PROX1 (Prospero Homeobox 1) gene in the novel PROX1 locus, was previously reported as an important regulator of cardiac development and myocardial growth.33,34 A knock-out mouse model (Mouse Genome Informatics:97772) showed myofibrillar disarray, chamber dilatation and systolic dysfunction, which are all relevant cardiomyopathy-related traits. This evidence concerns the gene PROX1 and cardiomyopathy.