Dravet syndrome is a rare, genetic epileptic encephalopathy that gives rise to seizures that don’t respond wellto seizure medications. It begins in the first year of life in an otherwise healthy infant. Before 1989, this syndrome was known as epilepsy with polymorphic seizures, polymorphic epilepsy in infancy (PMEI), or severe myoclonic epilepsy in infancy (SMEI). The disease begins in infancy and is lifelong. Some more important points:

Infants have normal development when seizures begin. Yet as seizures continue, most children develop some level of developmental disability. By later childhood, most children also develop a crouched walk. Diagnosis is often delayed. MRI (magnetic resonance imaging) and EEG (electroencephalogram)tests are ususally normal in infants at first. About 8 out of 10 people with this syndrome have a gene mutation in SCN1A that causes problems in the way ion channels in the brain work. This mutation is most often not inherited from the parents. It is considered a de novo or "new" mutation in the child. Not all SCN1A mutations are associated with Dravet syndrome. These seizures are often long (lasting more than 5 minutes) and can result in status epilepticus(when seizures do not stop or occur close together). Such seizures typically recur every few weeks in infancy and early childhood