GTS5:Klinefelter syndrome: Difference between revisions
| [pending revision] | [pending revision] |
No edit summary |
No edit summary |
||
| Line 39: | Line 39: | ||
==Epidemiology/Prevalence== | ==Epidemiology/Prevalence== | ||
The incidence of KS is approximately 1 in 500 to 1000 male births.<ref name=":0" /><ref>{{Cite journal|last=Berglund|first=Agnethe|last2=Stochholm|first2=Kirstine|last3=Gravholt|first3=Claus Højbjerg|date=2020-06|title=The epidemiology of sex chromosome abnormalities|url=https://pubmed.ncbi.nlm.nih.gov/32506765|journal=American Journal of Medical Genetics. Part C, Seminars in Medical Genetics|volume=184|issue=2|pages=202–215|doi=10.1002/ajmg.c.31805|issn=1552-4876|pmid=32506765}}</ref> However, some studies suggest the prevalence could be as high as 1:600 due to under diagnosis, as many individuals have mild or unnoticed symptoms.<ref>{{Cite journal|last=Bojesen|first=Anders|last2=Juul|first2=Svend|last3=Gravholt|first3=Claus Højbjerg|date=2003-02|title=Prenatal and postnatal prevalence of Klinefelter syndrome: a national registry study|url=https://pubmed.ncbi.nlm.nih.gov/12574191|journal=The Journal of Clinical Endocrinology and Metabolism|volume=88|issue=2|pages=622–626|doi=10.1210/jc.2002-021491|issn=0021-972X|pmid=12574191}}</ref> Only about 10% of cases are diagnosed before puberty, and many individuals remain undiagnosed. The median age of diagnosis is in the mid-30s.<ref name=":0" /> There is a significant association with advanced maternal age: around 50-60% of cases result from maternal non-disjunction during meiosis I, while the remaining cases arise from paternal non-disjunction during meiosis II or postzygotic mitotic errors, which are not associated with parental age.<ref>{{Cite journal|last=Thomas|first=N. S.|last2=Hassold|first2=T. J.|date=2003|title=Aberrant recombination and the origin of Klinefelter syndrome|url=https://pubmed.ncbi.nlm.nih.gov/12926525|journal=Human Reproduction Update|volume=9|issue=4|pages=309–317|doi=10.1093/humupd/dmg028|issn=1355-4786|pmid=12926525}}</ref> | The incidence of KS is approximately 1 in 500 to 1000 male births.<ref name=":0" /><ref>{{Cite journal|last=Berglund|first=Agnethe|last2=Stochholm|first2=Kirstine|last3=Gravholt|first3=Claus Højbjerg|date=2020-06|title=The epidemiology of sex chromosome abnormalities|url=https://pubmed.ncbi.nlm.nih.gov/32506765|journal=American Journal of Medical Genetics. Part C, Seminars in Medical Genetics|volume=184|issue=2|pages=202–215|doi=10.1002/ajmg.c.31805|issn=1552-4876|pmid=32506765}}</ref> However, some studies suggest the prevalence could be as high as 1:600 due to under diagnosis, as many individuals have mild or unnoticed symptoms.<ref>{{Cite journal|last=Bojesen|first=Anders|last2=Juul|first2=Svend|last3=Gravholt|first3=Claus Højbjerg|date=2003-02|title=Prenatal and postnatal prevalence of Klinefelter syndrome: a national registry study|url=https://pubmed.ncbi.nlm.nih.gov/12574191|journal=The Journal of Clinical Endocrinology and Metabolism|volume=88|issue=2|pages=622–626|doi=10.1210/jc.2002-021491|issn=0021-972X|pmid=12574191}}</ref> Only about 10% of cases are diagnosed before puberty, and many individuals remain undiagnosed. The median age of diagnosis is in the mid-30s.<ref name=":0" /> There is a significant association with advanced maternal age: around 50-60% of cases result from maternal non-disjunction during meiosis I, while the remaining cases arise from paternal non-disjunction during meiosis II or postzygotic mitotic errors, which are not associated with parental age.<ref>{{Cite journal|last=Thomas|first=N. S.|last2=Hassold|first2=T. J.|date=2003|title=Aberrant recombination and the origin of Klinefelter syndrome|url=https://pubmed.ncbi.nlm.nih.gov/12926525|journal=Human Reproduction Update|volume=9|issue=4|pages=309–317|doi=10.1093/humupd/dmg028|issn=1355-4786|pmid=12926525}}</ref> | ||
KS also carriers an increased risk for breast cancer and extragonadal germ cell tumors. Males with KS have a 20-30-fold increased risk of developing breast cancer over the average male population risk of approximately 1 in 726.<ref>{{Cite journal|last=Swerdlow|first=Anthony J.|last2=Schoemaker|first2=Minouk J.|last3=Higgins|first3=Craig D.|last4=Wright|first4=Alan F.|last5=Jacobs|first5=Patricia A.|last6=UK Clinical Cytogenetics Group|date=2005-08-17|title=Cancer incidence and mortality in men with Klinefelter syndrome: a cohort study|url=https://pubmed.ncbi.nlm.nih.gov/16106025|journal=Journal of the National Cancer Institute|volume=97|issue=16|pages=1204–1210|doi=10.1093/jnci/dji240|issn=1460-2105|pmid=16106025}}</ref> There is also an increased incidence of mediastinal germ cell tumors (M-GCTs) in KS patients, which can lead to precocious puberty due to human chorionic gonadotropin (hCG)-producing M-GCTs.<ref>{{Cite journal|last=Hasle|first=H.|last2=Jacobsen|first2=B. B.|last3=Asschenfeldt|first3=P.|last4=Andersen|first4=K.|date=1992-10|title=Mediastinal germ cell tumour associated with Klinefelter syndrome. A report of case and review of the literature|url=https://pubmed.ncbi.nlm.nih.gov/1425792|journal=European Journal of Pediatrics|volume=151|issue=10|pages=735–739|doi=10.1007/BF01959079|issn=0340-6199|pmid=1425792}}</ref><ref>{{Cite journal|last=Völkl|first=Thomas M. K.|last2=Langer|first2=Thorsten|last3=Aigner|first3=Thomas|last4=Greess|first4=Holger|last5=Beck|first5=Jörn D.|last6=Rauch|first6=Anita M.|last7=Dörr|first7=Helmuth G.|date=2006-03-01|title=Klinefelter syndrome and mediastinal germ cell tumors|url=https://pubmed.ncbi.nlm.nih.gov/16470792|journal=American Journal of Medical Genetics. Part A|volume=140|issue=5|pages=471–481|doi=10.1002/ajmg.a.31103|issn=1552-4825|pmid=16470792}}</ref> The pathophysiology is unclear, but is thought to be related to genes the extra X chromosome.<ref>{{Cite journal|last=Rapley|first=E. A.|last2=Crockford|first2=G. P.|last3=Teare|first3=D.|last4=Biggs|first4=P.|last5=Seal|first5=S.|last6=Barfoot|first6=R.|last7=Edwards|first7=S.|last8=Hamoudi|first8=R.|last9=Heimdal|first9=K.|date=2000-02|title=Localization to Xq27 of a susceptibility gene for testicular germ-cell tumours|url=https://pubmed.ncbi.nlm.nih.gov/10655070|journal=Nature Genetics|volume=24|issue=2|pages=197–200|doi=10.1038/72877|issn=1061-4036|pmid=10655070}}</ref> | |||
==Genetic Abnormalities: Germline== | ==Genetic Abnormalities: Germline== | ||
Put your text here and fill in the table <span style="color:#0070C0">(''Instructions: Describe germline alteration(s) that cause the syndrome. In the notes, include additional details about most common mutations including founder mutations, mechanisms of molecular pathogenesis, alteration-specific prognosis and any other important genetics-related information. If multiple causes of the syndrome, include relative prevalence of genetic contributions to that syndrome. Please include references throughout the table. Do not delete the table.'')</span> | Put your text here and fill in the table <span style="color:#0070C0">(''Instructions: Describe germline alteration(s) that cause the syndrome. In the notes, include additional details about most common mutations including founder mutations, mechanisms of molecular pathogenesis, alteration-specific prognosis and any other important genetics-related information. If multiple causes of the syndrome, include relative prevalence of genetic contributions to that syndrome. Please include references throughout the table. Do not delete the table.'')</span> | ||
| Line 120: | Line 122: | ||
[[Category:GTS5]] | [[Category:GTS5]] | ||
[[Category:DISEASE]] | [[Category:DISEASE]] | ||
<references /> | |||