Physiologic principles underlying ion channelopathies

The ion channelopathies are a diverse array of human disorders caused by mutations in genes coding for ion channels. More than 40 different channelopathies have been identified, with representative disorders from every major class of ion channel and affecting all electrically excitable tissues: brain, peripheral nerve, skeletal muscle, smooth muscle, and heart. This review provides an overview of ion channel classi-fication, structure, and function as a framework for understanding which ion channel properties are altered by disease-associated mutations and how these changes disrupt cellular excitability for channelopathies affecting skeletal muscle and the CNS.