National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

47, XXY

Not a rare disease Not a rare disease
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People with 47, XXY have an extra chromosome. The X and Y chromosomes are the sex chromosomes. Females usually have two X chromosomes (46, XX) and males usually have one X and one Y chromosome (46, XY). People with 47, XXY have two X chromosomes and one Y chromosome. Some people with 47, XXY may have no noticeable signs or symptoms (features) or only mild features. Others may have more moderate to severe features.[1][2] Common symptoms of 47, XXY include low testosterone, infertility, speech and language problems, and learning difficulties.[1][2][3] Although the majority of people with 47, XXY identify as males (gender identity), some people with 47, XXY identify as female, intersex, transgender, or prefer not to identify with a gender at all.[2] A diagnosis of 47, XXY may be suspected by signs and symptoms and confirmed by genetic testing. Diagnosis may also be made during prenatal genetic testing or infertility testing.[1][2][3]

People with 47, XXY are at an increased risk of developing diabetes, metabolic syndrome, osteoporosis, cardiovascular diseases, autoimmmune disorders, and certain mental health problems. Regular screening for these health problems is suggested. Although most males with 47, XXY are infertile, many produce sperm and may be able to conceive with assisted reproduction. A discussion about testosterone therapy with a pediatric endocrinologist is advised, even if the person with 47, XXY does not identify as male. Other features of 47, XXY may be managed by early intervention, speech therapy, occupational therapy, physical therapy, extra help in school, counseling, and social skills training.[2][3] 

Less commonly, some woman are found to be 47, XXY. In most of these cases, a change or mutation has been found in a gene that helps control male sexual development. Most often, women with 47, XXY are infertile, but in a few cases they have had children naturally.[4][5] 

Last updated: 10/18/2017
Some people with 47, XXY do not have any noticeable signs or symptoms (features) associated with the chromosome variation. Others may have features that range from mild to severe.[1][2] 

In general male babies and young boys with 47, XXY are not very different from babies and young boys with 46, XY. Some may have slightly longer legs, weaker muscles, delayed development of motor skills, and learning and/or language problems. Puberty and adulthood is when differences may become more clear. One of the most common features shared by males with 47, XXY is hypogonadism, which means the testes do not produce enough testosterone. Other than a small period in infancy, testosterone production is not important until puberty. Low testosterone may cause some boys with 47, XXY to have delayed or incomplete puberty, as well as may worsen concentration, mood, and behavioral problems. For others, the low testosterone may not cause noticeable symptoms until adulthood when low sexual drive and tiredness may develop and continue to worsen with age. For some men, infertility caused by no or low sperm count may be the first detected symptom.[1][2] 

Many but not all males with 47, XXY may develop signs and symptoms (features) of Klinefelter syndrome (KS) during their teen and adult years. KS is the name of a collection of features that include decreased testosterone production (primary hypogonadism), small testes, enlarged breast tissue (gynecomastia), tall stature, long legs, wide hips, learning disabilities, behavioral problems, and social relational problems. KS can also be caused by other sex chromosome variations.[1][2]
Last updated: 10/18/2017

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to 47, XXY. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with 47, XXY. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for 47, XXY:
    Infertility Family Research Registry (IFRR)
     

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • PubMed is a searchable database of medical literature and lists journal articles that discuss 47, XXY. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Bonomi M, Rochira V, Pasquali D, Balercia G, Jannini EA, Ferlin A; Klinefelter ItaliaN Group (KING). Klinefelter syndrome (KS): genetics, clinical phenotype and hypogonadism. Journal of Endocrinological Investigation. 2017; 40(2):123-4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5269463/.
  2. 47 XXY Frequently Asked Questions. Association for X and Y Chromosome Variations (AXYS). 2016; https://genetic.org/variations/faq/.
  3. Chang S, Skakkebæk A, Gravholt CH. Klinefelter Syndrome and medical treatment: hypogonadism and beyond. Hormones (Athens). Oct-Dec 2015; 14(4):531-48. http://www.hormones.gr/8592/article/article.html.
  4. Lin B, Tan F, Xu H, Wang P, Tang Q, Zhu Y, Kong X, Hu L. De novo structure variations of the Y chromosome in a 47,XXY female with ovarian failure: a case report. Cytogenet Genome Res. 2014; 143(4):221-4. http://www.ncbi.nlm.nih.gov/pubmed/25227289.
  5. Fruhmesser A. Kotzot D. Chromosomal variants in Klinefelter syndrome. Sexual Development. 2011; 5:109-123. http://www.ncbi.nlm.nih.gov/pubmed/21540567.