Seven mutations were identified in the Repeat12 domain (Figure 4D), among which five of them from RyR1 (G893S, N899K, A933T, R1043G, and G1049S) are associated with MH (Levano et al., 2009), while the other two from RyR2 (R1013Q and R1051P) are associated with CPVT (Medeiros-Domingo et al., 2009). This evidence concerns the gene RYR2 and catecholaminergic polymorphic ventricular tachycardia.