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Klinefelter syndrome

  1. Home
  2. Cancer information
  3. Resources
  4. Glossary
  5. Klinefelter syndrome
Print

Description

Klinefelter syndrome is a genetic condition where males have an extra X chromosome. Instead of having one X chromosome and one Y chromosome (XY), they have two X chromosomes and one Y chromosome (XXY). Signs of Klinefelter syndrome include a lack of body and facial hair, enlarged breasttissue and cryptorchidism.

Klinefelter syndrome increases the risk of testicular and breast cancers.

Also called 47,XXY syndrome.

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