Symptoms of Klinefelter syndrome

Klinefelter syndrome doesn't usually cause any obvious symptoms early in childhood, and even the later symptoms may be difficult to spot.

Many boys and men don't realise they have it.

Possible features, which aren't always present, may include:

  • inbabies and toddlerslearningto sit up, crawl, walk and talk later than usual, being weaker, quieter and more passive than usual
  • in childhood shyness and low self-confidence, problems with reading, writing, spelling and paying attention, mild Dyslexia and/or dyspraxia , low energy levels, difficulty socialising or expressing feelings
  • inteenagersgrowing taller than expected for the family (with long arms and legs), broad hips, poor muscle tone and slower than usual muscle growth, reduced facial and body hair that starts growing later than usual, a small penis and testicles, enlarged breasts (gynaecomastia)
  • in adulthood inability to have children naturally (infertility) and a low sex drive , in addition to the physical characteristics mentioned above
Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018