Klinefelter syndrome – 47,XXY

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

  • Infertility
  • Increased breast tissue
  • Above average height
  • Reduction in muscular mass
  • Feminine body fat distribution
  • Small testicles

Additional information

Aaksis.org – American Association for Klinefelter Syndrome Information and Support (AAKSIS)

Orpha.net – The portal for rare diseases and orphan drugs