Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to hereditary multiple osteochondromas ?
    ### Response:
    Mutations in the EXT1 and EXT2 genes cause hereditary multiple osteochondromas. The EXT1 gene and the EXT2 gene provide instructions for producing the proteins exostosin-1 and exostosin-2, respectively. The two exostosin proteins bind together and form a complex found in a cell structure called the Golgi apparatus, which modifies newly produced enzymes and other proteins.
    