ABSTRACT
Objective: To study prevalence of SCN1A gene mutations in complex seizure disorders. Methods: Retrospective laboratory based study on samples sent for molecular diagnosis in complex seizure disorders. Exome sequencing was performed. Phenotype- genotype correlation was done for patients showing variants in SCN1A gene. Results: 364 samples were evaluated; of which, 54% were of children below 5 years of age. SCN1A mutations were seen in 50 samples of patients with complex seizure disorders; 44 variants were identified. Types of seizure disorders commonly associated were Dravet syndrome and genetic epilepsy with febrile seizures. Conclusions: SCN1A mutations are common in complex seizure disorders, especially Dravet syndrome. Early identification of SCN1A gene in etiology is important for selection of correct antiepileptic and counselling.