RYR1 and rhabdomyolysis: We hypothesize that the activity of these enzymes may be responsible in part, for the altered expression levels of muscle transcripts since they strongly influence the structure of chromatin, by rendering it more accessible (euchromatin) or less accessible (heterochromatin) to transcription.38,39 Our results show that the expression levels of DNMTs and HDACs were similar in muscles from healthy controls (Fig. 3A) and disease controls, i.e. patients with RYR1-related exertional rhabdomyolysis (Fig. 3B).