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| {{SI}} | | __NOTOC__ |
| | {{Swyer's syndrome}} |
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| {{CMG}} | | {{SK}} XY gonadal dysgenesis |
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| | ==[[Swyer's syndrome overview|Overview]]== |
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| {{EH}}
| | ==[[Swyer's syndrome historical perspective|Historical Perspective]]== |
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| == Overview == | | ==[[Swyer's syndrome classification|Classification]]== |
| '''Swyer syndrome''', or '''XY gonadal dysgenesis''', is a type of female [[hypogonadism]] in which no functional [[gonad]]s are present to induce [[puberty]] in an otherwise normal girl whose [[karyotype]] is then found to be XY. Her [[gonad]]s are found to be nonfunctional streaks. [[Estrogen]] and [[progesterone]] therapy is usually then commenced. The gonads are normally removed surgically because they do not function and may develop [[cancer]].
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| == Swyer syndrome as a form of "pure gonadal dysgenesis"== | | ==[[Swyer's syndrome pathophysiology|Pathophysiology]]== |
| There are several forms of [[gonadal dysgenesis]]. The term “pure gonadal dysgenesis” (PGD) has been used to describe conditions of with normal sets of sex chromosomes (e.g., 46,XX or 46,XY), as opposed to those whose gonadal dysgenesis results from missing all or part of the second sex chromosome. The latter group includes those with [[Turner syndrome]] (e.g., 45,X) and its variants, as well as those with [[mixed gonadal dysgenesis]] and a mixtures of cell lines, some containing a Y chromosome (e.g., 46,XY/45,X).
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| Thus Swyer syndrome is referred to as PGD, 46,XY, and [[XX gonadal dysgenesis]] as PGD, 46,XX.<ref>http://www.medscape.com/viewarticle/499501_5</ref> Patients with PGD have a normal chromosomal constellation but may have defects of a specific gene on a chromosome.
| | ==[[Swyer's syndrome causes|Causes]]== |
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| == Pathogenesis == | | ==[[Swyer's syndrome differential diagnosis|Differentiating Swyer's syndrome from other Diseases]]== |
| The first known step of [[sexual differentiation]] of a normal XY fetus is the development of [[testes]]. The early stages of testicular formation in the second month of gestation require the action of several [[gene]]s, of which one of the earliest and most important is ''[[SRY]]'', the "sex-determining region of the Y chromosome".
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| Mutations of SRY account for most cases of Swyer syndrome. When this gene is defective, [[testes]] fail to develop in an XY (genetically male) fetus. Without testes, no [[testosterone]] or [[antimullerian hormone]] are produced. Without [[testosterone]] the external [[genitalia]] fail to [[virilization|virilize]], resulting in female genitalia. Without testosterone, the [[wolffian duct]]s fail to develop, so no internal male organs are formed. Without [[antimullerian hormone|AMH]] the [[mullerian duct]]s develop into normal internal female organs ([[uterus]], [[fallopian tube]]s, [[cervix]], [[vagina]]).
| | ==[[Swyer's syndrome epidemiology and demographics|Epidemiology and Demographics]]== |
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| A baby girl is born who is normal in all anatomic respects except that she has nonfunctional [[streak gonads]] instead of [[ovary|ovaries]] or testes. As girls' ovaries normally produce no important body changes before [[puberty]], a defect of the reproductive system typically remains unsuspected in girls with Swyer syndrome until puberty fails to occur.
| | ==[[Swyer's syndrome risk factors|Risk Factors]]== |
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| == Diagnosis == | | ==[[Swyer's syndrome natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
| Because of the inability of the streak gonads to produce [[sex hormone]]s (both [[estrogen]]s and [[androgen]]s), most of the [[secondary sex characteristic]]s do not develop. This is especially true of estrogenic changes such as breast development, widening of the pelvis and hips, and [[menstrual cycle|menstrual periods]]. Because the [[adrenal gland]]s can make limited amounts of androgens and are not affected by this syndrome, most of these girls will develop pubic hair, though it often remains sparse.
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| Evaluation of [[delayed puberty]] usually reveals elevation of [[gonadotropin]]s, indicating that the pituitary is providing the signal for puberty but the gonads are failing to respond. The next steps of the evaluation usually include checking a [[karyotype]] and imaging of the pelvis. The karyotype reveals XY chromosomes and the imaging demonstrates the presence of a uterus but no ovaries (the streak gonads are not usually seen by most imaging). Although an XY karyotype can also indicate a girl with complete [[androgen insensitivity syndrome]], the absence of breasts, and the presence of a uterus and pubic hair exclude the possibility. At this point it is usually possible for a physician to make a diagnosis of Swyer syndrome.
| | ==Diagnosis== |
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| == Treatment ==
| | [[Swyer's syndrome history and symptoms|History and Symptoms]] | [[Swyer's syndrome physical examination|Physical Examination]] | [[Swyer's syndrome laboratory findings|Laboratory Findings]] | [[Swyer's syndrome x ray|X Ray]] | [[Swyer's syndrome CT|CT]] | [[Swyer's syndrome MRI|MRI]] | [[Swyer's syndrome echocardiography or ultrasound|Echocardiography or Ultrasound]] | [[Swyer's syndrome other imaging findings|Other Imaging Findings]] | [[Swyer's syndrome other diagnostic studies|Other Diagnostic Studies]] |
| The consequences of streak gonads to a woman with Swyer syndrome:
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| # Gonads cannot make estrogen, so the breasts will not develop and the uterus will not grow and menstruate until [[estrogen]] is administered. This is often given through the skin now.
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| # Gonads cannot make progesterone, so menstrual periods will not be predictable until [[progestin]] is administered, still usually as a pill.
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| # Gonads cannot produce [[ovum|eggs]] so conceiving children naturally is not possible. A woman with a uterus but no ovaries may be able to become pregnant by implantation of another woman's fertilized egg ([[embryo transfer]]).
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| # Streak gonads with Y chromosome-containing cells have a high likelihood of developing cancer, especially [[gonadoblastoma]]. Streak gonads are usually removed within a year or so of diagnosis since the cancer can begin during infancy.
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| == Gonadal dysgenesis and other similar or related conditions == | | ==Treatment== |
| Swyer syndrome results from a failure of one of the earliest stages of differentiation of a genetic male: translation of the SRY gene to initiate testicular development. This syndrome represents one [[phenotype|phenotypic]] result of a failure of the gonads to develop properly, and hence is part of a class of conditions termed [[gonadal dysgenesis]]. There are many forms of gonadal dysgenesis. As more and more specific genetic and molecular causes of gonadal dysgenesis become understood and defined, the eponymic terms such as Swyer syndrome are losing precision as diagnostic terms, though they still refer to a specific phenotype for purposes of medical recognition and management.
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| Swyer syndrome is an example of a condition in which an externally unambiguous female body carries dysgenetic, atypical, or abnormal gonads. Other examples include complete [[androgen insensitivity syndrome]], partial [[X chromosome]] deletions, [[lipoid congenital adrenal hyperplasia]], and [[Turner syndrome]]. | | [[Swyer's syndrome medical therapy|Medical Therapy]] | [[Swyer's syndrome surgery|Surgery]] | [[Swyer's syndrome prevention|Prevention]] | [[Swyer's syndrome cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Swyer's syndrome future or investigational therapies|Future or Investigational Therapies]] |
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| =="The Way I Like To Do It ..." Tips and Tricks From Clinicians Around The World== | | ==Case Studies== |
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| ==References==
| | [[Swyer's syndrome case study one|Case #1]] |
| <references/>
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| http://en.wikipedia.org/w/index.php?title=Swyer_syndrome&action=edit
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| == External links == | | == External links == |
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| * [http://www-personal.umd.umich.edu/~jcthomas/JCTHOMAS/1997%20Case%20Studies/N.Justus.html Gonadal dysgenesis] | | * [http://www-personal.umd.umich.edu/~jcthomas/JCTHOMAS/1997%20Case%20Studies/N.Justus.html Gonadal dysgenesis] |
| * [http://www.acta-endo.ro/archive/2006/numarul4/abstracts/Complete%20Gonadal%20Dysgenesis%20With%20XY%20Chromosomal%20Constitution.html Swyer Syndrome Case Report]
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| [[de:Swyer-Syndrom]] | | [[de:Swyer-Syndrom]] |
| [[pl:zespół Swyera]] | | [[pl:zespół Swyera]] |
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| | {{WH}} |
| | {{WS}} |
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| == Acknowledgements ==
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| The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.
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| List of contributors:
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| == Suggested Reading and Key General References ==
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| == Suggested Links and Web Resources ==
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| == For Patients ==
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| ----
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| {{SIB}}
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| [[Category:Intersexuality]] | | [[Category:Intersexuality]] |
| [[Category:Endocrinology]] | | [[Category:Endocrinology]] |
| [[Category:Gynecology]] | | [[Category:Gynecology]] |
| [[Category:Genetic Disease]] | | [[Category:Genetic Disease]] |
| [[Category:DiseaseState]] | | [[Category:Disease]] |