RYR2 and Prolonged QT interval: Some of these RyR2 mutations have been identified in patient groups screened for Long QT syndrome (Tester et al., 2005b), arrythmogenic right ventricular cardiomyopathy type 2 (ARVD2), in which there is histological evidence of fibrofatty streaks in the right ventricle and the tachycardia exhibits polymorphic characteristics (Tiso et al., 2001; Moric-Janiszewska & Markiewicz-Loskot, 2007) and unexplained drowning on post mortem (Tester et al., 2005a).