Diagnosis – Adults

Early diagnosis and a good understanding of the implications of Klinefelter’s Syndrome (KS) can improve life for both the person with the condition and also those with whom they have close contact. The Klinefelter’s Syndrome Association (KSA) is working to raise the profile of the condition generally, but within the medical profession in particular.

If KS/XXY is suspected, a GP should arrange a number of blood tests to check the levels of:

  • lutenising Hormone (LH)

  • follicle Stimulating Hormone (FSH)

  • sex hormone binding globulin (SHBG)

  • testosterone (T).

    In patients with KS/XXY, results will show high levels of the first three and low testosterone level. Tests for testosterone levels should be taken early in the morning (around 8.00 am to 9.00 am). Levels taken at different times of the day will be lower and less reliable.

    The range of normal testosterone levels are between 9.9 and 28.5 nmol/l, This is according to the Royal Free Hospital. Readings will vary between laboratories.

    High LH, FSH, SHGB and low testosterone levels indicate that the testes are producing little or no testosterone

    This is called hypogonadism and it can have causes other than KS/XXY. A genetic blood test, is needed to confirm the diagnosis.

    The type of hypogonadism which occurs in KS/XXY is called primary hypogonadism i.e. it is caused by a problem with the testicles themselves.

    Semen analysis generally shows the absence of sperm in the ejaculate and a bone density scan (DEXA Scan) may reveal osteoporosis – thinning of the bones.

    Next… ‘Trigger’ times for diagnosis