Provision of a genetic diagnosis can have a profound impact on the treatment of patients, and in five of our patients, it was considered life-saving; a family diagnosed with the newly described arrhythmia syndrome, cardiac ryanodine receptor (RyR2) calcium release deficiency syndrome [119], was prescribed flecainide for protective effect against ventricular arrhythmia and sudden cardiac death [120]. This evidence concerns the gene RYR2 and Ventricular arrhythmia.