Search for three known mutations in the RYR1 gene in 48 Danish families with malignant hyperthermia.

We have examined 48 Danish families in which malignant hyperthermia reactions have occurred, with respect to three of six published mutations in the gene for the calcium release channel of sarcoplasmic reticulum (the RYR1 gene) believed to cause malignant hyperthermia susceptibility in man. The mutations are Arg614Cys, also known as the "pig mutation"; Arg163Cys; and Ile403Met. The only mutation found was Arg163Cys, which was detected in only one family. The results of this study indicate that other mutations must underlie the disorder in most Danish malignant hyperthermia-susceptible families, and that the "pig mutation" is not a frequent cause of malignant hyperthermia susceptibility in Denmark.