Generalized epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which family members display a seizure disorder from the GEFS+ spectrum which ranges from simple febrile seizures (FS) to the more severe phenotype of myoclonic-astatic epilepsy (MAE) or Dravet syndrome (DS). Mutations in the SCN9A gene cause a spectrum of seizure disorders, ranging from early-onset isolated febrile seizures to generalized epilepsy with febrile seizures plus, type 7, which represents a more severe phenotype. [From Orphanet and OMIM]