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 XXX syndrome

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Other Names:
Trisomy X; Triple X syndrome; Triple-X female; Trisomy X; Triple X syndrome; Triple-X female; XXX syndrome; Triple-X chromosome syndrome; Triplo X syndrome See More
Categories:
This disease is grouped under:
47 XXX syndrome, also called trisomy X or triple X syndrome, is characterized by the presence of an additional (third) X chromosome in each of a female's cells (which normally have two X chromosomes). An extra copy of the X chromosome is associated with tall stature, learning problems, and other features in some girls and women. Seizures or kidney abnormalities occur in about 10 percent of affected females. 47 XXX syndrome is usually caused by a random event during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes.[1] Treatment typically focuses on specific symptoms, if present.[2] Some females with 47 XXX syndrome have an extra X chromosome in only some of their cells; this is called 46,XX/47,XXX mosaicism.[1]
Last updated: 12/7/2016
Many women with 47 XXX syndrome have no symptoms or only mild symptoms. In other cases, symptoms may be more pronounced.[2] Females with 47 XXX syndrome may be taller than average, but the condition usually does not cause unusual physical features. Minor physical findings can be present in some individuals and may include epicanthal folds, hypertelorism (widely spaced eyes), upslanting palpebral fissures, clinodactyly, overlapping digits (fingers or toes), pes planus (flat foot), and pectus excavatum.[3] The condition is associated with an increased risk of learning disabilities and delayed development of speech and language skills. Delayed development of motor skills (such as sitting and walking), weak muscle tone (hypotonia), and behavioral and emotional difficulties are also possible, but these characteristics vary widely among affected girls and women. Seizures or kidney abnormalities occur in about 10 percent of affected females. Most females with the condition have normal sexual development and are able to conceive children.[2][1]
Last updated: 12/7/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 21 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormality of chromosome segregation 0002916
30%-79% of people have these symptoms
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment
[ more ] 		0100543
Epicanthus
Eye folds
Prominent eye folds
[ more ] 		0000286
Global developmental delay 0001263
Muscular hypotonia
Low or weak muscle tone
0001252
Specific learning disability 0001328
Tall stature
Increased body height
0000098
5%-29% of people have these symptoms
Anxiety
Excessive, persistent worry and fear
0000739
Attention deficit hyperactivity disorder
Attention deficit
Attention deficit disorder
Attention deficit-hyperactivity disorder
Attention deficits
Childhood attention deficit/hyperactivity disorder
[ more ] 		0007018
Depressivity
Depression
0000716
Hip dysplasia 0001385
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Joint hyperflexibility
Joints move beyond expected range of motion
0005692
Multicystic kidney dysplasia 0000003
Pectus excavatum
Funnel chest
0000767
Renal hypoplasia/aplasia
Absent/small kidney
Absent/underdeveloped kidney
[ more ] 		0008678
Secondary amenorrhea
Previous menstrual periods stop
0000869
Seizure 0001250
Tremor 0001337
Upslanted palpebral fissure
Upward slanting of the opening between the eyelids
0000582
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Last updated: 7/1/2020
Most cases of 47 XXX syndrome are not inherited. The chromosomal change usually occurs as a random event during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of the X chromosome as a result of nondisjunction. If one of these reproductive cells contributes to the genetic makeup of a child, the child will have an extra X chromosome in each of the body's cells. 46,XX/47,XXX mosaicism is also not inherited. It occurs as a random event during cell division in the early development of an embryo. As a result, some of an affected person's cells have two X chromosomes (46,XX), and other cells have three X chromosomes (47,XXX).[1]

Transmission of an abnormal number of X chromosomes from women with 47 XXX syndrome is rare, although it has been reported. Some reports suggest a <5% increased risk for a chromosomally abnormal pregnancy, and other more recent reports suggest that <1% may be more accurate. These risks are separate from the risks of having a chromosomally abnormal pregnancy due to maternal age or any other factors. Furthermore, these risks generally apply only to women with non-mosaic 47 XXX syndrome, as mosaicism may increase the risk of passing on an abnormal number of X chromosomes and potential outcomes.[3] Each individual with 47 XXX syndrome who is interested in learning about their own risks to have a child with a chromosome abnormality or other genetic abnormality should speak with their healthcare provider or a genetics professional.
Last updated: 12/7/2016
47 XXX syndrome may first be suspected based on the presence of certain developmental, behavioral or learning disabilities in an individual. The diagnosis can be confirmed with chromosomal analysis (karyotyping), which can be performed on a blood sample. This test would reveal the presence of an extra X chromosome in body cells. 47 XXX syndrome may also be identified before birth (prenatally), based on chromosomal analysis performed on a sample taken during an amniocentesis or by a chorionic villus sampling (CVS) procedure.[4] However, in these cases, confirmation testing with a test called FISH, which gives more details of the chromosomes, is recommended in order to evaluate the fetus for mosaicism (when only some of the cells have the extra X chromosome).[5]
Last updated: 12/7/2016

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
There is no cure for 47 XXX syndrome, and there is no way to remove the extra X chromosome that is present in an affected individual's cells. Management of the condition varies and depends on several factors including the age at diagnosis, the specific symptoms that are present, and the overall severity of the disorder in the affected individual. Recommendations include:[4][6]
  • Early intervention services  for infants and children that are diagnosed with the condition. Evidence suggests that children with 47 XXX syndrome are very responsive to early intervention services and treatment. These services may include speech, occupational, physical or developmental therapy, starting in the early months of life or as soon as needs are identified.
  • Periodic screenings throughout childhood: Specific recommendations include developmental assessment by 4 months of age to evaluate muscle tone and strength; language and speech assessment by 12 months of age;  pre-reading assessment during preschool years; and an assessment of additional learning disabilities as well as social and emotional problems. 
  • Educational assistance. Receiving educational help to learn techniques and strategies to be successful in school and daily life.
  • Supportive environment and counseling. Girls with triple X syndrome may be more prone to anxiety, as well as behavior and emotional problems. It is important to have a supportive environment and psychological counseling which may help teaching the family how to demonstrate love and encouragement, and discourage behaviors that might negatively impact learning and social functioning.
  • Assistance and support in daily functioning. If there is developmental delays, this assistance and support may include help with activities of daily living, social opportunities and employment.
It is also recommended that infants and children with 47 XXX syndrome receive kidney and heart evaluations to detect possible abnormalities. Adolescent and adult women who have late periods, menstrual abnormalities, or fertility issues should be evaluated for primary ovarian failure (POF). Additional treatment for this disorder depends on the specific signs and symptoms present in the affected individual.[4]
Last updated: 12/7/2016

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis prior to definitive karyotype results includes fragile X syndrome, tetrasomy X, pentasomy X, and Turner syndrome mosaicism (see these terms).
Visit the Orphanet disease page for more information.

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 XXX syndrome. 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.

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

Organizations Providing General Support

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.

Where to Start

  • Genetics Home Reference (GHR) contains information on 47 XXX syndrome. This website is maintained by the National Library of Medicine.
  • The Mayo Clinic Web site provides further information on 47 XXX syndrome.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
  • Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about 47 XXX syndrome.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss 47 XXX syndrome. 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. Submit a new question

  • Hello my daughter has trisomy x and so far is doing well except for a being significantly underweight. Is there a correlation with difficulty to gain weight and trisomy x? See answer

  • My elementary school-aged granddaughter was recently diagnosed with 47 XXX syndrome. In addition, she has Attention deficit hyperactivity disorder (ADHD). I was wondering what the possible relationship might be, if any, between ADHD and the behavior problems associated with 47 XXX syndrome. Is it possible that her behavioral concerns are resulting from her chromosome abnormality and not ADHD? See answer

  • I was wondering if there is a treatment or if there are any in development. Also, is there still research being done about triple X? Are there any tests that need to be done besides a blood test? Are there any physical or mental characteristics associated with the disorder? See answer

  • Does 47 XXX syndrome affect fertility? What are the chances for a woman with 47 XXX syndrome to have a child with the same condition? See answer


  1. Triple X syndrome. Genetics Home Reference. June 2014; http://ghr.nlm.nih.gov/condition/triple-x-syndrome.
  2. Triple X syndrome. Mayo Clinic. http://www.mayoclinic.org/diseases-conditions/triple-x-syndrome/basics/definition/con-20033705?p=1.
  3. Nicole R Tartaglia, Susan Howell, Ashley Sutherland, Rebecca Wilson, Lennie Wilson. A review of trisomy X (47,XXX). Orphanet Journal of Rare Diseases. May 2010; 11:5-8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883963/?tool=pubmed.
  4. Samango-Sprouse C. Trisomy X. National Organization for Rare Disorders (NORD). 2014; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1024/viewAbstract.
  5. Tartaglia NR, Howell S, Sutherland A, Wilson R, Wilson L. A review of trisomy X (47,XXX). Orphanet J Rare Dis. May 2010; 11:5-8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883963/?tool=pubmed. Accessed 9/24/2014.
  6. Triple X syndrome. Mayo Clinic. December, 2015; https://www.mayoclinic.org/diseases-conditions/triple-x-syndrome/diagnosis-treatment/drc-20350981.