Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Gerstmann-Straussler-Scheinker disease ?
    ### Response:
    What causes Gerstmann-Straussler-Scheinker disease? Gerstmann-Straussler-Scheinker disease (GSS) is usually caused by certain changes (mutations) in the PRNP gene. PRNP encodes a protein called prion protein. Although the exact function of this protein is unknown, it appears to play an important role in the human brain and other tissues throughout the body.
    