Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to deoxyguanosine kinase deficiency ?
    ### Response:
    The DGUOK gene provides instructions for making the enzyme deoxyguanosine kinase. This enzyme plays a critical role in mitochondria, which are structures within cells that convert the energy from food into a form that cells can use. Mitochondria each contain a small amount of DNA, known as mitochondrial DNA or mtDNA, which is essential for the normal function of these structures.
    