Genetics of Sudden Cardiac Death

Cardiomyopathies (DCM, HCM, and ACM) and primary arrhythmogenic disorders (BrS, LQTS, and CPVT) represent the most common causes of sudden cardiac death (SCD) in young individuals. Systematic genome-wide single-nucleotide polymorphism (SNP) analyses and genome-wide association studies (GWASs) have enabled the identification of numerous genetic variants associated with cardiovascular diseases. Body: Genetic testing for cardiomyopathies and inherited channelopathies primarily involves panel testing of genes with definitive and strong evidence of disease association; genes supported by moderate evidence may also be considered. Cardiomyocytes express a variety of proteins implicated in the pathogenesis of genetic cardiomyopathies, including sarcomeric, cytoskeletal, desmosomal, and nuclear envelope proteins. Inherited cardiac channelopathies result from mutations in genes encoding cellular components that influence calcium ion availability or affect membrane ion channels, including sodium, potassium, and calcium channels. Common variants associated with SCD are found in genes encoding cardiac ion channels (e.g., SCN5A, KCNQ1, and KCNH2), calmodulin (CALM2), sarcomeric proteins (MYH7, MYBPC3, TTN, and TNNI3), and desmosomal proteins (RyR2 and DES).

This review demonstrates that specific genetic variants are significantly associated with an increased risk of SCD. The evidence underscores the importance of genetic screening and early intervention in individuals with a family history of SCD or other risk factors for inherited cardiac disorders predisposing to SCD. Future research should focus on gene-specific management strategies for familial cardiomyopathies and inherited channelopathies, with the goal of improving targeted genetic therapies and reducing the burden of sudden cardiac death.