Overview Of Klinefelter Syndrome
Klinefelter syndrome is a genetic condition that occurs in males when they have an extra X chromosome.
Commonly Associated With
47 X-X-Y syndrome; XXY syndrome; XXY trisomy; 47,XXY/46,XY; Mosaic syndrome; Poly-X Klinefelter syndrome
Causes Of Klinefelter Syndrome
Most people have 46 chromosomes. Chromosomes contain all of your genes and DNA, the building blocks of the body. The 2 sex chromosomes (X and Y) determine if you become a boy or a girl. Girls normally have 2 X chromosomes. Boys normally have 1 X and 1 Y chromosomes.
This syndrome results when a boy is born with at least 1 extra X chromosome. This is written as XXY.
Klinefelter syndrome occurs in about 1 out of 500 to 1,000 baby boys. Women who get pregnant after age 35 are slightly more likely to have a boy with this syndrome than younger women.
Symptoms Of Klinefelter Syndrome
Infertility is the most common symptom of this syndrome.
Symptoms may include any of the following:
- Abnormal body proportions (long legs, short trunk, shoulder equal to hip size)
- Abnormally large breasts (gynecomastia)
- Infertility
- Sexual problems
- Less than normal amount of pubic, armpit, and facial hair
- Small, firm testicles
- Tall height
- Small penis size
Exams & Tests
Klinefelter syndrome may first be diagnosed when a man comes to the health care provider because of infertility. The following tests may be performed:
- Karyotyping (checks the chromosomes)
- Semen count
Blood tests will be done to check hormone levels including:
- Estradiol, a type of estrogen
- Follicle-stimulating hormone
- Luteinizing hormone
- Testosterone
Treatment Of Klinefelter Syndrome
Testosterone therapy may be prescribed. This can help:
- Grow body hair
- Improve the appearance of muscles
- Improve concentration
- Improve mood and self-esteem
- Increase energy and sex drive
- Increase strength
Most men with this syndrome are not able to get a woman pregnant. But, an infertility specialist may be able to help. Seeing a doctor called an endocrinologist may also be helpful.
