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

Swyer syndrome


Other Names:
46, XY CGD; 46, XY complete gonadal dysgenesis; 46, XY pure gonadal dysgenesis; 46, XY CGD; 46, XY complete gonadal dysgenesis; 46, XY pure gonadal dysgenesis; Gonadal dysgenesis, XY female type See More
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Swyer syndrome is a genetic condition affecting sexual organ development, classified as a disorder of sex development (DSD). In Swyer syndrome, people with one X chromosome and one Y chromosome, normally present in males, are born with female external genitalia and underdeveloped gonads (ovaries or testes) known as streak gonads. Most people with Swyer syndrome are raised as females. Adolescents with this condition do not go through normal puberty and are infertile. Some cases of Swyer syndrome are caused by genetic alterations (mutations) in one of several genes, but in some cases the cause is unknown. The inheritance pattern depends on the responsible gene. This condition is diagnosed based on the chromosome results, clinical examination, and imaging studies. Treatment includes removal of streak gonads to prevent cancer and hormone replacement therapy from puberty onward. While women with Swyer syndrome are infertile, they may become pregnant with the use of donated eggs.[1][2][3]
Last updated: 4/23/2020
The following list includes the most common signs and symptoms in people with Swyer syndrome. These features may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe. This list also does not include every symptom or feature that has been described in Swyer syndrome.[4][2]

Signs and symptoms may include:
  • Female external genitals
  • 46,XY chromosomes
  • Delayed or absent puberty
  • Absent menstrual periods (primary amenorrhea)
  • Undeveloped ovaries or testes (streak gonads)
Most people with Swyer syndrome are raised and identify as female. They may have no symptoms until adolescence when they do not go through puberty and or start their periods. Hormone replacement therapy can help to develop secondary sexual characteristics such as breasts, pubic hair, and a regular menstrual cycle. People with Swyer syndrome are infertile, but may be able to get pregnant through egg donation and artificial reproductive technologies.[4][2][3]
Last updated: 4/24/2020

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 14 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Hypogonadotropic hypogonadism 0000044
Male pseudohermaphroditism 0000037
Polycystic ovaries 0000147
Testicular dysgenesis 0008715
1%-4% of people have these symptoms
Ambiguous genitalia
Ambiguous external genitalia
Ambiguous external genitalia at birth
Intersex genitalia
[ more ] 		0000062
Percent of people who have these symptoms is not available through HPO
Abnormality of female external genitalia
Abnormal female external genitalia
0000055
Absence of secondary sex characteristics 0008187
Elevated circulating follicle stimulating hormone level 0008232
Elevated circulating luteinizing hormone level 0011969
Gonadal dysgenesis 0000133
Gonadoblastoma 0000150
Primary amenorrhea 0000786
Sex reversal 0012245
Tall stature
Increased body height
0000098
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Last updated: 7/1/2020
About 10-20% of cases are caused by genetic alterations (mutations) in the SRY gene.[2][3] At least ten different other genes have been associated with Swyer syndrome. In many cases, the cause of Swyer syndrome remains unknown.[3][5]  
Last updated: 4/24/2020
In many cases, Swyer syndrome occurs as the result of a new genetic change and is not inherited in families. In some families, Swyer syndrome is inherited. The inheritance pattern depends on which gene is identified as the cause for the condition in the individual.[4][2][3] 
Last updated: 4/24/2020
Swyer syndrome is diagnosed based on the medical history, clinical examination, presence of characteristic features, chromosome results, and imaging studies such as a MRI or CT scan. Often people with this condition are not diagnosed until adolescence or adulthood due to delayed puberty, not having menstrual cycles, or infertility. In some cases, Swyer syndrome is diagnosed at birth based on a prenatal test and ultrasound findings.[1][2][3]
Last updated: 4/24/2020
The treatment of a person with Swyer syndrome may depend on the specific characteristics that each person has. Some people need surgery to repair the external genitalia and to create and/or enlarge the vagina. Hormone replacement therapy (HRT) is typically needed from puberty onward and usually includes estrogen and progesterone.[6] In addition to helping with normal development of secondary sexual characteristics, HRT can help prevent bone loss and thinning (osteoporosis) later in life. Abdominal dysgenetic gonads (testes or ovaries with abnormal development) or streak gonads, which are common in people with Swyer syndrome, are at increased risk for gonadal tumors such as gonadoblastoma and should be surgically removed. Although women with Swyer syndrome are infertile, they may become pregnant and carry to term through egg donation.[6]
Last updated: 11/16/2015

Treatment for Swyer syndrome includes surgery to remove undeveloped gonads (streak gonads) and hormone replacement therapy during adolescence. Streak gonads are removed as soon as possible because of the risk of them becoming cancerous. Women with Swyer syndrome are infertile, but pregnancy is possible through egg donation and artificial reproductive technologies.[1][2][3]

Specialists who might be involved in the care of someone with Swyer syndrome include:
  • Endocrinologist (specialist in hormones)
  • Gynecologist
  • Psychologist 
Last updated: 4/24/2020
It has been estimated that 1 in 50,000 to 1 in 100,000 people are born with Swyer syndrome.[4][3] The exact incidence is unknown.
Last updated: 4/24/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

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
The differential diagnosis should include hypergonadotropic ovarian dysgenesis (46,XX GD) and all forms of syndromic 46,XY CGD (for example, Frasier syndrome, campomelic dysplasia and 46,XY DSD with adrenal insufficiency; see these terms).
Visit the Orphanet disease page for more information.

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.

Where to Start

  • Genetics Home Reference (GHR) contains information on Swyer syndrome. This website is maintained by the National Library of Medicine.
  • 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.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • 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.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • 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 Swyer 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

  • Is it possible for someone with Swyer syndrome to naturally start their period at a typical age (13)? See answer

  • Can women with Swyer syndrome experience orgasms? See answer

  • Is it possible for a patient with Swyer syndrome to get pregnant? If so, what methods should be used to ensure a successful pregnancy? See answer

  • I was born without ovaries. I have everything else that a normal woman has but I have streaks where ovaries would be. I was diagnosed when I was 15. My doctor put me on triphasil and soon after I started showing signs of puberty. None of my doctors seem to know about this condition. I am now 31. I am wondering if I should opt to have my streaks removed and if I should be on some other form of estrogen. I have very little breast development. See answer


  1. Mayur P, Parikshaa G, Anil B, Shalini G, Arvind R. 'Size does matter': Prophylactic gonadectomy in a case of Swyer syndrome. J Gynecol Obstet Hum Reprod. 2019; 48(4):283-286. https://pubmed.ncbi.nlm.nih.gov/30690088.
  2. Meyer KF, Freitas Filho LG, Silva KI, Trauzcinsky PA, Reuter C, Souza MBM. The XY female and SWYER syndrome. Urol Case Rep. 2019;26:100939. Published 2019 Jun 7.. 2019; 26:100939. https://pubmed.ncbi.nlm.nih.gov/31275808.
  3. Banoth M, Naru RR, Inamdar MB, Chowhan AK. Familial Swyer syndrome: a rare genetic entity. Gynecol Endocrinol. 2018; 34(5):389-393. https://pubmed.ncbi.nlm.nih.gov/29069951.
  4. Swyer syndrome. National Organization for Rare Disorders (NORD). Updated 2019; https://rarediseases.org/rare-diseases/swyer-syndrome/.
  5. 46,XY Sex reversal 1; SRXY1; phenotypic series. Online Mendelian Inheritance in Man (OMIM). Updated Aug 20, 2019; https://omim.org/entry/400044.
  6. Harry Ostrer. 46,XY Disorder of Sex Development and 46,XY Complete Gonadal Dysgenesis. GeneReviews. September 15, 2009; http://www.ncbi.nlm.nih.gov/books/NBK1547/. Accessed 3/30/2012.