Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to autosomal recessive spastic ataxia of Charlevoix-Saguenay ?
    ### Response:
    Mutations in the SACS gene cause ARSACS. The SACS gene provides instructions for producing a protein called sacsin. Sacsin is found in the brain, skin cells, muscles used for movement (skeletal muscles), and at low levels in the pancreas, but the specific function of the protein is unknown.
    