Klinefelter syndrome (KS) or 47,XXY syndrome is a condition of intersex affecting approximately 1/500 AMAB individuals, making it one of the most common chromosomal conditions of intersex. It results from having two or more X chromosomes and one Y chromosome (XXY) rather then just XY. Symptoms may include greater height, poor coordination, less body hair, decreased ability to gain muscle, breast growth, lower sex drive, and reduced fertility. Symptoms are typically not noticed until puberty. Often, symptoms may be subtle and many people do not realize they are affected. Symptoms are typically more severe if three or more X chromosomes are present.