Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to familial paroxysmal nonkinesigenic dyskinesia ?
    ### Response:
    Mutations in the PNKD gene cause familial paroxysmal nonkinesigenic dyskinesia. The function of the protein produced from the PNKD gene is unknown; however, it is similar to a protein that helps break down a chemical called methylglyoxal. Methylglyoxal is found in alcoholic beverages, coffee, tea, and cola.
    