MRPS22 and chronic kidney disease: 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.