ically. The extra X chromosome can come from either the mother or the father. It is thought that older parents may be more likely to have a child with Klinefelter’s syndrome; this is probably because the risk of chromosomal abnormalities increases with age.
How is Klinefelter’s syndrome diagnosed?
Where Klinefelter’s syndrome is suspected, blood tests will be carried out to assess levels of testosterone and gonadotrophins (luteinising hormone and follicle stimulating hormone). In patients with Klinefelter’s syndrome, blood tests characteristically show a low testosterone level, high sex hormone binding globulin (SHBG) and raised gonadotrophins.
The diagnosis of Klinefelter’s syndrome is confirmed by chromosomal analysis (karyotyping), which involves a blood test. This is usually carried out as an outpatient.
Karyotyping can also be performed during pregnancy by analysing the fluid surrounding the foetus (amniocentesis) or by obtaining placental tissue (chorionic villus sampling). Both these procedures carry some risk and are performed as an inpatient.
How is Klinefelter’s syndrome treated?
The underlying chromosomal problem (XXY) cannot be changed, so the aim of treatment is to help with symptoms and prevent complications in the long-term. Early identification of affected individuals is therefore helpful. Treatment will differ among individuals depending on their age at diagnosis and level of symptoms experienced.
Testosterone replacement therapy is important where levels are low, and may be required from the start of puberty. The dose is adjusted to maintain appropriate testosterone concentrations. Testosterone can be given in a number of ways but is usually given by gel, which is rubbed onto the skin every day, or by injection. This is done as an outpatient.
Testosterone replacement therapy helps to improve testosterone levels in order to aid muscle development, facial and body hair growth, and sex drive. It also helps to improve self-esteem, mood and maintain bone health. In addition, some men with Klinefelter’s syndrome may benefit from specialised fertility treatment to increase their chance of having children.
In individuals with Klinefelter’s syndrome who have developed breast enlargement, this sometimes becomes permanent. In these cases, surgery may be offered to restore normal male appearances.
Physical and occupational therapy may be helpful in affected boys with coordination and muscle problems.
Speech and behavioural therapy can help with speech difficulties, developing language skills, confidence issues and academic problems. It is important that these interventions are implemented as early as possible during childhood.
Are there any side-effects to the treatment?
Testosterone replacement is generally well-tolerated. Care must be taken when given to anyone with prostate problems. While on testosterone replacement therapy, a blood test is performed at least annually to check testosterone levels, blood count and also the health of the prostate (in men over 50 years of age). If testosterone replacement therapy is given by topical gel, this can sometimes lead to irritation of the skin at the site of application. If given by intramuscular injection, this can rarely cause pain and swelling at the site of the injection.
Less common side-effects include headache, mood change, nausea, jaundice, increased red blood cells, high blood pressure and fluid retention.
What are the longer-term implications of Klinefelter’s syndrome?
Adults with Klinefelter’s syndrome are more likely to have a number of health issues such as osteoporosis; obesity; varicose veins and leg ulcers; development of autoimmune conditions (diabetes mellitus, systemic lupus erythematosus, thyroid problems); chest conditions (bronchitis and emphysema); and there may be an increase in some cancers (breast cancer, germ cell tumours, non-Hodgkin’s lymphoma). Men with Klinefelter’s syndrome are also thought to be at an increased risk of developing chronic health problems such as diabetes, cardiovascular, respiratory and gastrointestinal disease. All people