Human heterozygous MYPN gene mutations have been associated with HCM, DCM, and RCM (Bagnall et al., 2010; Duboscq-Bidot et al., 2008; Meyer et al., 2013; Purevjav et al., 2012) and their effect in vivo has been studied in two animal models: transgenic mice overexpressing the MYPN-Y20C variant (allele frequency of 9.34E-4; GnomAD v.2.2.1) linked to DCM and HCM in human (Purevjav et al., 2012), and knockin mice carrying the MYPN-Q526X nonsense mutation, equivalent to the human MYPN-Q529X mutation associated with RCM (Huby et al., 2014). Here, MYPN is linked to cardiomyopathy, familial restrictive, 1.