20 Years of Malignant Hyperthermia in Czechia and Slovakia

Objective: The aim of this publication was to describe the occurrence of malignant hyperthermia (MH) in the Czech and Slovak populations, including genetic results and reasons for reporting to the MH diagnostic centre.Design: Retrospective observational cohort study.Setting: Academic Centre of Malignant Hyperthermia of Masaryk University.Material and methods: All probands referred to our MH diagnostic centre from 2002 to 2022 were enrolled. Each proband was a representative of one unrelated family. Probands were investigated according to diagnostic guidelines valid at the time of reporting by molecular genetic testing and muscle in vitro contraction test (IVCT). All probands with completed MH diagnostics were included in the final analysis.Results: By the end of 2022, there were a total of 303 reports related to the risk of MH. A total of 236 IVCT tests were performed, 129 negatives and 107 positives. There were 223 persons susceptible to MH (MHS) registered from 75 Czech and 8 Slovak families. A diagnostic pathogenic variant in the RYR1 gene was found only in 37 MHS families (45%). MH was excluded in 87 families (MHN). Conclusion: In 20 years of systematic work, a unique set of 83 MHS families has been collected in our Czech and Slovak populations. Despite the routine availability of state-of-the-art MH diagnostics, more than half of our MH families do not have a confirmed MH genetic background and can benefit from scientific progress and further research.