Klinefelter Syndrome (KS)

What is Klinefelter Syndrome?

Klinefelter syndrome (KS) is also known as 47, XXY or XXY and describes the set of symptoms that are the consequence of two or more X chromosomes in males. The primary feature of Klinefelter syndrome is sterility. The condition is not inherited from one’s parents, occurs randomly, and the risk of developing Klinefelter syndrome is increased if the mother is older.

Those with the condition are usually of normal intelligence but do tend to develop reading difficulties and problems with speech. The genetic test known as karyotype is used to diagnose Klinefelter syndrome. In adult males lab tests such as hormone tests or a semen analysis is ordered in addition to the karyotype test. Klinefelter syndrome can be diagnosed before birth via genetic testing on the cells from the mother’s amniocentesis.

What are the Symptoms of Klinefelter Syndrome?

Some symptoms may be so subtle that the individual is unaware that they have the condition.

Prominent symptoms of Klinefelter syndrome include poor coordination, greater height, weaker muscles, less body hair, smaller genitals, breast growth, and less interest in sex which are noticed only during the onset of puberty.

How is Klinefelter Syndrome Treated?

Males with Klinefelter syndrome should be given testosterone around the time of puberty for proper sexual development. It’s important to note that testosterone doesn’t help infertility in males. Testosterone can be delivered to the individual via gel, skin patch, or injection. Educational support and speech therapy is recommend for boys who have language or learning problems.

Last Reviewed:
September 21, 2016
Last Updated:
September 01, 2017