Klinefelter syndrome is a chromosomal condition that describes boys and men with common features, physical traits and medical conditions that are caused by the presence of an extra X chromosome (i.e., XXY).
Both males and females generally have 46 chromosomes. In females, this includes two X chromosomes, while males have one X and one Y chromosome.
The most common form is the classic type, but there are variations.
It is estimated that one in 500 to 1,000 males are born with KIinefelter syndrome.
Klinefelter syndrome does not usually cause any obvious symptoms early in childhood, and many boys and men often do not realise they have KIinefelter syndrome until they go through puberty. In these instances, puberty may be late or incomplete. Sometimes, the condition may only be diagnosed in adulthood due to infertility. The features of KIinefelter syndrome can vary and it is important to note that not all the features described will be seen in your child.
Most boys with KIinefelter syndrome can expect to live long and healthy lives.
The following problems can also be seen in individuals with KIinefelter syndrome and need to be monitored for and treated if present:
If you notice symptoms of Klinefelter syndrome in yourself or your child, please consult a healthcare professional or specialist for further testing and diagnosis.
Klinefelter syndrome is caused by a random genetic error that results in a male having an extra X chromosome. Normally, males have one X and one Y chromosome (46,XY), but individuals with Klinefelter syndrome have an additional X chromosome (47,XXY). This extra chromosome occurs due to an error during the formation of sperm or egg cells.
The condition is not inherited and happens spontaneously during the process of cell division. In some cases, the chromosomal abnormality may occur after fertilisation, leading to mosaic klinefelter syndrome, where some cells have the typical 46, XY chromosomes, and others have 47, XXY.
Women above the age of 35 when they become pregnant have a slightly higher chance of having a child with chromosomal abnormalities, including Klinefelter syndrome. However, this increased risk is small.
There are no specific lifestyle or environmental factors that increase the likelihood of Klinefelter syndrome, as it results from random errors in cell division. Since the condition is not inherited, family history does not typically play a role.
The diagnosis of KIinefelter syndrome is made by looking at the complete set of chromosomes of the individual. This is called a karyotype. A karyotype shows the number and visual appearance of the chromosomes found in the cells of a person.
While it is not possible to cure KIinefelter syndrome, much can be done to make sure your child has the best possible outcome.
The multidisciplinary medical team will be able to address specific medical concerns and routine KIinefelter syndrome -related healthcare issues.
Below are some related medical issues and how they can be managed:
Medical issue |
Treatment |
---|---|
Developmental delay | Early intervention therapies |
Hypogonadism | Testosterone replacement |
Infertility | Assisted reproductive therapy |
Speech and occupational therapy are helpful for children and adults who experience delays in speech or challenges with motor skills.
Learning difficulties can also often be managed through tailored educational programmes and support from teachers or specialists.
Testosterone can be given in the form of injections or tablets. It is usually started from puberty and continued through adulthood.
Testosterone replacement can help to:
Although most individuals with Klinefelter syndrome are infertile, some may be able to father children through assisted reproductive techniques, such as testicular sperm extraction (TESE) combined with in vitro fertilisation (IVF).
Therapy or counselling can help manage emotional challenges, low self-esteem and social difficulties. Support groups may also provide valuable assistance.
Regular medical check-ups are essential to monitor health and address potential complications, such as osteoporosis or cardiovascular issues. Early intervention and consistent care can significantly improve outcomes for individuals with Klinefelter syndrome.
Recurrence risk is low (<1%). However, risk has been shown to increase with increasing maternal age.
Klinefelter syndrome cannot be prevented, as it occurs due to a random error during the formation of reproductive cells. This error happens when the chromosomes fail to divide properly, leading to an extra X chromosome. It is not caused by anything the parents have done before or during pregnancy.
Although the condition cannot be prevented, early diagnosis and treatment can help manage symptoms and improve quality of life. Regular medical care, hormonal therapy and support for learning or developmental challenges can make a significant difference for individuals with Klinefelter syndrome.
Support Group |
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Club Rainbow Singapore Club Rainbow Singapore supports and empowers children with chronic illnesses and their families by providing relevant compassionate services in their journey. Tel: 6377 1789 Email: contact@clubrainbow.org www.clubrainbow.org |
Download the Klinefelter Syndrome brochure.
47, XXY (klinefelter syndrome) - symptoms, causes, treatment. National Organization for Rare Disorders. (2024, July 15). https://rarediseases.org/rare-diseases/47-xxy-klinefelter-syndrome/
About klinefelter syndrome. Genome.gov. (n.d.). https://www.genome.gov/Genetic-Disorders/Klinefelter-Syndrome
Osunkoya, A. O. (2023). Klinefelter syndrome. Uropathology, 460–461. https://doi.org/10.1016/b978-0-323-65395-4.00216-5
Ross, J. L. (Ed.). (2021, September). Klinefelter syndrome (for parents) | nemours kidshealth. KidsHealth. https://kidshealth.org/en/parents/klinefelter-syndrome.html
The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth.
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