General Information About Klinefelter Syndrome
Disease Details and Frequently Asked Questions
While males should normally have a 46,XY chromosome arrangement, it is the condition of having a 47,XXY genetic makeup due to the addition of an extra female chromosome as a result of an error during cell division.
They become apparent after puberty. Tall stature (long arms and legs), significantly smaller and firmer testes than normal, sparse beard/body hair, muscle weakness, and breast enlargement (gynecomastia) are observed.
The extra X chromosome prevents the testicular tissue from fully developing. Undeveloped testes cannot produce enough of the testosterone hormone, which provides male-specific characteristics (voice deepening, muscle development).
Yes, the most prominent outcome of the syndrome is infertility. The vast majority of patients have no sperm cells in their semen at all (Azoospermia). However, today, with micro-TESE surgery, live sperm can be found inside the testes, creating a chance for IVF.
When presenting with complaints of delayed puberty or inability to have children, blood hormone tests show low testosterone and high FSH and LH hormones. The definitive diagnosis is made by identifying the extra X chromosome in the DNA via Chromosome Analysis (Karyotyping).
It is not possible to change the genetic condition. However, lifelong regular Testosterone Replacement Therapy (injection or gel) is applied to replace the patient's missing male hormone. This treatment prevents osteoporosis and improves muscle and sexual functions.
Our health library contents are prepared for informational purposes only and with scientific data available at the time of recording. For all your questions, concerns, diagnosis, or treatment regarding your health, please consult your doctor or a healthcare institution.
