{"title":"Systematization of ambiguous genitalia.","authors":"Zograb Makiyan","doi":"10.1080/15476278.2016.1210749","DOIUrl":null,"url":null,"abstract":"<p><p>Sex assignment in newborns depends on the anatomy of the external genitalia, despite this stage being the final in embryogenesis. According to the current view, the genital tubercle is the embryonic precursor of penis and clitoris. It originates from mesenchymal tissue, but mesenchymal cells are arranged across the embryonal body and do not have specific androgen receptors. The nature of the signal that initiates early derivation of the indifferent genital tubercle is unknown at present. The aims of this article are to improve surgical management of intersex disorders and investigate the development of the genital tubercle. Clinical examination of 114 females with various forms of DSD revealed ambiguous (bisexual) external genitalia in 73 patients, and 51 of them underwent feminizing surgery. Intersexuality (ambiguity) in 46,XY patients results from disruptors in the pathways of sex steroid hormones or receptors; in 46,XX females arises from excessive levels of androgens. Systematization of intersex disorders distinguishes the karyotype, gonadal morphology, and genital anatomy to provide a differential diagnosis and guide appropriate surgical management. Modified feminizing clitoroplasty with preservation of the dorsal and ventral neurovascular bundles to retain erogenous sensitivity was performed in females with severe virilization (Prader degree III-V). The outgrowth of the genital tubercle and the fusion of the urethral fold proceed in an ordered fashion; but in some cases of ambiguity, there was discordance due to different pathways. Speculation about the derivation of the genital tubercle have discussed with a literature review. The genital tubercle derives from the following 3 layers: the ectodermal glans of the tubercle, the mesodermal corpora cavernosa and the endodermal urogenital groove. According to the new hypothesis, during the indifferent stages, the 5 sacral somites have to recede from their segmentation and disintegrate: the sclerotomes form the pelvic bones, the fused myotomes follow with their genuine neurotomes and the angiotomes join to the corpora cavernosa of the genital tubercle. Sexual differentiation of external genitalia is final in gender embryogenesis, but surprisingly derivation of the indifferent genital tubercle from 5 somites occurs before gonadal and internal organs development.</p>","PeriodicalId":19596,"journal":{"name":"Organogenesis","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15476278.2016.1210749","citationCount":"13","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organogenesis","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1080/15476278.2016.1210749","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2016/7/8 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 13
Abstract
Sex assignment in newborns depends on the anatomy of the external genitalia, despite this stage being the final in embryogenesis. According to the current view, the genital tubercle is the embryonic precursor of penis and clitoris. It originates from mesenchymal tissue, but mesenchymal cells are arranged across the embryonal body and do not have specific androgen receptors. The nature of the signal that initiates early derivation of the indifferent genital tubercle is unknown at present. The aims of this article are to improve surgical management of intersex disorders and investigate the development of the genital tubercle. Clinical examination of 114 females with various forms of DSD revealed ambiguous (bisexual) external genitalia in 73 patients, and 51 of them underwent feminizing surgery. Intersexuality (ambiguity) in 46,XY patients results from disruptors in the pathways of sex steroid hormones or receptors; in 46,XX females arises from excessive levels of androgens. Systematization of intersex disorders distinguishes the karyotype, gonadal morphology, and genital anatomy to provide a differential diagnosis and guide appropriate surgical management. Modified feminizing clitoroplasty with preservation of the dorsal and ventral neurovascular bundles to retain erogenous sensitivity was performed in females with severe virilization (Prader degree III-V). The outgrowth of the genital tubercle and the fusion of the urethral fold proceed in an ordered fashion; but in some cases of ambiguity, there was discordance due to different pathways. Speculation about the derivation of the genital tubercle have discussed with a literature review. The genital tubercle derives from the following 3 layers: the ectodermal glans of the tubercle, the mesodermal corpora cavernosa and the endodermal urogenital groove. According to the new hypothesis, during the indifferent stages, the 5 sacral somites have to recede from their segmentation and disintegrate: the sclerotomes form the pelvic bones, the fused myotomes follow with their genuine neurotomes and the angiotomes join to the corpora cavernosa of the genital tubercle. Sexual differentiation of external genitalia is final in gender embryogenesis, but surprisingly derivation of the indifferent genital tubercle from 5 somites occurs before gonadal and internal organs development.
期刊介绍:
Organogenesis is a peer-reviewed journal, available in print and online, that publishes significant advances on all aspects of organ development. The journal covers organogenesis in all multi-cellular organisms and also includes research into tissue engineering, artificial organs and organ substitutes.
The overriding criteria for publication in Organogenesis are originality, scientific merit and general interest. The audience of the journal consists primarily of researchers and advanced students of anatomy, developmental biology and tissue engineering.
The emphasis of the journal is on experimental papers (full-length and brief communications), but it will also publish reviews, hypotheses and commentaries. The Editors encourage the submission of addenda, which are essentially auto-commentaries on significant research recently published elsewhere with additional insights, new interpretations or speculations on a relevant topic. If you have interesting data or an original hypothesis about organ development or artificial organs, please send a pre-submission inquiry to the Editor-in-Chief. You will normally receive a reply within days. All manuscripts will be subjected to peer review, and accepted manuscripts will be posted to the electronic site of the journal immediately and will appear in print at the earliest opportunity thereafter.