Cardiogenetics: a Primer for the Clinical Cardiologist.

### Learning objectives Over the past decade, there has been increased recognition of genetic causes for many types of cardiovascular disease, with significant implications for patient management depending on the specific genetic condition. Although polygenetic associations with atherosclerotic cardiovascular disease have long been known, a number of inherited single-gene variants resulting in unique cardiovascular phenotypes has been recognised only more recently. Previously, it was difficult to make a genetic diagnosis because testing was expensive and rarely available. The current era of massively parallel DNA sequencing and large volume commercial labs has resulted in wider availability of gene panels and even exome and genome sequencing for use in cardiovascular genetics. Dozens to hundreds of genes of interest can be sequenced at lower cost, far more rapidly than a decade ago, making clinical testing more accessible than ever before. Many cardiology practice guidelines now incorporate genetic data in recommendations for diagnosis and personalised clinical management. Thus, clinical cardiologists need to understand the basic principles of cardiovascular genetics, recognise which patients might have an underlying genetic condition and refer patients for genetic testing when appropriate. Patients and families with inherited cardiovascular conditions also will expect their physicians to engage in informed shared decision making about clinical management. In this review article, we summarise basic principles of medical genetics and provide a practical approach to clinical genetic testing focusing on three categories of cardiovascular diseases: aortopathies, cardiomyopathies and arrhythmias. Genetic variations in patients are broadly divided into two categories: benign common nucleotide variations versus …