Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Pompe Disease ?
    ### Response:
    Pompe disease is a rare (estimated at 1 in every 40,000 births), inherited and often fatal disorder that disables the heart and skeletal muscles. It is caused by mutations in a gene that makes an enzyme called acid alpha-glucosidase (GAA). Normally, the body uses GAA to break down glycogen, a stored form of sugar used for energy.
    