Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Trisomy 17 mosaicism ?
    ### Response:
    What causes trisomy 17 mosaicism? Trisomy 17 mosaicism can arise due to errors in cell division that occur after conception. For example, at the time of conception, the fetus may actually have trisomy 17 in all of its cells; however, during cell division, some of the cells lose the extra chromosome 17.
    