Further cases may elucidate whether these patients have primary cardiac disease [as is the case for patients with variants in the related MRPS14, MRPS22, MRPL3, and MRPL44 genes (Carroll et al. 2013; Distelmaier et al. 2015b; Friederich et al. 2021; Galmiche et al. 2011b; Jackson et al. 2019b; Smits et al. 2011b)] or whether this cardiomyopathy is secondary to chronic kidney disease, for example, if patients present with cardiac disease in the absence of, or prior to the development of, kidney disease. This evidence concerns the gene MRPS22 and heart disorder.