XXY is a male chromosome. People with XXY chromosomes have Klinefelter syndrome, a genetic condition that affects development in people who are assigned male at birth. The presence of a Y chromosome is what determines a person's sex as male. While the X chromosome is present in everyone, the Y chromosome is the key indicator of a male sex.
Examples of XXY Individuals:
- Individuals with Klinefelter syndrome have an extra copy of the X chromosome.
- They are assigned male at birth but may have some female characteristics due to the presence of two X chromosomes.
- The presence of the Y chromosome, however, confirms their biological sex as male.
