Klinefelter Syndrome
A genetic disorder in males caused by having one or more extra X chromosomes. Males with this disorder may have larger than normal breasts, a lack of facial and body hair, a rounded body type, and small testicles.
About Klinefelter Syndrome (KS)
The term “Klinefelter (pronounced KLAHYN-fel-ter) syndrome,” or KS, describes a set of features that can occur in a male who is born with an extra X chromosome (pronounced KROH-muh-sohm) in his cells. It is named after Dr. Henry Klinefelter, who identified the condition in the 1940s.
Usually, every cell in a male’s body, except sperm and red blood cells, contains 46 chromosomes. The 45th and 46th chromosomes—the X and Y chromosomes—are sometimes called “sex chromosomes” because they determine a person’s sex. Normally, males have one X and one Y chromosome, making them XY. Males with KS have an extra X chromosome, making them XXY.
KS is sometimes called “47,XXY” (47 refers to total chromosomes) or the “XXY condition.” Those with KS are sometimes called “XXY males.”…Read more about Klinefelter Syndrome NIH – National Institute of Child Health and Human Development