XX gonadal dysgenesis
5680651
223326912
2008-07-03T16:09:02Z
KC Panchal
3449833
/* XX GD as a form of "pure gonadal dysgenesis" */ c/e
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OMIM = 233300 |
OMIM_mult = XX gonadal dysgenesis<br>{{OMIM2|233400}} Perrault syndrome<br>{{OMIM2|306100}} Swyer syndrome |
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MeshID = D023961 |
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'''XX gonadal dysgenesis''' is a type of female [[hypogonadism]] in which no functional ovaries are present to induce [[puberty]] in an otherwise normal girl whose [[karyotype]] is found to be 46, XX. With nonfunctional ''streak'' ovaries she is low in estrogen levels (hypoestrogenic) and has high levels of [[FSH]] and [[LH]]. [[Estrogen]] and [[progesterone]] therapy is usually then commenced.
==XX GD as a form of "pure gonadal dysgenesis"==
The term “pure gonadal dysgenesis” (PGD) has been used to distinguish a group of patients from gonadal dysgenesis related to [[Turner syndrome]]. In the latter a distinct chromosomal aberration is present, while in PGD the chromosomal constellation is either 46, XX or 46, XY. Thus XX gonadal dysgenesis is also referred to as ''PGD, 46 XX'', and XY gonadal dysgenesis as ''PGD, 46, XY'' or [[Swyer syndrome]].<ref>[http://www.medscape.com/viewarticle/499501_5 Log In Problems<!-- Bot generated title -->]</ref> Patients with PGD have a normal chromosomal constellation but may have localized genetic alterations.
== Pathogenesis ==
The cause of the condition is often unclear. There are cases where abnormalities in the [[FSH-receptor]] have been reported.<ref>Aittomaki, K.; Lucena, J. L. D.; Pakarinen, P.; Sistonen, P.; Tapanainen, J.; Gromoll, J.; Kaskikari, R.; Sankila, E.-M.; Lehvaslaiho, H.; Engel, A. R.; Nieschlag, E.; Huhtaniemi, I.; de la Chapelle, A. :
Mutation in the follicle-stimulating hormone receptor gene causes hereditary hypergonadotropic ovarian failure. Cell 82: 959-968, 1995.
PMID 7553856</ref> Apparently either the germ cells do not form or interact with the gonadal ridge or undergo accelerated [[atresia]] so that at the end of childhood only a streak gonad is present, unable to induce pubertal changes. As girls' ovaries produce no important body changes before [[puberty]], there is usually no suspicion of a defect of the reproductive system until puberty fails to occur.
Familial cases of XX gonadal dysgenesis are on record.
==Perrault syndrome==
In [[1951]], Perrault reported the association of gonadal dysgenesis and deafness, now called '''Perrault syndrome'''.<ref>Perrault, M.; Klotz, B.; Housset, E. :Deux cas de syndrome de Turner avec surdi-mutite dans une meme fratrie. Bull. Mem. Soc. Med. Hop. Paris 16: 79-84, 1951.</ref>
== Diagnosis ==
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.
Evaluation of [[delayed puberty]] usually reveals the presence of pubic hair, but 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 XX chromosomes and the imaging demonstrates the presence of a uterus but no ovaries (the streak gonads are not usually seen by most imaging). At this point it is usually possible for a physician to make a diagnosis of XX gonadal dysgenesis.
== Treatment ==
The consequences to the girl with XX gonadal dysgenesis:
# Her gonads cannot make estrogen, so her breasts will not develop and her uterus will not grow and menstruate until she is given [[estrogen]]. This is often given through the skin now.
# Her gonads cannot make progesterone, so her menstrual periods will not be predictable until she is given a [[progestin]], still usually as a pill.
# Her gonads cannot produce [[ovum|eggs]] so she will not be able to conceive children naturally. A woman with a uterus but no ovaries may be able to become pregnant by implantation of another woman's fertilized egg ([[embryo transfer]]).
== Related conditions ==
The XX gonadal dysgenesis is the related to the [[Swyer syndrome]] inasmuch as both conditions have the same phenotype and clinical issues, however in Swyer syndrome the chromosome constellation is 46, XY, and thus requires gonadectomy.
In [[Turner syndrome]] there is a demonstrable abnormality in or absence of one of the sex chromosomes that is the cause of the development of gonadal dysgenesis. In contrast XX gonadal dysgenesis has a normal female chromosome situation.
Another type of XX gonadal dysgenesis is known as 46 xx gonadal dysgenesis epibulbar dermoid, which follows the similar symptoms as the regular syndrome, though it also shows signs of [[epibulbar dermoid]] (eye disorder).<ref name=NCBI>{{cite journal |author=Quayle SA, Copeland KC |title=46,XX gonadal dysgenesis with epibulbar dermoid |journal=Am. J. Med. Genet. |volume=40 |issue=1 |pages=75–6 |year=1991 |pmid=1909490 |doi=10.1002/ajmg.1320400114}}</ref><ref>{{RareDiseases|5671|46,XX Gonadal dysgenesis epibulbar dermoid}}</ref><ref>[http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=1771 ORPHANET - About rare diseases - About orphan drugs<!-- Bot generated title -->]</ref> It has been suggested to be a new type of syndrome.<ref name=NCBI />
==See also==
*[[Gonadal dysgenesis]]
==References==
<references/>
[[Category:Gynecology]]
[[Category:Genetic disorders]]