Low-dose fenfluramine as an effective treatment option for ‘atypical’ Dravet syndrome

• Dravet syndrome (DS) is diagnosed based on the clinical course and genetic testing. • Low-dose fenfluramine (FFA) is an effective treatment for typical and atypical DS. • FFA caused no serious adverse events in the present case of atypical DS. Dravet syndrome (DS) is characterized by recurrent convulsive seizures, including status epilepticus, and intellectual disability as a comorbidity. Seizures associated with DS are commonly resistant to antiseizure medications. Typical features of DS are recurrent episodes of status epilepticus, the presence of genetic mutations, and no abnormal magnetic resonance imaging (MRI) findings. Here, we report a rare case of DS in a 14-year-old girl who was negative for genetic mutations, had experienced status epilepticus only once, and had abnormal findings on brain MRI. Although our patient’s case features are atypical of DS, they do not contradict the diagnostic criteria. Despite the difficulty in diagnosing DS because of the negative genetic testing results, we started our patient on fenfluramine (FFA). Long-term treatment with low-dose FFA effectively controlled our patient’s seizures and resulted in cognitive and functional improvements.