Genetic landscape of hereditary cardiomyopathies and arrhythmias in China.

Hereditary cardiomyopathies and arrhythmias are major contributors to cardiovascular morbidity and mortality. The advent of next-generation sequencing (NGS) has made genetic testing more accessible, which is crucial for precise diagnosis and targeted therapeutic strategies. The aim of this study is to explore the landscape of genetic variants, the relationship between specific variants and clinical phenotypes, and the impact on clinical decision-making in China. A total of 1536 probands (median age, 37 years; 1025 males [66.7%]) with suspected hereditary cardiomyopathy or arrhythmia (covering 15 clinical phenotypes) are recruited from 146 hospitals across 30 provinces and cities in China. Positive results are confirmed in 390 of 1536 probands, leading to a diagnostic yield of 25.4%. Forty-two and three-tenths percent (n = 169) of family members carry the same variants as positive probands. Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are the predominant phenotypes, with MYBPC3 variants having the highest frequency in HCM and TTN variants in DCM. In 76.9% of the positive probands, the identified variants are helpful in clinical management, family screening, and fertility. This large-scale study provides significant insights into the genetic landscape of hereditary cardiomyopathies and arrhythmias in China.