Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) dentatorubral-pallidoluysian atrophy ?
    ### Response:
    Dentatorubral-pallidoluysian atrophy, commonly known as DRPLA, is a progressive brain disorder that causes involuntary movements, mental and emotional problems, and a decline in thinking ability. The average age of onset of DRPLA is 30 years, but this condition can appear anytime from infancy to mid-adulthood.
    