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 is suspected, a GP should arrange blood tests to check the levels of gonadotrophins (lutenising Hormone (LH) and follicle Stimulating Hormone (FSH)) and Testosterone in the blood. In patients with Klinefelter’s syndrome, tests characteristically show a low testosterone level, high sex hormone binding globulin (SHBG) and raised gonadotrophins. Testosterone levels are at their highest early in the morning (around 8.00 am to 9.00 am) therefore blood tests for testosterone should be taken around this time for accuracy. Levels taken at different times of the day will be lower and therefore less reliable. According to the Royal Free Hospital, the range of normal testosterone levels are between 9.9-28.5 nmol/l although readings will vary between laboratories. High LH, FSH 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. A genetic blood test, which looks at the pattern of the chromosomes i.e. the karyotype, is needed to confirm the diagnosis.
The type of hypogonadism which occurs in KS is called primary hypogonadism i.e. it is caused by a problem with the testicles themselves whereas secondary hypogonadism is caused by a malfunction in the parts of the brain which signal the testes to produce testosterone. 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.