Generalized epilepsy with febrile seizure plus (GEFS+)
Incidence
GEFS+ is transmitted as an autosomal dominant trait with incomplete penetrance (70-80%) and is associated with genetic heterogeneity. Its prevalence is not yet established.
Clinical Characteristics
Generalized epilepsy with febrile seizures-plus context (GEFS+) refers to a rare heterogeneous familial condition, which has been recently described. Its prevalence is not yet established. Patients affected with GEFS+ display febrile seizures persisting sometimes beyond the age of 6 years and/or a variety of afebrile seizure types. It is considered an epileptic syndrome. Disease course and response to antiepileptic treatment show an important intrafamilial variation: in some patients, afebrile seizures may either occur rarely or disappear after some years of disease evolution, whereas epilepsy is severe and pharmacoresistant in other members of the same family. In family members with epileptic seizures they almost always start with febrile convulsions (seizures associated with high temperature). Normally febrile convulsions stop after the age of six. In GEFS+ families, children may go on to have febrile seizures well beyond this age group or develop other seizure types not associated with fever. Very rarely there may be a family member with a very severe type of epilepsy called Dravet’s syndrome (severe myoclonic epilepsy of infancy or SMEI). The majority of GEFS+ patients have normal intelligence and learning abilities, however those with myoclonic astatic epilepsy and particularly Dravet’s syndrome may have varying degrees of learning difficulties and behavioural problems. GEFS+ is transmitted as an autosomal dominant trait with incomplete penetrance (70-80%) and is associated with genetic heterogeneity. GEFS+ belongs to the group of channelopathies, as it is associated with mutations in genes encoding different subunits of the neuronal voltage-gated sodium channel and the gamma-2 subunit of the GABAA receptor.
Precipitants
Lack of sleep, fever and withdrawal of treatment may trigger an attack
Provocation Tests
None specifically.
Diagnostic Procedures
It is a clinical diagnosis. GEFS+ is usually identified when the doctor takes a careful family history from a patient presenting with febrile seizures outside the normal age range.