIA have been associated in 5%-10% children with autosomal dominant generalized epilepsy with febrile seizures plus (GEFS+) families and in 5%-10% children with severe myoclonic epilepsy of infancy. Quantitative MLPA analysis applied to those children with no detectable coding mutations detected between 15and 20% children with unequivocal SCNIA exonic deletions.The same clinical feature between GEFS+ and SMEI is febrile seizure. In previous studies, DHPLC technique and/or direct sequencing applied to those children with febrile seizure detected no child with SCNIA gene. MLPA technique was applied to detect exon deletions or duplications in children with fever related seizures.ObjectiveTo study the clinical features of fever-related seizures and the correlation between Voltage-gated sodium channel alpha 1 subunit gene and fever-related seizures. To study the correlation between Voltage-gated sodium channel alpha 1 subunit gene and febrile seizure related epilepsy syndromes.Methods1.DNA samples were obtained from Qilu hospital of Shandong University, of whom 54 were fever-related seizures.2. MLPA technique was applied to detect exon deletions or duplications in 54 children with fever related seizures and normal coutrol.3.Genetic stratification was undertaken with use of Coffalyser Version 9.4 software. We set thresholds of 0.7 for deletions and 1.3 for duplications. Calculated one by one in 54 cases of 26 exons ratio.ResultsAccording to clinical data and EEG in children, the clinical features of fever-related seizures in children (age, gender, seizure type, onset age, seizure frequency, etc.) were analyzed; 54 cases of fever-related seizure, in which 34 cases of febrile seizure,29 cases of simple febrile seizures,5 cases of complex febrile seizures; epilepsy history of febrile seizures in 20 cases; all children with fever-related seizures were carried SCN1A DNA genetic testing, the Coffalyser Version 9.4 software to compare calculation, the values in between 0.7-1.3, suggesting that 54 cases of fever-related convulsions were not found SCN1A exon deletion or duplication.Conclusions1 Different from the traditional mutation detection methods, as a new gene mutation detection method, MLPA techinique can detect the large fragments deletion or duplication of the gene, large fragments-and it opened up a new idea for the genetics of epilepsy.2. Our study demonstrated that deletions or duplications in SCN1A gene might not be the susceptibility factor for febrile seizure. Together with previous studies, our data suggest that genetic factors other than SCN1A are involved in the etiology of common typical febrile seizure.