Epigenetic Regulation and Environmental Sex Determination in Cichlid Fishes
Studying environmental sex determination (ESD) in cichlids provides a phylogenetic and comparative approach to understand the evolution of the underlying mechanisms, their impact on the evolution of the overlying systems, and the neuroethology of life history strategies. Natural selection normally favors parents who invest equally in the development of male and female offspring, but evolution may favor deviations from this 50:50 ratio when environmental conditions produce an advantage for doing so. Many species of cichlids demonstrate ESD in response to water chemistry (temperature, pH, and oxygen concentration). The relat...
Source: Sexual Development - August 25, 2021 Category: Biology Source Type: research
WT1 Pathogenic Variants are Associated with a Broad Spectrum of Differences in Sex Development Phenotypes and Heterogeneous Progression of Renal Disease
In this report, we describe the phenotypes and genotypes of 7 Brazilian patients with pathogenicWT1 variants. The molecular study involved Sanger sequencing and massively parallel targeted sequencing using a DSD-associated gene panel. Six patients (5 with a 46,XY karyotype and 1 with a 46,XX karyotype) were initially evaluated for atypical genitalia, and a 46,XY patient with normal female genitalia sought medical attention for primary amenorrhea. Germ cell tumors were identified in 2 patients, both with variants affecting alternative splicing ofWT1 between exons 9 and 10. Two pathogenic missenseWT1 variants were identified...
Source: Sexual Development - August 13, 2021 Category: Biology Source Type: research
Can Boys Have Turner Syndrome? More than a Question of Semantics
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 ...
Source: Sexual Development - August 10, 2021 Category: Biology Source Type: research
A Nationwide Study of the Prevalence and Initial Management of Atypical Genitalia in the Newborn in Scotland
This study provides new clinical benchmarks for comparing and improving the delivery of care in centres that manage these conditions.Sex Dev (Source: Sexual Development)
Source: Sexual Development - August 5, 2021 Category: Biology Source Type: research
Erratum
Sex Dev (Source: Sexual Development)
Source: Sexual Development - July 30, 2021 Category: Biology Source Type: research
Clinical, Hormonal, Genetic, and Molecular Characteristics in Androgen Insensitivity Syndrome in an Asian Indian Cohort from a Single Centre in Western India
The study aimed to analyze clinical and hormonal phenotype,and genotype in patients with genetically proven androgen insensitivity syndrome (AIS) from Western India. Index patients with pathogenic variants in the androgen receptor (AR) gene were identified from a consecutive 46,XY DSD cohort (n = 150) evaluated with clinical exome sequencing, and their genetically-proven affected relatives were also included. In sum, 15 index cases (9 complete AIS [CAIS] and 6 partial AIS [PAIS]) were identified making AIS the second most common (10%) cause of 46,XY DSD, next to 5 α-reductase 2 deficiency (n = 26; 17.3%). Most patients pr...
Source: Sexual Development - July 30, 2021 Category: Biology Source Type: research
Concerning an Article by Ehl et al.: False Premise Leads to False Conclusions
Sex Dev (Source: Sexual Development)
Source: Sexual Development - July 29, 2021 Category: Biology Source Type: research
Expanding DSD Phenotypes Associated with Variants in the DEAH-Box RNA Helicase DHX37
Missense variants in the RNA-helicase DHX37 are associated with either 46,XY gonadal dysgenesis or 46,XY testicular regression syndrome (TRS). DHX37 is required for ribosome biogenesis, and this subgroup of XY DSD is a new human ribosomopathy. In a cohort of 140 individuals with 46,XY DSD, we identified 7 children with either 46,XY complete gonadal dysgenesis or 46,XY TRS carrying rare or novel DHX37 variants. A novel p.R390H variant within the RecA1 domain was identified in a girl with complete gonadal dysgenesis. A paternally inherited p.R487H variant, previously associated with a recessive congenital developmental syndr...
Source: Sexual Development - July 22, 2021 Category: Biology Source Type: research
Surgical Practice in Girls with Congenital Adrenal Hyperplasia: An International Registry Study
In this article international trends in surgical practice in girls with congenital adrenal hyperplasia (CAH) are evaluated. All cases that had been classified in the I-CAH/I-DSD registry as 46,XX CAH and who were born prior to 2017 were identified. Centers were approached to obtain information on surgical decision making. Of the 330 included participants, 208 (63.0%) presented within the first month of life, and 326 (98.8%) cases were assigned female. Genital surgery had been performed in 250 (75.8%). A total of 64.3, 89.2, and 96.8% of cases residing in Europe, South America and Asia, respectively, had at least one surger...
Source: Sexual Development - July 21, 2021 Category: Biology Source Type: research
Metabolism and Sex Differentiation in Animals from a Starvation Perspective
Animals determine their sex genetically (GSD: genetic sex determination) and/or environmentally (ESD: environmental sex determination). Medaka (Oryzias latipes) employ a XX/XY GSD system, however, they display female-to-male sex reversal in response to various environmental changes such as temperature, hypoxia, and green light. Interestingly, we found that 5 days of starvation during sex differentiation caused female-to-male sex reversal. In this situation, the metabolism of pantothenate and fatty acid synthesis plays an important role in sex reversal. Metabolism is associated with other biological factors such as germ cel...
Source: Sexual Development - July 20, 2021 Category: Biology Source Type: research
Evolutionary Turnover in Wnt Gene Expression but Conservation of Wnt Signaling during Ovary Determination in a TSD Reptile
Temperature-dependent sex determination (TSD) is a well-known characteristic of many reptilian species. However, the molecular processes linking ambient temperature to determination of gonad fate remain hazy. Here, we test the hypothesis that Wnt expression and signaling differ between female- and male-producing temperatures in the snapping turtleChelydra serpentina. Canonical Wnt signaling involves secretion of glycoproteins called WNTs, which bind to and activate membrane bound receptors that trigger β-catenin stabilization and translocation to the nucleus where β-catenin interacts with TCF/LEF transcription factors to...
Source: Sexual Development - July 19, 2021 Category: Biology Source Type: research
Preface to the Special Issue on Sexual Development and the Environment
Sex Dev (Source: Sexual Development)
Source: Sexual Development - July 14, 2021 Category: Biology Source Type: research
Testosterone Therapy and Its Monitoring in Adolescent Boys with Hypogonadism: Results of an International Survey from the I-DSD Registry
It is unclear whether testosterone replacement therapy (TRT) in adolescent boys, affected by a range of endocrine diseases that may be associated with hypogonadism, is particularly common. The aim of this study was to assess the contemporary practice of TRT in boys included in the I-DSD Registry. All participating centres in the I-DSD Registry that had boys between 10 and 18 years of age and with a condition that could be associated with hypogonadism were invited to provide further information in 2019. Information on 162 boys was collected from 15 centres that had a median (range) number of 6 boys per centre (1.35). Of the...
Source: Sexual Development - July 7, 2021 Category: Biology Source Type: research
Might Gene Duplication and Neofunctionalization Contribute to the Sexual Lability Observed in Fish?
Sex determination and differentiation varies widely across vertebrates, but is most dramatically diverse in fishes. Among fishes sex reversal and sex change are observed in 41 teleost families spanning 7 orders. These sex-changing fish perhaps highlight better than any other system that sex determination is not the narrow and fixed construct we once thought, but a plastic trait that is better viewed as a reaction norm. However, while this stunning transformation is increasingly understood, a fundamental question arises, which is why some fish species have retained this inherent plasticity in sexual fate, while others have ...
Source: Sexual Development - June 24, 2021 Category: Biology Source Type: research
Molecular and Cellular Mechanisms Underlying Temperature-Dependent Sex Determination in Turtles
The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment ’s role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief rev...
Source: Sexual Development - June 24, 2021 Category: Biology Source Type: research
