The UK prevalence of MH has been estimated to be between 1 in 8,000 - 10,000. MH is genetically heterogeneous but the majority (80%) of UK families show linkage to the ryanodine receptor gene (RYR1) on chromosome 19q12.1-13.2 whichencodes a voltage-gated skeletal muscle Ca2+ releasechannel. Mutations have also been identified in the alpha 1 subunit of the voltage-gated calcium channel gene (CACNA1S).To date more than 100 RYR1 mutations have been identified in association with MH and/or central core disease (CCD), the majority missense. Due to the genetic heterogeneity of the disorder, guidelines for genetic diagnosis have been established by the European MH Group, in conjunction with the established in vitro contracture test (IVCT) carried out on live muscle biopsy specimens. To date, 30 missense mutations (RYR1 and CACNA1S), where in vitro functional analysis has indicated an alteration in normal function, are considered causative.

MH Research is needed to develop a less invasive test that is more widely available; to discover why MH presents only sometimes with triggered anesthetics; to find out why some MH patients are susceptible to heat and exercise, and why they react to non-anesthetic triggers. Donations help MH experts answer these questions through research and discovery. Link to article.