GENETIC EPILEPSY WITH FEBRILE SEIZURES PLUS (GEFS+) SPECTRUM

Overview

Genetic epilepsy with febrile seizures plus spectrum (GEFS+) is a familial syndrome characterized by the presence of febrile seizures in an individual with a family history of seizures/epilepsy. Febrile seizures may be typical febrile seizures or 'febrile seizures plus' (FS+) may occur, where febrile seizures continue past 6 years of age and/or are accompanied by afebrile seizures which may be generalized or focal. FS+ and GEFS+ are distinguished on the basis of family history. A number of dominantly inherited genes have been linked to both GEFS+ and FS+, with implications for specific genetic counselling, due to the variable severity of the epilepsy in different family members. Although febrile seizures are the hallmark of this familial syndrome, not all individuals in a family may have these.

Clinical context

Febrile seizures in this syndrome typically begin between the ages of 6 months and 6 years, they may begin before 6 months of age in some individuals. Febrile seizures are often multiple and and may continue past 6 years of age (FS+). Seizures in FS+ are typically responsive to anti seizure medication (if used), and the epilepsy is self-limiting, remitting by puberty. Afebrile seizures that may be generalized (tonic-clonic, 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. Some individuals in a GEFS+ family may have other epilepsy syndromes e.g. epilepsy with myoclonic atonic seizures or Dravet syndrome, where the seizure types, comorbidities and prognosis are as expected for that syndrome.

NOTE Self-limiting refers to there being a high likelihood of seizures spontaneously remitting at a predictable age.