SCO2 (synthesis of cytochrome C oxidase 2) functions as a copper metallochaperone essential for mitochondrial respiratory chain complex IV assembly and cellular copper homeostasis 1. The protein facilitates copper incorporation into cytochrome c oxidase subunit II (MT-CO2/COX2), working in conjunction with SCO1 to deliver copper to the Cu(A) site of this critical respiratory enzyme 1. SCO2 may also function as a thiol-disulfide oxidoreductase, regulating the redox state of cysteines in SCO1 during MT-CO2/COX2 maturation 1. Located in the mitochondrial inner membrane, SCO2 plays a crucial role in cellular energy metabolism through its involvement in electron transport chain function. Mutations in SCO2 cause mitochondrial complex IV deficiency, leading to fatal infantile cardioencephalomyopathy with cytochrome c oxidase deficiency 2. This severe genetic disorder demonstrates the critical importance of proper copper metabolism in mitochondrial function. SCO2 deficiency has also been associated with hereditary motor neuropathies, expanding the clinical spectrum of SCO2-related disorders 3. Therapeutic approaches using protein replacement therapy have shown promise, with recombinant SCO2 protein successfully restoring partial COX activity in patient-derived fibroblasts 2. Additionally, novel mRNA-based delivery platforms targeting SCO2 deficiency represent emerging treatment strategies for this devastating mitochondrial disorder 2.