Klinefelter Syndrome (KS) is a condition that only occurs in men as a result of an extra X chromosome. It is named after Dr. Henry Klinefelter who first discovered the syndrome in 1942 and was able to link the symptoms back to men with an extra X chromosome. The most common symptom of KS is infertility.
Humans have 46 chromosomes, which contain a person’s genes and DNA. Two of these chromosomes determine a person’s gender. Both of the sex chromosomes in females are called X chromosomes (XX) while males have an X and Y chromosome (XY). Klinefelter Syndrome is the result of an extra X chromosome (XYX). It is found in 1 out of every 500-1,000 newborn males. The additional sex chromosome results from a random error during the formation of the egg or sperm in a process called meiosis – cell division that forms the egg and sperm cells (reproductive cells).
KS is a genetic condition but it is not inherited from your parents. Because of the error in cell division, called non-disjunction, an extra copy of the X chromosome is formed. Women who get pregnant late in life (after the age of 35) are more prone to give birth to men with an extra X chromosome.
Symptoms of KS are first noticed when a man goes through puberty. Puberty may be late or incomplete if a man has KS. Sometimes the condition may only be diagnosed if a male and his partner are attempting to conceive a child.
The typical symptoms of KS are:
- Small testes
- Decreased facial hair
- Gynaecomastia (enlarged breasts)
- Decreased pubic hair
- A tall thin body with disproportionately long arms and legs
Male children with KS may also experience:
- A delay in learning how to walk
- Dyspraxia (coordination problems)
- Speech and language delays and difficulties
- Attention problems
- Behavior problems (boys with KS tend to be shy and have low self confidence; they also appear to be immature)
In addition to the symptoms listed above, men with KS may also have problems getting an erection and/or have a low libido. They may also experience anxiety and depression and appear less muscular than other men. Some men with KS have reported symptoms of osteoporosis which develops early in life as opposed to later
KS can be diagnosed by performing a karyotype test. This test takes a blood sample from a man and the chromosomes are studied to reveal if there is an extra chromosome present. If you have a child later in life, you can also test in advance to see if your child will have the extra chromosome with an antenatal screening. During this screening, a sample of the amniotic fluid is taken from the womb and from there a karyotype test is performed to see if the baby has KS.
If you are diagnosed with KS, there are a variety of treatment options available. The main treatment for KS is testosterone replacement. It will boost your low levels and should typically begin at puberty and will be needed for the rest of your life. The testosterone treatment will help strengthen muscle tissue, increase facial and body hair, increase the libido, enlarge the testes, improve your mood and self esteems and protect you from osteoporosis.
If you have KS and are considering having children, you will need to seek the help of an infertility specialist. The specialist will determine if there are any viable sperm in your testes and if they can be extracted and then used for IVF (in vitro fertilization).
Most men who have Klinefelter syndrome can expect to have a normal and productive life. Early diagnosis, in conjunction with educational interventions, medical management, and strong social support will optimize each individual’s potential in adulthood.