Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) 47 XXX syndrome ?
    ### Response:
    47 XXX syndrome, also called trisomy X or triple X syndrome, is characterized by the presence of an additional (third) X chromosome in each of a female's cells (which normally have two X chromosomes). An extra copy of the X chromosome is associated with tall stature, learning problems, and other features in some girls and women.
    