Genetic epilepsy with febrile seizures plus (GEFS+)

Abstract

Febrile seizures (FS) occur in about 2–3% of children aged 3 months to 5 years. Atypical febrile seizures are those with a focal component. Each subsequent febrile attack increases the risk of transformation into epilepsy. After the third febrile seizure, the risk of additional episodes of febrile seizures is already approaching 50%, and the risk of formation of epilepsy is 15.8%. Recent studies show the great contribution of genetic causes to the development of genetic epilepsy with febrile seizures plus (GEFS+). GEFS+ includes a combination of some febrile seizures with subsequent afebrile attack, or recurring febrile seizures after 6 years. The genetic causes of GEFS+ are both monogenic (in particular, disorders in the SCN1B, SCN1A, GABRG2, GABRD, SCN9A, STX1B, HCN1 genes, etc.) and copy number variations. Twin methods suggest that different genetic factors play a role in the case of FS, FS+ and FS with subsequent epilepsy. Genetic cause can be found in about 30% of cases, that affects not only the final diagnosis and prognosis for the patient, but also the prevention of disease in the family. In GEFS+ seizures are usually generalized tonic-clonic, less often myoclonic, myoclonic-atonic seizures, absences and status epilepticus, but sometimes they also describe focal seizures. The clinical picture of patients with GEFS+ varies from family febrile seizures (the least severe cases) to Drave-like syndrome (the most severe cases), although all of them have a predominantly normal level of intellect.