Klinefelter syndrome only occurs in males and results from the presence of an extra chromosome X.
The prevalence is estimated at 1 in 500-1000 male births. Life expectancy is normal.
Most frequent clinical findings in patients with Klinefelter syndrome – 47,XXY
- Increased breast tissue
- Above average height
- Reduction in muscular mass
- Feminine body fat distribution
- Small testicles
Aaksis.org – American Association for Klinefelter Syndrome Information and Support (AAKSIS)
Orpha.net – The portal for rare diseases and orphan drugs