Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) cytochrome c oxidase deficiency ?
    ### Response:
    Cytochrome c oxidase deficiency is a genetic condition that can affect several parts of the body, including the muscles used for movement (skeletal muscles), the heart, the brain, or the liver. Signs and symptoms of cytochrome c oxidase deficiency usually begin before age 2 but can appear later in mildly affected individuals.
    