Report of joint hypermobility in malignant hyperthermia susceptible patients: Observational study with a case-control descriptive design.

Background: Hypermobility is the capacity to perform joint movements in amplitudes greater than normal. Hypermobility is present in nearly 100 % of congenital myopathy central core disease (CCD) patients but is sporadically described in the allelic disease malignant hyperthermia (MH). Our objective was to investigate the frequency/characteristics of hypermobility in MH susceptible patients as compared to a control group, aiming the identification of correlations between hypermobility and demographic/clinical findings in MH patients.