Another rare GSK2656157 supplier seizure disorder with an age of onset intermediate between BFNC and BFIC is benign familial neonatal/infantile convulsions (BFNIC). In BFNIC both neonatal and early infantile onsets of the seizures can be present

in the same family. BFNIC has been shown to be caused by mutations in the voltagegated sodium channel subunit gene SCN2A, a gene that is also discussed as a minor gene for generalized epilepsy with febrile seizures plus (GEFS+).23 Febrile seizures, generalized epilepsy with febrile seizures plus, and Dravet syndrome Febrile seizures are the most common seizure Inhibitors,research,lifescience,medical type in humans; they affect 5 % to 10 % of children under the age of 6 years. In most patients an oligo- or polygenic background rather than a monogenic cause of the seizures is assumed. Inhibitors,research,lifescience,medical Rare families with an apparent autosomal dominant mode of inheritance have been identified, and several putative gene loci described. These tentative

gene locations include FEB1 on chromosome 8q13-q21, FEB2 on 19p, FEB3 on 2q23-q24, FEB4 on 5q14-q15, FEB5 on 6q22-q24, and FEB6 on 18p11.2. In some families febrile seizures may persist beyond Inhibitors,research,lifescience,medical the age of 6 years and/or may be associated with variable afebrile seizures (febrile seizures plus). This probably not so rare syndrome has been named generalized epilepsy with febrile seizures plus (GEFS+). Afebrile seizure types in GEFS+ individuals Inhibitors,research,lifescience,medical include generalized tonoclonic seizures, myoclonic, absence, and atonic seizures, and in some patients also partial seizures.24 The mode of inheritance underlying GEFS+ is still a matter of debate. Although in some families the trait is likely to be autosomal dominant, in others it is probably better described as oligogenic or as a major gene effect. A genetic concept involving more than one gene would also

better Inhibitors,research,lifescience,medical fit to the observed clinical variability in GEFS+. Several different ion channel genes have been implicated in GEFS+ – SCN1B, SCN1A, SCN2A, GABRG2 – but in most families the underlying mutation(s) remain elusive. The first GEFS+ mutation was identified in the SCN1B gene on chromosome all 19q13.1, a gene that encodes an accessory subunit of the voltage gated sodium channel.25 Nevertheless, most of the mutations identified since then were found in the SCN1A gene, one of the genes coding for the major, pore-forming α-subunit of the voltage gated sodium channel.25 These α-subunits are composed of four domains each containing sixTM (TM1-TM6), and the SCN1A mutations arc distributed over the whole length of this large gene.