PRDM16 and left ventricular noncompaction: The PR/SET domain 16 (PRDM16) protein directly affects transcriptional regulation.3 Mutation of the PRDM16 gene causes dilated (DCM) and left ventricular non-compaction cardiomyopathy (LVNC) in patients.4–7 Recently, rare variant association analysis linked LVNC to PRDM16 protein-truncating variants.8 These findings suggest that PRDM16 is a genetic factor that is critical for cardiac function, causing either monogenic cardiomyopathy or other myocardial phenotypes.