Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to glycogen storage disease type I ?
    ### Response:
    Mutations in two genes, G6PC and SLC37A4, cause GSDI. G6PC gene mutations cause GSDIa, and SLC37A4 gene mutations cause GSDIb.  The proteins produced from the G6PC and SLC37A4 genes work together to break down a type of sugar molecule called glucose 6-phosphate.
    