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Common Tips on Communication
Published in Justin C Konje, Complete Revision Guide for MRCOG Part 3, 2020
It affects sexual development. Sexual development is usually determined by an individual’s chromosomes (with the genes on the Y chromosome being crucial in driving male sex differentiation); however, in Swyer syndrome, sexual development does not match the affected individual’s chromosomal makeup. People usually have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically have two X chromosomes (46, XX karyotype), males usually have one X chromosome and one Y chromosome (46, XY karyotype). In Swyer syndrome, individuals have one X chromosome and one Y chromosome in each cell, the pattern typically found in boys and men but have female reproductive structures. This is because the important genes that drive male sex differentiation are absent. People with Swyer syndrome have typical female external genitalia. The uterus and fallopian tubes are normally formed, but the gonads (ovaries or testes) are not functional; affected individuals have undeveloped clumps of tissue called streak gonads.
Variation of sex differentiation
Published in Joseph S. Sanfilippo, Eduardo Lara-Torre, Veronica Gomez-Lobo, Sanfilippo's Textbook of Pediatric and Adolescent GynecologySecond Edition, 2019
Anne-Marie Amies Oelschlager, Margarett Shnorhavorian
Given the complexity and variation of sex differentiation, it is not surprising that there is significant overlap in genital examination findings between different etiologies. A careful and detailed examination may provide many clues to the type of disorder as well as the timing of in utero androgen exposure. There are two standardized methods for reporting the extent of virilization or undervirilization: Prader staging (Figure 7.3) and the external masculinization score (EMS) (Table 7.4).40,41 In general, Prader staging is useful to communicate the extent of virilization of the 46,XX patient, and the EMS is useful to classify the degree of undervirilization of the 46,XY patient. The genital examination provides essential clues to the underlying etiology and includes multiple critical components.
The reproductive system
Published in Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella, Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella
Testosterone secretion may begin as early as 8 weeks after conception. Secretion reaches a peak at 12–14 weeks and then declines to very low levels by about 21 weeks. Testosterone secretion during fetal development plays a very important role in sex differentiation and the masculinizing of the embryonic structures. Secretion of testosterone begins again at puberty and is necessary for spermatogenesis, the development of secondary sex characteristics, and several anabolic effects. Secretion declines gradually and to varying degrees in males over 50 years of age. The mechanism of this decline is not known. A summary of the actions of testosterone is found in Table 12.1.
The use of in silico extreme pathway (ExPa) analysis to identify conserved reproductive transcriptional-regulatory networks in humans, mice, and zebrafish
Published in Systems Biology in Reproductive Medicine, 2023
Reproductive TRNs have been systematically discovered and assembled using animal models or the study of human DSD (Jost 1979; Veitia et al. 1997; Eggers and Sinclair 2012; Ono and Harley 2013; Nagahama et al. 2021). This cumulative effort has revealed that while the genetic regulation of sex determination is highly varied across animal taxa (Trukhina et al. 2013; Stöck et al. 2021), the genes and transcription factors (TFs) responsible for coordinating sex differentiation and maintaining reproductive functions are overall well-conserved (Cutting et al. 2013; Herpin and Schartl 2015; Capel 2017). Relatively recently, high-throughput comparative genomics, transcriptomics, and in silico (computational biology or bioinformatics) approaches have also been used to identify the design principles of reproductive TRNs and to characterize their altered functions in disease pathologies (Eggers and Sinclair 2012; Eggers et al. 2016; Nagaraja et al. 2019; Estermann and Smith 2020; Ye and Chen 2020).
Total testosterone level may have no influence on the occurrence and severity of erectile dysfunction in males aged between 30 and 60 years living with type 2 diabetes
Published in Journal of Endocrinology, Metabolism and Diabetes of South Africa, 2022
Martine Claude Etoa Etoga, Doris Bibi Essama, Achille Aurèle Mbassi, Jan René Nkeck, Francine Mendane Mekobe, Mesmin Dehayem, Ama Moor Vicky, Eugène Sobngwi, Jean Claude Mbanya
The present study assessed the contribution of testosterone in erectile dysfunction in patients living with T2DM. Testosterone is the main androgen in male responsible for sex differentiation of external genitals. It is also useful in the triggering and maintenance of erectile function. ED in T2DM is generally a consequence of the low level of NO resulting in an endothelial dysfunction in the intracavernous tissues. Efficient treatment of ED could improve patients’ quality of life. A low testosterone level could be apparent as a remediable cause of ED and for this reason it should be assessed. We measured total testosterone using the immuno-assay method. Although liquid chromatography coupled with mass spectrometry (LC-MS/MS) is the method recommended by the Endocrine Society for determination of androgens, it is more expensive and labour-intensive so that it cannot be easily applicable for cohort studies. Some authors recommend immunoassay in routine assessment of total testosterone. This method is equal and has a sensibility comparable to LC-MS/MS.15
Molecular study and genotype–phenotype in Chinese female patients with 46, XY disorders of sex development
Published in Gynecological Endocrinology, 2021
Junke Xia, Jing Wu, Chen Chen, Zhenhua Zhao, Yanchuan Xie, Zhouxian Bai, Xiangdong Kong
Androgens are key elements of male sex differentiation. After normal testicle development, leydig cells produce testosterone, which promotes genital virilization [22]. Mutations in the AR gene (OMIM #313700) result in a loss-of-function androgen, leading to androgen insensitivity syndrome (AIS), which is the most common cause of 46, XY DSDs. The phenotype ranges from normal female external genitalia in the complete form (CAIS) to normal male external genitalia associated with infertility and/or gynecomastia in the mild form (MAIS) [23,24]. Here, a novel missense variant (Cys580Ser) was identified in a highly conserved residue of the DBD, which contains two zinc finger configurations [24]. Four cysteine residues coordinately bind to a zinc ion in each of the two zinc fingers. Hence, we hypothesized that cysteine change affected the three-dimensional structure of the first zinc finger and led to loss of DBD activity.