Sexual Development最新文献

Introduction: Ovotesticular disorder of sex development (OT-DSD) is a rare condition defined by concomitance of testicular tissue and ovarian tissue (containing follicles) in the same individual. In SRY-negative 46,XX OT-DSD, the presence of testicular tissue may be due to variations in NR5A1. Our aims were to search for NR5A1 variants in SRY-negative 46,XX OT-DSD patients and to perform a systematic review on the contribution of NR5A1 variations to 46,XX OT-DSD.

Methods: Sanger sequencing of NR5A1 was performed in seven SRY-negative 46,XX OT-DSD patients: five simplex cases and two with another sibling with a 46,XX DSD. Systematic review of original studies on NR5A1 sequencing of 46,XX OT-DSD patients was performed according to PRISMA-P guideline. Case reports were selected for analysis of clinical features. Individuals with NR5A1-associated testicular DSD were not included.

Results: Sanger sequencing of NR5A1 did not reveal pathogenic variants among our patients. Our cohort was included in this systematic review with seven other articles, totalizing fifty-six 46,XX OT-DSD patients investigated by Sanger or whole-exome sequencing. From them, three NR5A1 pathogenic variants were identified (5% of the cases). Clinical analysis of these 3 cases and 5 case reports revealed: predominance of ovotestis (13/16 gonads) and bilateral OT-DSD (5/8 cases).

Conclusion: The etiology of most 46,XX OT-DSD cases remains elusive, highlighting the importance of a deeper molecular investigation.

Background: The germ cell lineage involves dynamic epigenetic changes during its formation and differentiation that are completely different from those of the somatic cell lineage. Metabolites and metabolic pathways have been reported as key factors related to the regulation of epigenetics as cofactors and substrates. However, our knowledge about the metabolic characteristics of germ cells, especially during the fetal stage, and their transition during differentiation is quite limited due to the rarity of the cells. Nevertheless, recent developments in omics technologies have made it possible to extract comprehensive metabolomic features of germ cells.

Summary: In this review, we present the latest researches on the metabolic properties of germ cells in 4 stages: primordial germ cell specification, fetal germ cell differentiation, spermatogenesis, and oogenesis. At every stage, extensive published data has been accumulated on energy metabolism, and it is possible to describe its changes during germ cell differentiation in detail. As pluripotent stem cells differentiate into germ cells, energy metabolism shifts from glycolysis to oxidative phosphorylation; however, in spermatogenesis, glycolytic pathways are also temporarily dominant in spermatogonial stem cells. Although the significance of metabolic pathways other than energy metabolism in germ cell differentiation is largely unknown, the relation of the pentose phosphate pathway and Ser-Gly-one-carbon metabolism with germ cell properties has been suggested at various stages. We further discuss the relationship between these characteristic metabolic pathways and epigenetic regulation during germ cell specification and differentiation. Finally, the relevance of dietary and supplemental interventions on germ cell function and epigenomic regulation is also discussed.

Key messages: Comprehensive elucidation of metabolic features and metabolism-epigenome crosstalk in germ cells is important to reveal how the characteristic metabolic pathways are involved in the germ cell regulation. The accumulation of such insights would lead to suggestions for optimal diets and supplements to maintain reproductive health through modulating metabolic and epigenetic status of germ cells.

Introduction: Disorders of gonadal development represent a clinically and genetically heterogeneous group of DSD, and the etiology in many cases remains unknown, indicating that our knowledge of factors controlling sex determination is still limited.

Methods: We describe a 46,XY DSD patient from Egypt. The patient was reared as female, born to consanguineous parents, and was referred to us at the age of 5 years because of ambiguous genitalia. On examination, the girl was microcephalic (head circumference -3 SD), but her height and weight were normal for her age and sex.

Results: Exome sequencing identified a homozygous variant in the hedgehog acyltransferase (HHAT) gene, which encodes an enzyme that is required for multimerization and signaling potency of the hedgehog secreted proteins. The variant is a novel homozygous missense change c.1329C>A (p.N443K), located within transmembrane domain 9, which segregated with the phenotype in the family.

Discussion/conclusion: Our results expand the phenotypic spectrum associated with HHAT variants to include 46,XY gonadal dysgenesis and reinforce the role of exome sequencing in unraveling new genes that play a pivotal role in sexual development.

Introduction: People with differences of sex development (DSD) and their families need education about these conditions while receiving emotional and peer support to participate in shared decision-making, reduce social isolation, and optimize physical and psychosocial outcomes. Barriers to education and support include limited knowledge and awareness by healthcare providers, tension among patient and medical communities, varied quality of educational resources, and the sensitive nature of DSD. We aimed to create an electronic repository of vetted quality online resources about DSD.

Methods: The electronic resource repository (e-RR) was a collaboration between affected individuals and advocates and healthcare providers in the DSD-Translational Research Network (DSD-TRN), an NIH-supported consortium of US teams committed to standardizing and optimizing care in DSD. The e-RR development and ongoing growth involved: (1) identification of resources by the project team (3 advocates and 1 physician), (2) evaluation and feedback by DSD-TRN clinical teams, (3) creation of the e-RR, and (4) review and revision. Twitter-like descriptions accompanied each entry; resources were categorized by target age, audience, and condition.

Results: Thirty-seven web-based educational, peer and advocacy support, and clinician-oriented resources were reviewed. Eight of 10 DSD-TRN teams responded to a survey regarding resource inclusion. Awareness of individual resources varied widely. Consensus was achieved when opinions differed; 30 resources were included. The e-RR is available online and as a downloadable booklet at http://www.accordalliance.org/resource-guide/.

Conclusion: The e-RR increases awareness of and access to vetted educational and support resources for those with DSD and healthcare providers. It represents important collaboration between advocates and providers.

Individuals with 45,X mosaicism with Y chromosome material raised as boys are not diagnosed with Turner syndrome, a label restricted to phenotypic females. We sought to determine if boys with 45,X mosaicism had features consistent with Turner syndrome. Twenty-two patients (14 girls, 8 boys) seen in our Differences of Sex Development (DSD) clinic were identified for review. Standardized height (z-scores) by sex of rearing and results of cardiology, renal, audiology, thyroid, and celiac screenings were recorded. All subjects had heights below the mean for sex. Z-scores were not significantly different between boys and girls (p = 0.185). There were no significant differences in the incidence of cardiac anomalies between boys and girls (p = 0.08). Girls were more likely to have additional screenings (p = 0.042), but there were no significant differences in the number of positive screenings between boys and girls (p = 0.332). Patients with 45,X mosaicism raised as boys appear to have features similar to patients with the same karyotype raised as girls. Routine screening of boys following the Turner Syndrome Clinical Practice Guidelines may allow early recognition of comorbidities. Additionally, obtaining karyotypes on boys with short stature or other features of Turner syndrome may identify unrecognized cases of 45,X mosaicism.

Introduction: Hermaphroditism is a mode of reproduction involving an individual animal that possesses both a testis and an ovary either sequentially or simultaneously. The mechanism creating hermaphrodites remains unknown. Previously, we identified foxl3 as the germline sex determination gene in a gonochoristic fish, medaka (Oryzias latipes). foxl3 loss-of-function (foxl3-/-) females produce functional sperm as well as eggs in the ovary. However, these two gametes are not self-fertilizing because of the histological separation of each gamete production. In this study, we attempted to generate self-fertilizing medaka from female medaka by modifying germline sex using foxl3-/- mutants and by using exogenous androgen to induce partial sex reversal of somatic cells.

Methods: foxl3-/- XX females were treated with 11-ketotestosterone (11-KT), a potent teleost fish androgen, at the sexually mature stage for 30 days (90-120 dph). Then, the fish were kept under normal conditions until they were either being dissected or crossed with infertile males.

Results and discussion: We showed that the foxl3-/- XX female medaka can be transformed into a self-fertilizing hermaphrodite by inducing the formation of a male-like structure with exogenous 11-KT. Self-fertilization occurs in either the ovarian cavity, the oviduct, or both where sperm is released from a tubule-like structure which is likely derived from germinal epithelium, suggesting that timely modification of 2 independent mechanisms, regulation of germline sex and partial sex reversal of somatic cells, are critical to change the reproduction mode. Our results will provide insights in developmental and evolutional occurrence of hermaphrodite vertebrates, facilitate an innovative technique to improve the efficient selection of fish with desirable traits, and contribute to the rescue of endangered species.

Deficiency of 3β-hydroxysteroid dehydrogenase type 2 (3βHSD2) is a rare type of congenital adrenal hyperplasia (CAH), causing impaired steroid hormone production in both adrenals and gonads. Phenotype ranges, according to the genetic defect, from the salt-wasting form in both sexes to undervirilization in males and virilization in females. We present a 13-month-old male infant who was admitted to the hospital with signs of adrenocortical insufficiency and genital ambiguity. Clinical presentation, hormonal profile, laboratory evaluation, and karyotype were suggestive of the salt-wasting form of CAH due to 3βHSD2 deficiency. Mutational analysis revealed a missense mutation c.776C>T (p.Thr259Met), inherited by the mother, and a frameshift deletion c.818-819delAA (p.Lys273ArgFs*7), inherited by the father. Both mutations are considered pathogenic. To our knowledge this is the first case of an undervirilized male infant with salt wasting bearing this pathogenic frameshift deletion p.Lys273ArgFs*7 in compound heterozygosity with the missense mutation p.Thr259Met.

Background: Germ cells are critical for the survival of our species. They are the only cells that undergo meiosis - the reductive form of cell division that is necessary for genetic reassortment of chromosomes and production of the haploid gametes, the sperm and eggs. Remarkably, the initial female/male fate decision in fetal germ cells does not depend on whether they are chromosomally XX or XY; rather, initial sexual fate is imposed by influences from the surrounding tissue. In mammals, the female germline is particularly precious: despite recent suggestions that germline stem cells exist in the ovary, it is still generally accepted that the ovarian reserve is finite, and its size is dependant on germ cells of the fetal ovary initiating meiosis in a timely manner.

Summary: Prior to 2006, evidence suggested that gonadal germ cells initiate meiotic prophase I by default, but more recent data support a key role for the signalling molecule retinoic acid (RA) in instructing female germ cell fate. Newer findings also support a key meiosis-inducing role for another signalling molecule, bone morphogenic protein (BMP). Nonetheless, many questions remain.

Key messages: Here, we review knowledge thus far regarding extrinsic and intrinsic determinants of a female germ cell fate, focusing on the mouse model.