Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to 47,XYY syndrome ?
    ### Response:
    People normally have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY).
    