This document addresses essential principles of genetic testing including modes of inheritance, different testing methodologies, and interpretation of variants. Additionally, the document presents the state of genetic testing for inherited arrhythmia syndromes, cardiomyopathies, sudden cardiac death (SCD), congenital heart disease (CHD), coronary artery disease, and heart failure. A discussion of aortopathies and hyperlipidaemia is beyond the scope of this document.