Reported between 1:5000 and 1:200 000.
Most affected families have a dominant pattern of inheritance. However, there is a variable penetrance and expressivity of the disease. This occurs on second or later triggering anaesthetic in 1/3 of cases, but all are thought to be picked up by contracture testing.
At least four chromosomal locations have been identified:
Best defined is the Ryanodine receptor on 19q13
Also 17, 7, and 3.