Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Fumarase deficiency ?
    ### Response:
    What causes fumarase deficiency? Mutations in the FH gene cause fumarase deficiency. The FH gene provides instructions for making an enzyme called fumarase, which participates in a series of reactions allowing cells to use oxygen and generate energy. Mutations in the FH gene disrupt the enzyme's ability to do its job.
    