Inherited epilepsies caused by defects in Na+ channel genes and (GABA) A receptor genes

Abstract

Channelopathies are defined as inherited diseases, mostly located in an autosomal dominant gene. This review describes the significant number of new gene associated with genetic epilepsy syndromes that have emerged during the last decade, together with additional mutations relating to previously known gene associations. RECENT FINDINGS: Examples of ion channels most often associated with epilepsy are: A sodium channel, alpha1 subunit (SCN1A) defect was predominantly associated to generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI). A mutation in GABA Receptor Gene, Gamma 2 subunit (GABRG2) is linked with childhood absence epilepsy with febrile seizures plus (FS+). Autosomal dominant form of juvenile myoclonic epilepsy was demonstrated to be a channelopathy associated with a mutation in GABA (A) receptor, alpha1 subunit (GABRA1). Additional effects of genetic variation, even within the same ion channel gene families, are likely to underlie the common idiopathic generalized epilepsies with complex inheritance. The genetic epilepsy is fast progressing toward a more detailed molecular dissection and definition of syndromes.