Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to adult polyglucosan body disease ?
    ### Response:
    Mutations in the GBE1 gene cause adult polyglucosan body disease. The GBE1 gene provides instructions for making the glycogen branching enzyme. This enzyme is involved in the production of a complex sugar called glycogen, which is a major source of stored energy in the body.
    