The heritability of cardiac conduction disease has been observed and reported for decades. These diseases frequently manifest as progressive and variable degeneration of the cardiac conduction tissues at young ages. Recently mutations in the SCN5A gene encoding the Nav1.5 channel have been identified as causes for these conduction abnormalities, improving the ability to diagnose and understand this disease process. Additionally, there has been increased detection of overlap syndromes characterized by varied phenotypic manifestations of certain mutations beyond conduction disease. Although the understanding of these heritable disorders continues to improve, treatment options remain limited to pacemaker support.