Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to cerebrotendinous xanthomatosis ?
    ### Response:
    Mutations in the CYP27A1 gene cause cerebrotendinous xanthomatosis. The CYP27A1 gene provides instructions for producing an enzyme called sterol 27-hydroxylase. This enzyme works in the pathway that breaks down cholesterol to form acids used in the digestion of fats (bile acids).
    