EMHG guidelines for the investigation of MH susceptibility

Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic disease triggered by commonly used volatile anaesthetics and/or succinylcholine. In vitro muscle contracture testing (IVCT) is the gold standard test to establish an individual's risk of MH susceptibility. The European MH Group has elaborated a standardized protocol for IVCT and has initiated international collaborative molecular genetic studies to investigate the molecular basis of MH. Data from these studies demonstrate that MH has a high level of locus heterogeneity. It is important to avoid false MH negative (MHN) diagnoses because of the potential risk of MH during general anaesthesia for these patients and their offspring. The diagnostic guidelines are regularly updated by the European MH Group and published on this website.

The usual route of entry for individuals into MH investigations follows a suspected MH crisis and referral of the patient to an MH Investigation Unit. The diagnostic procedures and genetic counselling are performed according to current knowledge.


  1. Denborough M. Malignant hyperthermia. Lancet 1998; 352: 1131-36.

  2. European MH Group. A protocol for the investigation of malignant hyperpyrexia (MH) susceptibility. Br J Anaesth 1984; 56: 1267-9.

  3. Ording H for the European Malignant Hyperthermia Group. In vitro contracture test for the diagnosis of malingant hyperthermia following the protocol of the European MH Group: Results of testing patients surviving fulminant MH and unrelated low-risk subjects. Acta Anaesthesiol Scand 1997; 41: 955-66.

  4. Urwyler A, Deufel T, McCarthy T, West S for the European Malignant Hyperthermia Group. Guidelines for molecular genetic detection of susceptibility to malignant hyperthermia. Br J Anaesth 2001; 86: 283-7.

  5. P. M. Hopkins; H. Ruffert; M. M. Snoeck; T. Girard; K. P. E. Glahn; F. R. Ellis; C. R. Muller; A. Urwyler, on behalf of The European Malignant Hyperthermia Group; British Journal of Anaesthesia 2015; 115(4):531-9

Investigation of MH Susceptibility

In 2015 the EMHG has published a revision of the guidelines for the investigation of MH susceptibility. This version of the guidelines now combines previous guidelines on in-vitro contracture testing and molecular genetic investigations.

Characterisation of RYR1 sequence variants

Guidelines on characterisation of RYR1 variants in order to be used diagnostically to test for MH susceptibility

Gene variants as unlikely to cause MH Susceptibility

Criteria for the determination of gene variants as unlikely to cause malignant hyperthermia susceptibility