KLINEFELTER SYNDROME

• 0.2% of live male births.
• 80% are XXY
  10% are mosaic XY/XXY
  10% are XXYY and other less frequent types.

Testis - Normal prior to puberty and small in pospubertal male.
Kidneys - Symmetrically enlarged, small 1-8 mm cysts.
Gynecomastia after puberty.
Sparse facial and axillary hair.