Diseases caused by mutations in SCN1A are currently named Genetic Epilepsies with Febrile Seizures Plus, and this term stands for expanded spectrum of syndrome previously called as GEFS+ (Generalized Epilepsy with Febrile Seizures Plus). SCN1A is the uniquely identified gene directly linked to specific type of epilepsy, and its testing has been included in the screening processes.
The aim: To diagnose and describe epileptic syndromes caused by SCN1A mutations.
Material and methods: 203 patients were included in the screening process with suspected SCN1A mutation, based on clinical features and family history. Study group was selected based on inclusion and exclusion criteria and then preliminary epilepsy diagnosis was verified using ILAE classification. Molecular testing to screen SCN1A mutations was performed in the study group.
Results: Mutations were detected in 57 cases. Majority of patients (50 cases - 87.5%) suffered from Dravet syndrome, 8.8% (5 cases) were diagnosed as GEFS+, 3% as vaccines encephalopathy and Panayotopoulous syndrome. Mutations were not detected in children with isolated febrile seizures, family febrile seizures nor in patients with myoclonic - astatic epilepsy.
Conclusions: Frequency of mutations in SCN1A in Dravet syndrome and GEFS+ in Polish populations are similar to other countries. Diagnostic clinical criteria are currently insufficient to draw precise diagnosis. There is a strong need to establish clinical criteria for molecular testing and this topic will be investigated in the future.