Prognostic, Clinical, and Demographic Features in SCN1A Mutation-positive Dravet Syndrome

Dravet syndrome typically manifests after the first year of life with prolonged febrile and afebrile seizures in previously developmentally normal children. The epilepsy is often refractory to standard anti-seizure medications, and by age two, most children develop epileptic encephalopathy. This retrospective study aimed to identify predictors of treatment response and developmental outcomes, as well as characterise demographic and clinical features in patients with SCN1A mutations. We reviewed clinical records of patients meeting Dravet syndrome diagnostic criteria, extracting data on demographics, clinical phenotype, and treatment history. Seventeen patients were included (male-to-female ratio 0.54:1; mean age 10.03 ± 5.8 years). All had normal birth histories, and 94.1% experienced their first seizure before six months of age, with fever as the precipitating factor in 70.6%. All patients had a history of prolonged seizures or status epilepticus. Initial interictal EEGs were normal in 76.5% during the first two years, and brain MRI was normal in 88.2%. While all children were developmentally normal before seizure onset, 76.5% later exhibited developmental delay and cognitive decline. Seizures worsened in 52.9% of patients when treated with phenobarbital, carbamazepine, lamotrigine, or vigabatrin (as mono- or polytherapy). After genetic confirmation, 94.1% received a combination of stiripentol, valproate, and clobazam, resulting in >50% seizure reduction in 88.2%. Dravet syndrome should be considered in children with refractory epilepsy, infantile-onset recurrent seizures (including febrile seizures/status epilepticus), and normal early development. Genetic testing enables early diagnosis and guides appropriate treatment, improving outcomes. However, no statistically significant predictors of treatment response or developmental outcomes were identified in this cohort