Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) glycogen storage disease type 0 ?
    ### Response:
    Glycogen storage disease type 0 (also known as GSD 0) is a condition caused by the body's inability to form a complex sugar called glycogen, which is a major source of stored energy in the body. GSD 0 has two types: in muscle GSD 0, glycogen formation in the muscles is impaired, and in liver GSD 0, glycogen formation in the liver is impaired.
    