Explore the current state of genetic testing for major sudden cardiac death (SCD)-predisposing genetic heart diseases in young patients through this comprehensive grand rounds presentation. Gain a deep understanding of genetic testing yield for major cardiomyopathies and channelopathies, and learn about the impact of positive genetic test results across diagnostic, prognostic, and therapeutic aspects of medicine. Recognize various phenotypes of SCD-predisposing conditions, including hypertrophic cardiomyopathy (HCM) and long QT syndrome (LQTS). Evaluate available genetic tests for HCM and LQTS, assessing their yield and impact on medical practice. Learn to interpret genetic tests as probabilistic tools and incorporate them into personalized medicine approaches. Note that this educational program may contain graphic medical content.