An MH reaction is a rare event, occurring in about one in every ten thousand general anaesthetics. Probably at least one person in every five thousand in the population is potentially susceptible.
Triggering anaesthetics do not necessarily cause an MH crisis every time someone at risk is given them. MH is hereditary; it is passed on through the family. It affects males and females equally, and can occur in every ethnicity. A person with MH has a 50% chance of passing that risk on to each child that they have.
The new Malignant Hyperthermia Australia & New Zealand website provides information for anaesthetists and patients, as well as an online training program and referral contacts.