Over the past several decades, the discovery of >20 missense, splicing, and frameshift mutations spanning the entire length of the obscurin gene (OBSCN) in patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), left ventricular non-compaction (LVNC), and arrhythmogenic right ventricular cardiomyopathy (ARVC) has increasingly implicated obscurin in the development of cardiac disease in humans (3–5). Here, OBSCN is linked to familial dilated cardiomyopathy.