The genetics of seizure disorders, including epilepsy, has recently come into the spotlight (see the Nature Outlook on epilepsy). Epilepsy is a complex disease with many different subtypes, both sporadic and familial. While epilepsy is one of the most common neurological disorders, and it has been studied for a very long time, the underlying mechanisms of seizure disorders remain largely elusive. Identifying the genetic causes of different subtypes of the disorder can help to illuminate the gene networks involved and lead to a deeper understanding overall. Importantly, the genetic tools now exist to identify causal mutations for the many different subtypes of seizure disorders.