MANY CAUSES OF EPILEPSY ARE RARE Although epilepsy as a diagnosis is not rare, many causes of epilepsy are rare. When the underlying cause of epilepsy impacts fewer than 200,000, it is considered a rare epilepsy. At least 100 genes are known to cause epilepsy, not to mention other structural, metabolic, immune, and infectious causes of rare epilepsies. Moreover, 1,000 genetic disorders have epilepsy as a common symptom. Most if not all of these are also rare. Rare epilepsies