Guidelines for Genetic Testing of Inherited Cardiac Disorders
Inherited gene variants have been implicated increasingly in cardiac disorders but the clinical impact of these discoveries has been variable. For some disorders, such as familial hypertrophic cardiomyopathy, long QT syndrome, and familial hypercholesterolaemia, genetic testing has a high yield and has become an integral part of family management. For other disorders, including dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and atrial fibrillation, relatively less is known about the genes involved and genetic testing has a lower yield. Recent advances in sequencing and array-based technologies promise to change the landscape of our understanding of the genetic basis of human disease and will dramatically increase the rate of detection of genomic variants. Since every individual is expected to harbour thousands of variants, many of which may be novel, interpretation of the functional significance of any single variant is critical, and should be undertaken by experienced personnel. Genotype results can have a wide range of medical and psychosocial implications for affected and unaffected individuals and hence, genetic testing should be performed in a specialised cardiac genetic clinic or clinical genetics service where appropriate family management and genetic counselling can be offered.