Klinefelter syndrome

Klinefelter syndrome is caused by the presence of an additional X chromosome. Normally, men have a chromosome set of XY, but affected individuals have an additional X chromosome (XXY). This genetic change occurs randomly during cell division and is not inherited. There are no known risk factors that increase the risk.

• Low testosterone production, leading to delayed or incomplete entry into puberty
• Small testes
• Infertility or reduced sperm production
• Enlarged breast tissue (gynecomastia)
• Less pronounced muscle mass and body hair
• Longer limbs, especially arms and legs
• Learning difficulties, particularly in the area of language development

The diagnosis is often made through a chromosome test (karyotype analysis) that detects the additional X chromosome. Blood tests to measure testosterone levels can also provide clues to the diagnosis, especially in adolescents or adults who show symptoms such as infertility or delayed puberty. A prenatal diagnosis is possible through an amniocentesis if a genetic test is conducted during pregnancy.

• Hormone replacement therapy (testosterone): Testosterone replacement therapy is often prescribed to support physical development during puberty, promote muscle growth, and enhance secondary sexual characteristics such as body hair.
• Cognitive and language support: Many affected boys benefit from speech and learning therapies to overcome developmental delays.
• Fertility treatment: In some men with Klinefelter syndrome, fertility is limited, but fertility treatments such as assisted reproduction can be helpful in some cases.
• Psychological support: Since Klinefelter syndrome is often associated with emotional and psychological challenges, psychological and social support measures can help those affected better cope with the disorder.

Since Klinefelter syndrome is a genetic anomaly, there are no specific preventive measures. However, early diagnosis and treatment can help improve the quality of life of those affected by providing hormonal, physical, and cognitive therapies.