RYR1 and myopathy: Dantrolene, a ryanodine receptor antagonist and the first line treatment for MH51 has been used successfully in some MH susceptible patients with severe cramps and myalgia and might be useful in this respect.3,52 Lastly, the emergence of permanent myopathies at an older age suggests a potential synergism between RyR1 dysfunction and the physiological aging process, emphasizing the importance of further longitudinal studies in this cohort extending into older age groups.