Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Leigh's Disease ?
    ### Response:
    Leigh's disease is a rare inherited neurometabolic disorder that affects the central nervous system. This progressive disorder begins in infants between the ages of three months and two years.Rarely, it occurs in teenagers and adults.Leigh's disease can be caused by mutations in mitochondrial DNA or by deficiencies of an enzyme called pyruvate dehydrogenase.
    