AB081. Acute encephalopathy in Dravet syndrome: two case reports and discussion of risk factors

Background: Acute encephalopathy has been sporadically reported in patients with Dravet syndrome. However, risk factors for this important complication in Dravet syndrome are not clear yet.

Methods: We describe two patients who had clinical diagnosis of Dravet syndrome and experienced acute encephalopathy initiated by refractory status epilepticus.

Results: SCN1A mutational analysis by direct sequencing and multiplex ligation-dependent probe amplification revealed a previously reported de novo heterozygous nonsense mutation in one patient and a novel de novo homozygous missense mutation in the other. The analysis of clinical features of our cases and previously published cases showed that an earlier age of onset (6 months of age or less) and a more typical phenotype of Dravet syndrome, including the presence of myoclonic seizures and status epilepticus, are possible phenotypic risk factors for Dravet syndrome patients to complicate acute encephalopathy.

Conclusions: We have identified, for the first time, a de novo homozygous missense mutation in SCN1A gene. We also review literature and discuss some possible phenotypic risk factors for patients with Dravet syndrome to develop acute encephalopathy.

Keywords: Dravet syndrome; acute encephalopathy; Vietnamese