Retrospective cohort of Dravet syndrome due to SCN gene mutation from Southern India

Introduction: Dravet syndrome is a genetic epilepsy which begins in early infancy. Initial seizures are often triggered by vaccination or fever. There is lack of adequate data on genotype of Dravet syndrome from Indian subcontinent hence study was planned. Aims and Objectives: To evaluate clinical profile and genotype of SCN mutation positive Dravet syndrome. Methods: Retrospective review of genetically confirmed children with Dravet syndrome at our institute from Jan 2015 to May 2018. Results: Out of twenty-six 18 were male.  All had normal birth and family history. Mean age of presentation was 7.4 months.  Precipitating factor being fever in 18 children, vaccination in 3.  9 children had west syndrome. All had prolonged seizures both focal and generalized type.  18 Patients had hyperactivity and autistic features. Neuroimaging was normal in all patients. Mean age of presentation for abnormal EEG was 16 months.  13 patients had SCN1A mutation, 4 patients with SCN2A, 5 with SCN9A,   1 with SCN1B, 1 with SCN1B+SCN9A, 1 with SCN1A+SCN8A and 1 with SCN1A + SCN9A mutation. Five patients responded to treatment and rest were refractory. Three children were refractory to Stiripentol. Conclusion: Dravet syndrome should be considered with refractory epilepsy with normal birth and development prior to onset of seizures and normal neuro-imaging and EEG in the early part of illness. They can present with infantile spasms in additions to other type of seizures described.