XX male syndrome: Difference between revisions
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==Presentation== |
==Presentation== |
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The appearance of XX males can fall into one of three categories: 1) males that have normal internal and external genitalia, 2) males with external ambiguities, and 3) males that have both internal and external genital ambiguities (true [[hermaphrodite]]<nowiki/>s).<ref name=":3">{{Cite journal|last=Chen|first=Harold|date=2012|title=XX Male|url=|journal=Atlas of Genetic Diagnosis and Counseling|volume=|pages=2191-2196|doi=10.1007/978-1-4614-1037-9_250|via=}}</ref> Genital ambiguities can include [[hypospadias]], [[micropenis]], and [[Clitoromegaly|clitormegaly]].<ref name=":3" /> On average, the appearance of XX males differs from that of an XY male in that they are smaller in height and weight.<ref name=":1">{{Cite journal|last=Vorona|first=Elena|last2=Zitzmann|first2=Michael|last3=Gromoll|first3=Jörg|last4=Schüring|first4=Andreas N.|last5=Nieschlag|first5=Eberhard|date=2007-09-01|title=Clinical, Endocrinological, and Epigenetic Features of the 46,XX Male Syndrome, Compared with 47,XXY Klinefelter Patients|url=https://academic.oup.com/jcem/article/92/9/3458/2597538|journal=The Journal of Clinical Endocrinology & Metabolism|language=en|volume=92|issue=9|pages=3458–3465|doi=10.1210/jc.2007-0447|issn=0021-972X}}</ref> Most XX males have small [[testes]], are [[Infertility|sterile]], and have an increase in maldescended testicles compared to XY males.<ref name=":1" /><ref name=":2">{{Cite journal|last=Lisker|first=R|last2=Flores|first2=F|last3=Cobo|first3=A|last4=Rojas|first4=F G|date=December 1970|title=A case of XX male syndrome.|url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1468937/|journal=Journal of Medical Genetics|volume=7|issue=4|pages=394–398|issn=0022-2593|pmc=PMC1468937|pmid=5501706}}</ref> |
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Symptoms usually include small [[testes]] and subjects are invariably [[infertility|sterile]]. Individuals with this condition sometimes have feminine characteristics, with varying degrees of [[gynecomastia]] but with no intra-abdominal [[Müllerian duct|Müllerian tissue]].<ref name="pmid5501706" /> According to research at the [[University of Oklahoma]] health science centers, most XX males are not stereotypically feminine and are typical boys and men<ref name="pmid5501706">{{cite journal |vauthors=Lisker R, Flores F, Cobo A, Rojas FG |title= A case of XX male syndrome |journal=J. Med. Genet. |volume= 7 |issue= 4 |pages= 394–398 |date=December 1970 |pmid=5501706 |doi=10.1136/jmg.7.4.394 |pmc=1468937}}</ref> although other reports suggest that facial hair growth is usually poor and libido is diminished, with notable exceptions.<ref>{{cite journal |vauthors=Abusheikha N, Lass A, Brinsden P|title= Case Report: XX male without SRY gene and with infertility|journal=Human Reproduction |volume= 16 |issue= 4 |pages= 717–718 |year= 2001|url=http://humrep.oxfordjournals.org/content/16/4/717.full.pdf |doi=10.1093/humrep/16.4.717 |pmid=11278224 }}</ref> |
Symptoms usually include small [[testes]] and subjects are invariably [[infertility|sterile]]. Individuals with this condition sometimes have feminine characteristics, with varying degrees of [[gynecomastia]] but with no intra-abdominal [[Müllerian duct|Müllerian tissue]].<ref name="pmid5501706" /> According to research at the [[University of Oklahoma]] health science centers, most XX males are not stereotypically feminine and are typical boys and men<ref name="pmid5501706">{{cite journal |vauthors=Lisker R, Flores F, Cobo A, Rojas FG |title= A case of XX male syndrome |journal=J. Med. Genet. |volume= 7 |issue= 4 |pages= 394–398 |date=December 1970 |pmid=5501706 |doi=10.1136/jmg.7.4.394 |pmc=1468937}}</ref> although other reports suggest that facial hair growth is usually poor and libido is diminished, with notable exceptions.<ref>{{cite journal |vauthors=Abusheikha N, Lass A, Brinsden P|title= Case Report: XX male without SRY gene and with infertility|journal=Human Reproduction |volume= 16 |issue= 4 |pages= 717–718 |year= 2001|url=http://humrep.oxfordjournals.org/content/16/4/717.full.pdf |doi=10.1093/humrep/16.4.717 |pmid=11278224 }}</ref> |
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==Pathophysiology== |
==Pathophysiology== |
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Males typically have one X chromosome and one Y chromosome in each [[diploid]] cell of their bodies. Females typically have two X chromosomes. |
Males typically have one X chromosome and one Y chromosome in each [[diploid]] cell of their bodies. Females typically have two X chromosomes. |
Revision as of 03:04, 29 November 2017
XX male syndrome | |
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Specialty | Medical genetics |
XX male syndrome (also called de la Chapelle syndrome, for Albert de la Chapelle, who characterized it in 1972[1][2]) is a rare congenital condition where an individual with a female genotype has phenotypically male characteristics that can vary between cases.[3] In 90% of these individuals the syndrome is caused by unequal crossing over between X and Y chromosomes during meiosis in the father, which results in the X chromosome containing the normally male SRY gene.[3] When this X combines with a normal X from the mother during fertilization, the result is an XX male. Less common are SRY-negative XX males which can be caused by a mutation in an autosomal or X chromosomal gene or undetected mosaicism with a Y-bearing cell line.[3]
This syndrome is diagnosed through various detection methods and occurs in approximately 1:20 000 newborn males, making it less common than Klinefelter syndrome.[4][5]
Presentation
The appearance of XX males can fall into one of three categories: 1) males that have normal internal and external genitalia, 2) males with external ambiguities, and 3) males that have both internal and external genital ambiguities (true hermaphrodites).[6] Genital ambiguities can include hypospadias, micropenis, and clitormegaly.[6] On average, the appearance of XX males differs from that of an XY male in that they are smaller in height and weight.[7] Most XX males have small testes, are sterile, and have an increase in maldescended testicles compared to XY males.[7][8]
Symptoms usually include small testes and subjects are invariably sterile. Individuals with this condition sometimes have feminine characteristics, with varying degrees of gynecomastia but with no intra-abdominal Müllerian tissue.[9] According to research at the University of Oklahoma health science centers, most XX males are not stereotypically feminine and are typical boys and men[9] although other reports suggest that facial hair growth is usually poor and libido is diminished, with notable exceptions.[10]
Pathophysiology
Males typically have one X chromosome and one Y chromosome in each diploid cell of their bodies. Females typically have two X chromosomes. XX males have two X chromosomes, with one of them containing genetic material from the Y chromosome, making them phenotypically male; they are genetically female but otherwise appear to be male.
Clinical diagnosis
- Standard XX karyotype in two tissues (with at least one, or both, containing the male SRY gene)
- Male external genitalia, sometimes showing hypospadias
- Two testes which may or may not have descended the inguinal canal. Most XX males have descended testes.
- Absence of Müllerian tissue
Treatment
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See also
- Androgen insensitivity syndrome
- Karyotype
- X chromosome, for other diseases related to the X chromosome.
- XY gonadal dysgenesis (Swyer syndrome)
References
- ^ de la Chapelle, A (January 1972). "Analytic review: nature and origin of males with XX sex chromosomes". American Journal of Human Genetics. 24 (1): 71–105. ISSN 0002-9297. PMC 1762158. PMID 4622299.
{{cite journal}}
: CS1 maint: PMC format (link) - ^ de la Chapelle, Albert (1985). Cytogenetics of the mammalian X-chromosome, Part B: Progress and topics in cytogenetics. New York: Alan Liss. pp. 75–85.
- ^ a b c Vorona, Elena; Zitzmann, Michael; Gromoll, Jörg; Schüring, Andreas N.; Nieschlag, Eberhard (2007-09-01). "Clinical, Endocrinological, and Epigenetic Features of the 46,XX Male Syndrome, Compared with 47,XXY Klinefelter Patients". The Journal of Clinical Endocrinology & Metabolism. 92 (9): 3458–3465. doi:10.1210/jc.2007-0447. ISSN 0021-972X.
- ^ Anık, Ahmet; Çatlı, Gönül; Abacı, Ayhan; Böber, Ece (2013-12). "46,XX Male Disorder of Sexual Development: A Case Report". Journal of Clinical Research in Pediatric Endocrinology. 5 (4): 258–260. doi:10.4274/Jcrpe.1098. ISSN 1308-5727. PMC 3890225. PMID 24379036.
{{cite journal}}
: Check date values in:|date=
(help)CS1 maint: PMC format (link) - ^ Ucan, Bekir; Ozbek, Mustafa; Topaloglu, Oya; Yesilurt, Ahmet; Gungunes, Askin; Demrici, Taner; Delibasi, Tunfay (July 2012). "46,XX Male Syndrome". Turkish Journal of Endocrinology and Metabolism. 17: 46–48. doi:10.4274/Tjem.2064.
- ^ a b Chen, Harold (2012). "XX Male". Atlas of Genetic Diagnosis and Counseling: 2191–2196. doi:10.1007/978-1-4614-1037-9_250.
- ^ a b Vorona, Elena; Zitzmann, Michael; Gromoll, Jörg; Schüring, Andreas N.; Nieschlag, Eberhard (2007-09-01). "Clinical, Endocrinological, and Epigenetic Features of the 46,XX Male Syndrome, Compared with 47,XXY Klinefelter Patients". The Journal of Clinical Endocrinology & Metabolism. 92 (9): 3458–3465. doi:10.1210/jc.2007-0447. ISSN 0021-972X.
- ^ Lisker, R; Flores, F; Cobo, A; Rojas, F G (December 1970). "A case of XX male syndrome". Journal of Medical Genetics. 7 (4): 394–398. ISSN 0022-2593. PMC 1468937. PMID 5501706.
{{cite journal}}
: CS1 maint: PMC format (link) - ^ a b Lisker R, Flores F, Cobo A, Rojas FG (December 1970). "A case of XX male syndrome". J. Med. Genet. 7 (4): 394–398. doi:10.1136/jmg.7.4.394. PMC 1468937. PMID 5501706.
- ^ Abusheikha N, Lass A, Brinsden P (2001). "Case Report: XX male without SRY gene and with infertility" (PDF). Human Reproduction. 16 (4): 717–718. doi:10.1093/humrep/16.4.717. PMID 11278224.