Voltage-Gated Channels as Causative Agents for Epilepsies

Lili Long,Xiao Bo,Kun Xia,Mutasem Abuhamed,Yi Fang

doi:10.3844/ajisp.2008.43.50

Abstract

Problem statement: Epilepsy is a common neurological disorder that afflicts 1-2% of the general population worldwide. It encompasses a variety of disorders with seizures. Approach: Idiopathic epilepsies were defined as a heterogeneous group of seizure disorders that show no underlying cause .Voltage-gated ion channels defect were recognized etiology of epilepsy in the central nervous system. The aim of this article was to provide an update on voltage-gated channels and their mutation as causative agents for epilepsies. We described the structures of the voltage-gated channels, discuss their current genetic studies, and then review the effects of voltage-gated channels as causative agents for epilepsies. Results: Channels control the flow of ions in and out of the cell causing depolarization and hyper polarization of the cell. Voltage-gated channels were classified into four types: Sodium, potassium calcium ands chloride. Voltage-gated channels were macromolecular protein complexes within the lipid membrane. They were divided into subunits. Each subunit had a specific function and was encoded by more than one gen. Conclusion: Current genetic studies of idiopathic epilepsies show the importance of genetic influence on Voltage-gated channels. Different genes may regulate a function in a channel; the channel defect was directly responsible for neuronal hyper excitability and seizures.

Highlights

MATERIALS AND METHODSEpilepsy is defined as a group of diseases caused by a non-con-trolled discharge of neurons of either the whole cortex or localized brain areas that show no underlying cause other than a possible inherited predisposition[1]
The genetic basis for two idiopathic epilepsies has been pinpointed to specific ion channel proteins for two different potassium-channel genes (KCNQ2, MIM 602235 and KCNQ3, MIM 602232)[2,3] or sodium channel subunits (SCN2A, OMIM 601219)[4,5,6]
GEFS syndrome is caused by mutation of the at the origin of unbalance between excitation and sodium channel b1 subunit gene located on inhibition and could cause epilepsy

Summary

Introduction

MATERIALS AND METHODSEpilepsy is defined as a group of diseases caused by a non-con-trolled discharge of neurons of either the whole cortex (generalized epilepsies) or localized brain areas (partial epilepsies) that show no underlying cause other than a possible inherited predisposition[1]. The genetic basis for two idiopathic epilepsies has been pinpointed to specific ion channel proteins for two different potassium-channel genes (KCNQ2, MIM 602235 and KCNQ3, MIM 602232)[2,3] or sodium channel subunits (SCN2A, OMIM 601219)[4,5,6].

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Conclusion