2 . What is the Cause ?

The cause of Dravet syndrome is considered as genetic. For most of these patients (about 80%), the cause is a mutation in a gene called SCN1A. A mutation in this gene can lead to an abnormal “electrical” brain activity which may trigger seizures.

The diagnosis of Dravet syndrome is based on the clinical story. There is no history of a significant brain injury to explain the epilepsy such as birth asphyxia or meningitis. Standard investigations such as blood biochemistry and brain imaging studies (CT scan and MRI) are normal. In 2001 it became clear that Dravet syndrome is caused by a defect in the electrical function of brain cells.


A small number of patients do not carry a SCN1A mutation. For them, some other mutated genes have already been identified. As for patients who do not carry any of the previously mentioned genes, research is ongoing.

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