Editing Polycystic ovary syndrome (section)

=== Genetics ===
The genetic component appears to be inherited in an [[autosomal dominant]] fashion with high [[genetic penetrance]] but variable [[expressivity (genetics)|expressivity]] in females; this means that each child has a 50% chance of inheriting the predisposing genetic variant(s) from a parent, and, if a daughter receives the variant(s), the daughter will have the disease to some extent.<ref name="FertSter_molecular" /><ref name="pmid11212071" /><ref name="AnnNYAS_thoughts" /><ref name="OMIM" /> The genetic variant(s) can be inherited from either the father or the mother, and can be passed along to both sons (who may be asymptomatic carriers or may have symptoms such as early [[baldness]] and/or excessive hair) and daughters, who will show signs of PCOS.<ref name="pmid11212071">{{cite journal |vauthors=Crosignani PG, Nicolosi AE |title=Polycystic ovarian disease: heritability and heterogeneity |journal=Human Reproduction Update |volume=7 |issue=1 |pages=3–7 |date=2001 |pmid=11212071 |doi=10.1093/humupd/7.1.3 |doi-access=free }}</ref><ref name="OMIM">{{cite web |url=http://omim.org/entry/184700 |website=[[OMIM]] |title=POLYCYSTIC OVARY SYNDROME 1; PCOS1 |access-date=15 November 2011 |publisher=McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine |vauthors=Hamosh A |date=12 September 2011 |url-status=live |archive-url=https://web.archive.org/web/20150716182537/http://omim.org/entry/184700 |archive-date=16 July 2015 }}</ref> The [[phenotype]] appears to manifest itself at least partially via heightened androgen levels secreted by [[theca of follicle|ovarian follicle theca]] cells from women with the allele.<ref name="AnnNYAS_thoughts">{{cite journal | vauthors = Strauss JF | title = Some new thoughts on the pathophysiology and genetics of polycystic ovary syndrome | journal = Annals of the New York Academy of Sciences | volume = 997 | issue = 1 | pages = 42–48 | date = November 2003 | pmid = 14644808 | doi = 10.1196/annals.1290.005 | s2cid = 23559461 | bibcode = 2003NYASA.997...42S }}</ref> The exact gene affected has not yet been identified.<ref name="Endo2006" /><ref name="FertSter_molecular" /><ref name="pmid15380142">{{cite journal | vauthors = Amato P, Simpson JL | title = The genetics of polycystic ovary syndrome | journal = Best Practice & Research. Clinical Obstetrics & Gynaecology | volume = 18 | issue = 5 | pages = 707–718 | date = October 2004 | pmid = 15380142 | doi = 10.1016/j.bpobgyn.2004.05.002 }}</ref> In rare instances, single-gene mutations can give rise to the syndrome phenotype.<ref>{{cite journal | vauthors = Draper N, Walker EA, Bujalska IJ, Tomlinson JW, Chalder SM, Arlt W, Lavery GG, Bedendo O, Ray DW, Laing I, Malunowicz E, White PC, Hewison M, Mason PJ, Connell JM, Shackleton CH, Stewart PM | title = Mutations in the genes encoding 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase interact to cause cortisone reductase deficiency | journal = Nature Genetics | volume = 34 | issue = 4 | pages = 434–9 | date = August 2003 | pmid = 12858176 | doi = 10.1038/ng1214 | s2cid = 22772927 }}</ref> Current understanding of the pathogenesis of the syndrome suggests, however, that it is a complex multigenic disorder.<ref>{{cite journal | vauthors = Ehrmann DA | title = Polycystic ovary syndrome | journal = The New England Journal of Medicine | volume = 352 | issue = 12 | pages = 1223–36 | date = March 2005 | pmid = 15788499 | doi = 10.1056/NEJMra041536 | s2cid = 79796961 }}</ref>

The severity of PCOS symptoms appears to be largely determined by factors such as obesity.<ref name="Endo2006" /><ref name=BMC2010 /><ref name="pmid28416368">{{cite journal | vauthors = Faghfoori Z, Fazelian S, Shadnoush M, Goodarzi R | title = Nutritional management in women with polycystic ovary syndrome: A review study | journal = Diabetes & Metabolic Syndrome | volume = 11 | issue = Suppl 1 | pages = S429–S432 | date = November 2017 | pmid = 28416368 | doi = 10.1016/j.dsx.2017.03.030 | type = Review }}</ref> PCOS has some aspects of a [[metabolic disorder]], since its symptoms are partly reversible. Even though considered as a [[Gynaecology|gynecological]] problem, PCOS consists of 28 clinical symptoms.<ref>{{cite journal | vauthors = Witchel SF, Oberfield SE, Peña AS | title = Polycystic Ovary Syndrome: Pathophysiology, Presentation, and Treatment With Emphasis on Adolescent Girls | journal = Journal of the Endocrine Society | volume = 3 | issue = 8 | pages = 1545–73 | date = August 2019 | pmid = 31384717 | pmc = 6676075 | doi = 10.1210/js.2019-00078 }}</ref>

Even though the name suggests that the ovaries are central to disease pathology, cysts are a symptom instead of the cause of the disease. Some symptoms of PCOS will persist even if both ovaries are removed; the disease can appear even if cysts are absent. Since its first description by Stein and Leventhal in 1935, the criteria of diagnosis, symptoms, and causative factors have been subject to debate. Gynecologists often see it as a gynecological problem, with the ovaries being the primary organ affected. However, recent insights show a multisystem disorder, with the primary problem lying in hormonal regulation in the [[hypothalamus]], with the involvement of many organs. The term PCOS is used because there is a wide spectrum of symptoms possible. It is common to have polycystic ovaries without having PCOS; approximately 20% of European women <!--Do not change this word to "people". 20% of women = 10% of people because 50% of people don't have ovaries at all.--> have polycystic ovaries, but most of those women do not have PCOS.<ref name="Dunaif2013" />