This is a multicentre, prospective cohort study designed to elucidate the natural history of dilated cardiomyopathy (DCM) associated with specific gene mutations in Chinese patients. By establishing a cohort of patients with inherited cardiomyopathy, the study will collect comprehensive data, including demographic characteristics, disease history, clinical features, prior treatments, current treatment patterns, clinical outcomes, and patient-reported outcomes (PROs). The objective is to describe the disease profile, current diagnostic and therapeutic landscape, clinical progression, and prognosis of this specific patient population in China. The data generated will provide a foundational basis for deepening the understanding of disease progression, identifying unmet clinical needs, and exploring potential surrogate endpoints for future clinical trials in drug development. The study plans to enroll 10 eligible patients with BCL-2-associated athanogene 3 (BAG3)-associated inherited DCM from 3 research sites across China.