Causes
In general, males have one Y and one X chromosome, while the number of X chromosomes in females is two. Klinefelter syndrome happens when a male infant is born with an additional X chromosome. This problem can be triggered by a defect during the development of sperm or egg. As a result, the baby might have this extra chromosome in all cells throughout the body. That is why Klinefelter is also known as XXY syndrome. Even though it is a genetic condition, Klinefelter syndrome is not inherited. Currently, it is estimated that around 1 in 1,000 newborn male babies might have this disorder. Further research is still needed to find out the underlying cause of these genetic changes. [2]
