Voltage-gated ion channelopathies of the nervous system

Mutations in genes coding for voltage-gated ion channels cause a diverse group of disorders affecting heart, skeletal muscle, and brain. Mutant channels alter the electrical excitability of cells, which increases the susceptibility to paroxysmal symptoms including cardiac arrhythmia, periodic paralysis, myotonia, seizures, migraine headache, and episodic ataxia. This review provides an update on the genetics and physiology of diseases of skeletal muscle and brain caused by mutations in voltage-gated in ion channel genes. The discovery of specific ion channel defects provides a rational basis for designing pharmacological intervention, as ion channels are the molecular targets of many drugs in clinical use. Moreover, the advent of a molecular genetic-based diagnosis provides an important tool for clarifying the natural history and effectiveness of intervention in these disorders.