Patients with pathogenic genetic variants in genes encoding proteins involved in the copper delivery into the CuA center, such as SCO1 (Leary et al., 2013), SCO2 (Hallas et al., 2018; Jaksch et al., 2000; Papadopoulou et al., 1999), and COA6 (Baertling et al., 2015; Ghosh et al., 2014), have been documented to present with infantile mitochondrial encephalomyopathy and cardiomyopathy, which is a similar clinical phenotype as the COX16 patients described here. Here, COX16 is linked to cardiomyopathy.