XYY syndrome – 47,XYY

XYY syndrome, similar to Klinelfelter syndrome, only affects males, and is caused by an extra copy of chromosome Y.

The prevalence is estimated at 1 in 1,000 male births. XYY syndrome is not inherited and is not affected by advanced parental age. Life expectancy is normal.

Most frequent clinical findings in patients with 47, XYY syndrome:

The syndrome does not cause any unusual physical characteristics or medical problems and is only detected after a genetic analysis.

  • A small percentage is diagnosed with autistic disorders which affect their communication and social interaction abilities.
  • Normal appearance, usually with a tall stature
  • Increased vulnerability (behavior and stress tolerance problems)

Additional information

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