Klinefelter syndrome is a rare genetic disorder caused by the presence of an extra X chromosome in boys. This chromosomal anomaly (XXY instead of XY) causes changes in physical and cognitive development, generating characteristics such as breast enlargement, lack of body hair or delayed development of the penis.
The diagnosis of Klinefelter syndrome is usually made in adolescence or early adulthood, when not all male characteristics are noted. To confirm the diagnosis, the doctor may recommend genetic and blood tests.
Although there is no cure for Klinefelter syndrome, it is possible to begin testosterone replacement therapy during adolescence, which allows many boys to develop more like their friends.
Main features
The main characteristics of Klinefelter syndrome are:
- Very small testicles;
- Absence of sperm;
- Slightly voluminous breasts;
- Large hips;
- Few facial hair;
- Reduced size penis;
- Voice higher than normal;
- Infertility.
These characteristics are easier to identify during adolescence, as this is when boys’ sexual development is expected to occur. However, there are other characteristics that can already be identified from childhood, especially related to cognitive development, such as having difficulty speaking, delay in crawling, problems concentrating or difficulty expressing feelings.
What causes the syndrome
Klinefelter syndrome occurs due to a genetic change that causes an extra X chromosome to exist in the boy’s karyotype, being XXY instead of XY.
Although it is a genetic change, this syndrome does not pass from parents to children and, therefore, there is no greater chance of having this change, even if there are other cases in the family.
However, in the case of a history of Klinefelter syndrome or other genetic alterations in the family, it may be interesting to undergo genetic counseling to check the possibility of genetic alterations. Understand how genetic counseling is carried out.
How to confirm the diagnosis
The diagnosis of Klinefelter syndrome is usually made in adolescence or early adulthood, when well-developed male characteristics are not identified. If the syndrome is suspected, the doctor may recommend carrying out a genetic test, known as cytogenetics, to evaluate the chromosomes, identifying, in the case of the syndrome, the presence of an extra X chromosome in the sexual chromosome pair (XY).
In addition, blood tests can be performed to assess hormone levels, such as FSH and testosterone, as well as tests to assess sperm quality, which also helps to confirm the diagnosis.
How the treatment is carried out
There is no cure for Klinefelter syndrome, but your doctor may advise testosterone replacement through injections into the skin or the application of patches, which gradually release the hormone over time.
In most cases, this treatment has better results when it is started in adolescence, as this is the period in which boys are developing their sexual characteristics, but it can also be done in adults, mainly to reduce some characteristics such as breast size or high tone of voice.
In cases where there is cognitive delay, it is recommended to undergo therapy with the most appropriate professionals. For example, if you have difficulty speaking, it is advisable to consult a speech therapist, but this type of support can be discussed with your pediatrician.
Bibliography
- CURATE, Roberta MOF; SESTARY, Sheila J.; GAMBA, Bruno F. et al. Klinefelter syndrome, an underdiagnosed condition: literature review. RRS-FESGO. Vol 3. 1 ed; 68-75, 2020
- TINCANI, Bruna J.; MASCAGNI, Bruno R.; PINTO, Robert D. et al. Klinefelter syndrome: an unusual diagnosis in pediatric patients. Journal of Pediatrics. Vol 88. 4 ed; 323-327, 2012
