Current views of the molecular basis of the malignant hyperthermia syndrome.

The muscle disease malignant hyperthermia is a disorder of intracellular free Ca2+ regulation in both humans and pigs. Current evidence indicates that the Ca2+ channel of the sarcoplasmic reticulum of MH muscle is abnormally sensitive to Ca2+ and to halothane. Mitochondria, the sarcolemma and the transverse tubule appear not to be involved in primary pathogenesis of MH. Molecular genetic studies indicate that the MH gene is on human chromosome 19 and that the likely candidate gene is that coding for the Ca2+ channel.