RYR2 and Malignant hyperthermia: ARVD2 associated RYR2 mutations (p.R176Q, p.L433P, p.N2386I and p.T2504M) locate to two distinct clusters in the cytosolic part of the molecule that correspond to the mutational domains of the skeletal muscle RYR1 channel causing malignant hyperthermia (MH) or central core disease (CCD).