Klinefelter Syndrome

Klinefelter Syndrome, named for Dr. Henry Klinefelter, is also known as the XXY Syndrome. Men born with Klinefelter syndrome carry an extra X in addition to their XY chromosome, so that their genetic chromosomal pattern becomes XXY.

Klinefelter Syndrome is thought to be one of the most common chromosomal abnormalities in humans, and is also the most common abnormality associated with infertility and hypogonadism.

Men diagnosed with Klinefelter syndrome can have normal sex lives, but 95-99% will be infertile because their bodies produce little to no sperm. XXY Syndrome also affects testosterone levels and leaves men with weaker muscles, less hair, and enlarged breast tissue.

Symptoms of Klinefelter Syndrome may begin to appear during infancy. XXY chromosome babies may sit, crawl, and walk later than other infants. Due to the lack of testosterone at the onset of puberty, boys with this syndrome will have less muscular bodies, taller and longer limbs, little facial and body hair, broader hips, larger breasts, and lower energy compared to other boys their age. After reaching adulthood, men with XXY Syndrome will be more likely to suffer from autoimmune disorders, breast cancer, osteoporosis, tooth decay, and vein diseases.

In addition to physical symptoms, XXY Syndrome sufferers develop language slower than other children, exhibit problems using language to express emotions, and experience reading, writing, and processing problems.

Men diagnosed with Klinefelter Syndrome will require assistance with their education and will need therapy for their speech as well as for their physical, behavioural, and mental health. XXY men may also need hormone replacement therapy, as testosterone therapy will help to build stronger muscles and bones, deepen the voice, and promote the growth of facial and body hair. Testosterone will also help to boost the libido, provide increased energy, heighten the ability to concentrate, and decrease the need for sleep.

A daily injection is required to maintain testosterone therapy, and benefits will cease when treatment stops. Men receiving testosterone therapy should schedule regular prostate exams.

The only way to properly diagnose Klinefelter syndrome is to have a karyotype performed, which will identify the chromosomal count in your body.

Speak to your doctor if you have any concerns about Klinefelter Syndrome.