CAMK2G and hyperinsulinemic hypoglycemia, familial, 4: (Supplemental Figure S4B) These results suggest that autophagic deficiency (increased LC3II/I ratio, sarcomere disarrangement) and arrhythmogenic calcium activities (calcium handling abnormalities and irregular beating) are separately regulated in the DD cardiomyocytes, and our data indicated a potential therapeutic target to prevent arrythmia and sudden cardiac death in DD patient through targeting the overload of ROS and excess activation of CaMKII.