Genetics and genetic testing of dilated cardiomyopathy: a new perspective

The completion of the Human Genome Project was a landmark achievement, but as clinical genetic testing becomes more mainstream, the extent of remarkable genetic variation is increasingly being appreciated. Newer DNA sequencing technology can now complete the sequencing of an entire human genome several times over in a matter of days, but this will undoubtedly add new challenges to the difficulty of distinguishing true pathogenic variants from benign variants in diagnostic genetics and in the research setting. The recent discovery of the role of titin gene (TTN) mutations in dilated cardiomyopathy (DCM) will make genetic testing in this disease more efficient. Furthermore, better understanding of genotype-phenotype associations will assist clinicians in identifying early stages of disease and providing more appropriate treatments. This high level of complexity requires an expert genetic team to offer counseling and to manage, deliver, and follow-up over time the results of genetic testing, which is particularly important for screening of family members potentially at risk. In DCM, genetic testing may be useful for the identification of non-carriers and asymptomatic carriers, as well as for prevention strategies, sport recommendations, and defibrillator implantation. It can also guide reproductive decision-making including utilization of pre-implantation genetic diagnostic strategies.