Early clinical features of Dravet syndrome with SCN1A mutation

Abstract

Objective To summarize the early clinical characteristics and diagnosis of patients with Dravet syndrome (DS). Methods The clinical data and peripheral blood DNA of DS patients and their parents were colle-cted.The features of seizures in 187 DS patients with SCN1A gene mutation were analyzed before the age of 1. Results Of the 187 DS patients, 103 were male, and 84 were female.The age at the first seizure ranged from 2 to 12 months (median: 6 months). One hurdred and thirty-eight (73.8%, 138/187 cases) of them experienced the first attack younger than 7 months after birth, 71.7% (134/187 cases) of the patients were identified febrile seizure duration more than 15 min, 47.6% (89/187 cases) of them suffering from attacks lasting more than 30 min, 124 patients (66.3%, 124/187 cass)were observed 2 or more seizures induced by fever within 24 hours, and 156 patients (83.4%, 156/187 cases) were identified with hemi-clonic and/or focal seizures.Among the 3 features of complex febrile seizure, 2 items were discovered in 41.2%(77/187 cases) patients and 3 items in 41.2%(77/187 cases). Seizures had been triggered by fever of low degree (<38 ℃) in 65.2%(122/187 cases) patients before the first year of life.Fifty-seven (30.5%, 57/187 cases) patients had the vaccine-related seizures.Fifty-nine (31.6%, 59/187 cases) patients had attacks without fever before the age of 1. Conclusions The seizure onset age in DS patients is earlier than that in common febrile seizures.When a baby conforms to 2 or more features of complex febrile seizures, the diagnosis of DS was very likely considered, and SCN1A gene mutation screening should be done as early as possible.Early diagnosis of DS can help to choose appropriate antiepileptic drugs for the patients. Key words: Dravet syndrome; SCN1A gene; Mutation; Febrile seizures; Diagnosis