Complications of Klinefelter syndrome can include:

  • Delayed puberty
  • Noticeable physical features, such as sparse facial and body hair, unusually long legs and arms, lack of muscular development, and enlarged breast tissue
  • Learning disabilities, attention problems or social development issues
  • Infertility
  • Weak bones (osteoporosis)
  • Increased risk of varicose veins and other problems with blood vessels
  • Increased risk of breast cancer and cancers of the blood, bone marrow or lymph nodes
  • Increased risk of lung disease
  • Increased risk of autoimmune disorders, such as type 1 diabetes and lupus
  • Increased belly fat, which can lead to other health problems
  • Problems with sexual function

A number of complications caused by Klinefelter syndrome are related to low testosterone (hypogonadism). Testosterone replacement therapy reduces the risk of certain health problems, especially when therapy is started at the beginning of puberty.

June 25, 2013