SCN5A, encoding the alpha subunit of the cardiac sodium channel Nav1.5, is crucial for the generation and propagation of the action potential in cardiomyocytes. Influx of sodium ions through voltage-gated sodium channels it codes for is essential for proper electrical conduction within the heart [1,4].

SCN5A mutations are associated with a variety of cardiac disorders. In Brugada syndrome (BrS), SCN5A variants are found in about 20%-25% of patients. Compared to SCN5A-negative BrS patients, SCN5A-positive ones more frequently have spontaneous type 1 electrocardiogram, history of syncope, and documented arrhythmias, along with longer PQ and QRS intervals. The presence of SCN5A rare variants is significantly associated with the risk of major arrhythmic events in BrS patients [2]. SCN5A-related etiology also shows greater electrophysiological abnormalities in BrS patients, such as conduction disorder [3]. Moreover, SCN5A mutations may be linked to cardiomyopathy, though the pathways remain unclear [4].

In conclusion, SCN5A is vital for cardiac electrical conduction. Studies on SCN5A, especially through research on its variants in diseases like Brugada syndrome and potential links to cardiomyopathy, have enhanced our understanding of cardiac channelopathies. These insights may contribute to better risk assessment and treatment strategies for related cardiac disorders.