These epilepsy syndromes are characterized by the presence of febrile seizures in an individual that may continue past the usual age where these are expected to resolve and/or be accompanied by afebrile seizures that may be generalized or focal. Febrile seizures plus and genetic epilepsy with febrile seizures plus are distinguished on the basis of family history. A number of dominantly inherited genes have been linked to these syndromes, with implications for specific genetic counseling, due to the variable severity of the resulting epilepsy in different family members.
These syndromes typically have onset with febrile seizures between the ages of 6 months and 6 years. Febrile seizures are often multiple and may continue past 6 years of age, but typically are self-limiting and resolve by puberty. Afebrile seizures that may be generalized (convulsive, atonic, myoclonic, myoclonic-atonic or absence or focal may occur. Both sexes are affected equally. Antecedent and birth history is unremarkable. Head size and neurological examination are normal. Development is typically normal and no developmental impairments are expected.
NOTE Self-limiting refers to there being a high likelihood of seizures spontaneously remitting at a predictable age.