Mutations in RYR1 gene, which causes abnormalities in the opening probability of the Ca2+ channel, are also often associated to malignant hyperthermia (MH) susceptibility, an inherited pharmacogenetic subclinical myopathy, characterized by a life-threatening hypermetabolic response to commonly used halogenated/volatile anesthetics (i.e., halothane, isofluorane) [8, 9]. This evidence concerns the gene RYR1 and Malignant hyperthermia.