Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to chorea-acanthocytosis ?
    ### Response:
    Mutations in the VPS13A gene cause chorea-acanthocytosis. The VPS13A gene provides instructions for producing a protein called chorein; the function of this protein in the body is unknown. Some researchers believe that chorein plays a role in the movement of proteins within cells.
    