Hereditary Dilated Cardiomyopathy: Recent Advances in Genetic Diagnostics

Dilated cardiomyopathy (DCM) is the most common cause of heart failure in young adults and up to 50% of idiopathic DCM is thought to be caused by genetic mutations in candidate genes. Although a genetic diagnosis can confirm a clinical diagnosis of hereditary DCM, genetic testing has not been easily accessible due to genetic heterogeneity and complexity. Next-generation sequencing (NGS) technologies have recently been introduced, and genetic testing for multiple genes is currently available and more than 40 different genes have been associated with DCM. In Korea, the government has supported genetic diagnosis for patients with idiopathic DCM. When a targeted gene panel with NGS technology was used, the detection rate was about 40%. MYBPC3, LMNA, and MYH7 were the most frequently identified genes, and the pattern of causative genes was different from previous reports. In the analysis, a significant number of subjects (42.0%) had rare or novel unspecified variants in DCM candidate genes, which should be assessed as potential causative mutations. Developing a more comprehensive test panel with additional DCM genes and whole exome sequencing will improve the detection rate, and allow genetic testing to be an option for patients with idiopathic DCM. However, all genetic variations are not pathogenic mutations, and the majority of reported mutations in DCM are unique to a single family, which makes genetic data interpretation more difficult. Therefore, clinical features and familial history integration are needed to improve clinical decision making.