Discussion:
Klinefelter, Syndrome
How is Klinefelter Syndrome Inherited?
Klinefelter syndrome is a term used to describe men who are born with an extra X chromosome in the majority of their cells. The cells of a normal, healthy person contain two copies of each of 23 chromosomes, for a total of 46 chromosomes per cell. Everyone has two sex chromosomes. Males have one X and one Y chromosome, while females have two X chromosomes. The X and Y chromosomes are called sex chromosomes because they contain the genetic information that determines male and female sexual characteristics. Klinefelter syndrome occurs when a male is born with an extra X chromosome in all or most of his cells. Sometimes people with this disorder are called XXY males. Even though a person with Klinefelter syndrome has an extra X chromosome, he is considered a male because he has a Y chromosome.