Muscle disorders linked to RYR1 mutations in humans range in clinical presentation from malignant hyperthermia (Chelu et al., 2006; Durham et al., 2008; Yang et al., 2006) to core myopathies (Jungbluth et al., 2011) to congenital fiber type disproportion (Clarke et al., 2010). This evidence concerns the gene RYR1 and myopathy.