Genetic cardiomyopathy is increasingly recognised and can lead to heart failure, arrhythmia and sudden cardiac death. Some gene positive patients have rapidly progressive disease with high rates of heart failure and cardiac transplantation, while others present with SCD. Other gene positive patients will never develop cardiomyopathy. At present, we cannot distinguish between these groups and rely on expensive and labour-intensive surveillance by electrocardiography, echocardiography and sometimes cardiac magnetic resonance imaging. This study will investigate existing and novel biomarkers (including blood, urine electrocardiographic and imaging) at various stages of disease in patients with a personal or family history of TTN, MYBPC3, LMNA, FLNC or DSP gene variant, which are known to cause cardiomyopathy.