"XXY: There are 23 pairs of chromosomes found in each cell of the body, and each contain genes that determine our colouring, our features, and our sex. Women inherit two X chromosomes -- one from each parent, written 46,XX. Men inherit an X chromosome from their mothers and a Y chromosome from their fathers, written 46,XY. Some individuals, however, have an additional X chromosome in their chromosomal arrangement, referred to as 47,XXY, or more commonly, just XXY. The cause is unknown, yet XXY occurs in approximately 1 in every 500 to 1000 live male births, making it one of the most common chromosome variations."
