The GEFS + (generalized epilepsy with febrile seizures +) syndrome was described in 1997 in a large Australian pedigree and is characterized by the familial occurrence, following an autosomal dominant transmission, of febrile convulsive seizures in infants and young children that may last beyond the age of 6, and that are associated in some with afebrile convulsive seizures and a variety of other seizures types, including typical absences, myoclo-astatic seizures, myoclonias, and focal seizures. The genetic anomalies detected to date imply either Na channels or GABA receptors. In a large French pedigree, we identified 15 patients with the GEFS + syndrome. The index patient was a 15 month-old girl with repeated convulsive febrile, afebrile and atonic seizures, who was fully controlled on valproate. Her neurologic status and development were fully normal, and the interictal EEG did not show any specific abnormality. In this pedigree, all patients had febrile seizures except two who had only afebrile seizures, two had atonic drop attacks, and tonic seizures during sleep and a single secondarily generalized focal hemifacial motor seizure were seen once each. No patient had temporal lobe seizures; they did not have myoclonias nor typical absences. The seizure profile in this family appears to be original, and the existence of yet another type of underlying genetic defect can be suspected.