Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to spinocerebellar ataxia type 3 ?
    ### Response:
    Mutations in the ATXN3 gene cause SCA3. The ATXN3 gene provides instructions for making an enzyme called ataxin-3, which is found in cells throughout the body. Ataxin-3 is involved in a mechanism called the ubiquitin-proteasome system that destroys and gets rid of excess or damaged proteins.
    