Genetics Home > Klinefelter -- The Disease
Klinefelter syndrome is a genetic disorder affecting 1 in 500 to 1,000 males. People with this condition have an extra X chromosome in each cell. Klinefelter syndrome affects male sexual development, often causing symptoms such as:
- Breast development
- Sparse facial and body hair
- Small testes.
Affected males may also have low levels of the hormone testosterone when they reach puberty, due to the abnormal development of their testicles. Since it is a chromosomal disorder, Klinefelter syndrome has no cure. However, treatment options such as testosterone treatment or surgery are available to help control symptoms.
(For more information, including why symptoms of the disease can vary, click Klinefelter Syndrome.)