A novel DEAH-box helicase 37 mutation associated with differences of sex development.

Objective: To determine the genetic etiology of a family pedigree with two patients affected by differences of sex development (DSD). Methods: Assess the clinical characteristics of the patients and achieve exome sequencing results and in vitro functional studies. Results: The 15-year-old proband, raised as female, presented with delayed puberty and short stature associated with atypical genitalia. Hormonal profile showed hypergonadotrophic hypogonadism. Imaging studies revealed the absence of a uterus and ovaries. The karyotype confirmed a 46, XY pattern. Her younger brother presented with a micropenis and hypoplastic scrotum with non-palpable testis and hypospadias. Laparoscopic exploration was performed on the younger brother. Streak gonads were found and removed due to the risk of neoplastic transformation. Post-operative histopathology showed the co-existence of Wolffian and Müllerian derivatives. Whole-exome sequencing identified a novel mutation (c.1223C>T, p. Ser408Leu) in the Asp-Glu-Ala-His-box helicase 37 gene, which was found to be deleterious by in silico analysis. Segregation analysis of the variant displayed a sex-limited, autosomal dominant, maternal inheritance pattern. In vitro experiments revealed that the substitution of 408Ser by Leu caused decreased DHX37 expression both at the mRNA and protein levels. Moreover, the ß-catenin protein was upregulated, and the p53 protein was unaltered by mutant DHX37. Conclusions: We described a novel mutation (c.1223C>T, p. Ser408Leu) of the DHX37 gene associated with a Chinese pedigree consisting of two 46, XY DSD patients. We speculated that the underlying molecular mechanism might involve upregulation of the ß-catenin protein.

Non-obvious diagnosis and breast development in pure gonadal dysgenesis.

Pure gonadal dysgenesis is a situation when the karyotype is 46, XY, but for various reasons there is a disorder of differentiation of Wolffian and Mullerian structures and in consequence the phenotype is female. It is known that abdominal gonads and the presence of Y chromosome allow to qualify this condition as a high risk of tumor. In most cases breast development is limited because of lack or low level of estrogen. A 27-year-old patient with differences of sexual development (DSD), was admitted to the Department of Endocrinological Gynecology for a control examination. In the history: dysgerminoma, primary amenorrhea and ambiguous karyotype. The patient has not taken hormonal replacement therapy. The breast development is Tanner stage V.

Developmental exposure to real-life environmental chemical mixture programs a testicular dysgenesis syndrome-like phenotype in prepubertal lambs.

Current declines in male reproductive health may, in part, be driven by anthropogenic environmental chemical (EC) exposure. Using a biosolids treated pasture (BTP) sheep model, this study examined the effects of gestational exposure to a translationally relevant EC mixture. Testes of 8-week-old ram lambs from mothers exposed to BTP during pregnancy contained fewer germ cells and had a greater proportion of Sertoli-cell-only seminiferous tubules. This concurs with previous published data from fetuses and neonatal lambs from mothers exposed to BTP. Comparison between the testicular transcriptome of biosolids lambs and human testicular dysgenesis syndrome (TDS) patients indicated common changes in genes involved in apoptotic and mTOR signalling. Gene expression data and immunohistochemistry indicated increased HIF1α activation and nuclear localisation in Leydig cells of BTP exposed animals. As HIF1α is reported to disrupt testosterone synthesis, these results provide a potential mechanism for the pathogenesis of this testicular phenotype, and TDS in humans.

Endocrine Disrupting Chemicals and Reproductive Health in Boys and Men.

Male reproductive health has declined as indicated by increasing rates of cryptorchidism, i.e., undescended testis, poor semen quality, low serum testosterone level, and testicular cancer. Exposure to endocrine disrupting chemicals (EDCs) has been proposed to have a role in this finding. In utero exposure to antiandrogenic EDCs, particularly at a sensitive period of fetal testicular development, the so-called 'masculinization programming window (MPW)', can disturb testicular development and function. Low androgen effect during the MPW can cause both short- and long-term reproductive disorders. A concurrent exposure to EDCs may also affect testicular function or damage testicular cells. Evidence from animal studies supports the role of endocrine disrupting chemicals in development of male reproductive disorders. However, evidence from epidemiological studies is relatively mixed. In this article, we review the current literature that evaluated relationship between prenatal EDC exposures and anogenital distance, cryptorchidism, and congenital penile abnormality called hypospadias. We review also studies on the association between early life and postnatal EDC exposure and semen quality, hypothalamic-pituitary-gonadal axis hormone levels and testicular cancer.

Revisiting the hybridization processes in the Triatoma brasiliensis complex (Hemiptera, Triatominae): Interspecific genomic compatibility point to a possible recent diversification of the species grouped in this monophyletic complex.

Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b. brasiliensis, T. b. macromelasoma, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae and T. sherlocki. The specific status of several species grouped in the T. brasiliensis complex was confirmed from experimental crossing and analysis of reproductive barriers. Thus, we perform interspecific experimental crosses between T. lenti and other species and subspecies of the T. brasiliensis complex and perform morphological analysis of the gonads and cytogenetic analysis in the homeologous chromosomes of the hybrids of first generation (F1). Besides that, we rescue all the literature data associated with the study of reproductive barriers in this monophyletic complex of species and subspecies. For all crosses performed between T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis and T. melanica with T. lenti, interspecific copulas occurred (showing absence of mechanical isolation), hybrids were obtained, none of the male hybrids presented the phenomenon of gonadal dysgenesis and 100% pairing between the chromosomes homeologous of the hybrids was observed. Thus, we demonstrate that there are no pre-zygotic reproductive barriers installed between T. lenti and the species and subspecies of the T. brasiliensis complex. In addition, we demonstrate that the hybrids obtained between these crosses have high genomic compatibility and the absence of gonadal dysgenesis. These results point to reproductive compatibility between T. lenti and species and subspecies of the T. brasiliensis complex (confirming its inclusion in the complex) and lead us to suggest a possible recent diversification of the taxa of this monophyletic group.

Phthalate Toxicity in Rats and Its Relation to Testicular Dysgenesis Syndrome in Humans.

This work describes the relevance of toxicology studies of environmental chemicals, with a focus on phthalates, for a hypothesis that certain human male reproductive disorders and diseases have a common etiology of disturbance of normal development in utero. The "Testicular Dysgenesis Syndrome" hypothesis in humans has parallels in male reproductive tract abnormalities and microscopic lesions reported for phthalate toxicity in rats. Additionally, this work describes the histological findings of abnormal testicular development (testicular dysgenesis) in rats as compared to those in humans, as well as potential findings in rats at different ages, from the embryo to the adult.

Reconstitution of rat fetal testis during the masculinisation programming window induces focal dysgenesis consistent with testicular dysgenesis syndrome.

Focal dysgenesis is a consistent feature of testicular dysgenesis syndrome (TDS) in humans. Rodent studies show that perturbation of androgens (e.g. following phthalate exposure) during a fetal masculinisation programming window (MPW) predisposes to a TDS phenotype. This study aimed to determine whether dissociation and reconstitution of rat fetal testis tissue during the MPW can be used to model and manipulate seminiferous cord development, including induction of focal dysgenesis, as described in TDS. Dissociated fetal rat testes were xenotransplanted subcutaneously into recipient mice for 4 weeks. Transplanted mice were treated with vehicle or di-n-butyl-phthalate (DBP, a plasticising chemical known to induce testicular dysgenesis in vivo in rats). Testosterone production by the transplants was measured in recipient mice and immunofluorescence was performed on the retrieved transplants to identify features consistent with focal testicular dysgenesis. Re-aggregation of rat fetal testis tissue xenotransplants during the MPW results in reconstitution of seminiferous cords. Features of focal testicular dysgenesis were present in re-aggregated testis, including ectopic Sertoli cells and intratubular Leydig cells (ITLCs). DBP exposure of recipient mice reduced androgen-dependent seminal vesicle weight (8.3 vs 26.7 mg; p < 0.05), but did not enhance features of focal dysgenesis including number of ITLCs (0.07 vs 0.10 cells/mm2; p > 0.05). We conclude that seminiferous cord reformation during the MPW results in development of focal dysgenesis. The system may be used to separate specific effects (e.g. androgen suppression) of individual chemical exposures from other mechanisms that may be conserved in TDS.

The Potential Synergic Effect of a Complex Pattern of Multiple Inherited Genetic Variants as a Pathogenic Factor for Ovarian Dysgenesis: A Case Report.

Non-syndromic primary ovarian insufficiency due to ovarian dysgenesis in 46,XX patients is an uncommon finding in the general population, even though several monogenic variants have been reported as causative factors. Here, we describe a 15-year-old patient diagnosed with gonadal dysgenesis possibly due to the interaction of three potentially pathogenic variants of genes involved in ovarian maturation, namely factor in the germline alpha (FIGLA), newborn ovary homeobox-encoding (NOBOX) and nuclear receptor subfamily 5 group A member 1 (NR5A1). We also describe a different degree of residual ovarian function within the proband's family, whose female members carry one to three demonstrated variations in the aforementioned genes in a clinical spectrum potentially dependent on the number of alleles involved. Our results support the hypothesis that the severity of the clinical picture of the proband, resulting in complete ovarian dysgenesis, may be due to a synergic detrimental effect of inherited genetic variants.

Features of gonadal dysgenesis and Leydig cell impairment in testes with Sertoli cell-only syndrome.

INTRODUCTION: There is evidence that disturbed spermatogenesis is associated with impaired Leydig cell function and that it may be the result of testicular dysgenesis during fetal/infant development. Sertoli cell-only syndrome (SCOS) is defined by complete lack of germ cells in the seminiferous epithelium. The pathogenesis of SCOS is still not well understood. The aim of the study is to evaluate testes with SCOS focusing on morphometric signs of testicular dysgenesis and markers of Leydig cell (LC) function in relation to hormonal status of studied infertile men. MATERIALS AND METHODS: Forty-nine testicular biopsies of patients with SCOS and 15 controls with normal spermatogenesis (NOR) were studied. In each biopsy the seminiferous tubule diameter (STD), thickness of tubular membrane (TM), area fraction of intertubular space (AFIS) were measured and semi-quantitative assessment of the LC number was performed (LC-score). The results of histological examination were correlated with serum levels of FSH, LH, testosterone (T) and T/LH ratio. RESULTS: In SCOS group testicular volume (median [M]: 16.0 vs. 29.5; p < 0.001) and STD (M: 141.7 vs. 190.2; p < 0.001) were lower, while TM (M: 9.8 vs. 6.4; p < 0.001) and AFIS (M: 47.6 vs. 27.6; p < 0.001) were significantly higher in comparison to NOR group. LC-score was higher in SCOS than in NOR group (M: 2.2 vs. 1.1; p < 0.001). Abnormal AFIS and STD were present in 43% of SCOS biopsies and among them in 81% the increased LC-score was found. In SCOS group, the subjects had significantly higher levels of both gonadotropins (FSH, M: 19.9 vs. 3.4; p < 0.001; LH, M: 7.1 vs. 4.2; p < 0.001). Total serum testosterone level did not differ between studied groups; however, T/LH ratio was significantly lower in SCOS group (M: 2.3 vs. 3.8; p < 0.001). Negative correlation between LC-score and STD was observed in SCOS group (r = -0.48; p < 0.001). AFIS correlated positively with serum FSH level in NOR (r = 0.53; p < 0.05) and SCOS (r = 0.41; p < 0.05) group, while with LH, and negatively with T/LH ratio, only in SCOS (LH, r = 0.37; p < 0.05; T/LH, r = -0.36; p < 0.05) group. CONCLUSIONS: We have shown that substantial number of testes from subjects with SCOS presented abnormal morphometric features, which are recognized as the signs of testicular dysgenesis. Additionally, an increased number of Leydig cells simultaneously with abnormal T/LH ratio were found, which suggests an impaired function of these cells. Increased serum levels of LH and also FSH, may reflect dysfunction of Leydig cells. It seems that reproductive hormones levels reflect also the condition of testicular structure, and that FSH may be related to the changes in intertubular space area independently of impaired Leydig cell function.

The gene encoding the ketogenic enzyme HMGCS2 displays a unique expression during gonad development in mice.

Disorders/differences of sex development (DSD) cause profound psychological and reproductive consequences for the affected individuals, however, most are still unexplained at the molecular level. Here, we present a novel gene, 3-hydroxy-3-methylglutaryl coenzyme A synthase 2 (HMGCS2), encoding a metabolic enzyme in the liver important for energy production from fatty acids, that shows an unusual expression pattern in developing fetal mouse gonads. Shortly after gonadal sex determination it is up-regulated in the developing testes following a very similar spatial and temporal pattern as the male-determining gene Sry in Sertoli cells before switching to ovarian enriched expression. To test if Hmgcs2 is important for gonad development in mammals, we pursued two lines of investigations. Firstly, we generated Hmgcs2-null mice using CRISPR/Cas9 and found that these mice had gonads that developed normally even on a sensitized background. Secondly, we screened 46,XY DSD patients with gonadal dysgenesis and identified two unrelated patients with a deletion and a deleterious missense variant in HMGCS2 respectively. However, both variants were heterozygous, suggesting that HMGCS2 might not be the causative gene. Analysis of a larger number of patients in the future might shed more light into the possible association of HMGCS2 with human gonadal development.

Evaluation of the abdominopelvic region using MRI in patients with primary amenorrhea.

Background This study aimed to evaluate the imaging findings of patients who underwent an abdominal and pelvic magnetic resonance imaging (MRI) due to primary amenorrhea. Methods The pelvic and abdominal images of 34 female patients (mean age 15.61 years, range 14-19 years) were retrospectively analyzed by a single radiologist blinded to the clinical and laboratory data of the patients (other than primary amenorrhea) to evaluate the etiology of primary amenorrhea. The anatomy and anomalies of the internal genital organs and other accompanying abdominopelvic anomalies were investigated. Results Gonadal dysgenesis was present in 14 patients (41.17%) and Müllerian duct anomalies (MDAs) were present in 20 (58.83%) (Mayer-Rokitansky-Kuster-Hauser [MRKH] syndrome in 13 [65%], distal vaginal obstruction [DVO] findings in five [25%], and obstructed hemivagina and ipsilateral renal anomaly [OHVIRA] syndrome in two [10%]). Seven patients with MRKH (53.84%) were of type 1 and six (46.15%) were of type 2. A total of eight additional anomalies (vertebral and renal) were detected, six in MRKH and two in OHVIRA syndrome cases. Endometrioma and hematosalpinx were observed in one of the five patients with DVO (5%). Conclusions Primary amenorrhea is a common symptom that affects both the physical and psychosocial status of individuals. Determination of the underlying etiology is the first step in planning treatment. The evaluation of internal genital organ anomalies involved in the etiology is important for sexual function and fertility. MRI is a non-invasive imaging modality that should be preferred in these cases as it provides detailed data about the anatomy and anomalies of internal genital organs due to its high soft tissue contrast resolution.

Evaluation of the testis function of mice exposed in utero and during lactation to Pfaffia glomerata (Brazilian ginseng).

Pfaffia glomerata (Spreng.) Pedersen, popularly known as "Brazilian ginseng," is used as medicinal plant in Brazil to treat inflammatory diseases in general. Previous studies showed that its extract increases the nitric oxide (NO) levels. Knowing that NO downregulates steroidogenesis and that alterations in the action/production of androgens during perinatal life could alter testis development, the present studies sought to investigate the reproductive toxicity of Pfaffia glomerata on male mice exposed to hydroalcoholic extract in utero and during lactation. The present study shows that P. glomerata extract does not alter body weight, tubular diameter and testis function in male mice. Although a reduction in the testis weight was observed in the animals that received the highest dose directly in early post-natal life, our findings show clearly that P. glomerata may not act as an endocrine disruptor, and it is not an "antiandrogenic" compound that could lead to testicular dysgenesis syndrome.

Genome-wide identification, evolution of DNA methyltransferases and their expression during gonadal development in Nile tilapia.

DNA methyltransferases (dnmts) are responsible for DNA methylation and play important roles in organism development. In this study, seven dnmts genes (dnmt1, dnmt2, dnmt3aa, dnmt3ab, dnmt3ba, dnmt3bb.1, dnmt3bb.2) were identified in Nile tilapia. Comprehensive analyses of dnmts were performed using available genome databases from representative animal species. Phylogenetic analysis revealed that the dnmts family were highly conserved in teleosts. Based on transcriptome data from eight adult tilapia tissues, the dnmts were found to be dominantly expressed in the head kidney, testis and ovary. Analyses of the gonadal transcriptome data in different developmental stages revealed that all dnmts were expressed in both ovary and testis, and four de novo dnmts (dnmt3aa, dnmt3ab, dnmt3bb.1, dnmt3bb.2) showed higher expression in the testis than in the ovary. Furthermore, during sex reversal induced by Fadrozole, the expression of these four de novo dnmts increased significantly in treated group compared to female control group. By in situ hybridization, the seven dnmts were found to be expressed mainly in phase I and II oocytes of the ovary and spermatocytes of the testis. When gonads were incubated with a methyltransferase inhibitor (5-AzaCdR) in vitro, the expression of dnmts genes were down-regulated significantly, while the expression of cyp19a1a (a key gene in female pathway) and dmrt1 (a key gene in male pathway) increased significantly. Our results revealed the conservation of dnmts during evolution and indicated a potential role of dnmts in epigenetic regulation of gonadal development.

Classical gonadoblastoma: its relationship to the 'dissecting' variant and undifferentiated gonadal tissue.

Classical gonadoblastoma occurs almost entirely in the dysgenetic gonads of an individual who has a disorder of sex development. Approximately 40% of such neoplasms are bilateral. Almost all gonadoblastomas occur in patients who have a Y chromosome or part thereof; testis-specific protein Y-encoded 1 (TSPY1) is the putative gene. If a gonad in a patient who has a disorder of sex development contains germ cells with delayed maturation, and also harbours the TSPY1 gene, the cells can undergo transformation to classical gonadoblastoma. The latter consists of rounded islands composed of germ cells, sex cord elements and hyaline basement membrane material surrounded by a variably cellular gonadal stroma that sometimes contains steroid cells. Classical gonadoblastoma can be interpreted as a non-invasive neoplasm that is the precursor of germinoma and, indirectly, other more aggressive germ cell neoplasms. Undifferentiated gonadal tissue is the precursor of classical gonadoblastoma and contains germ cells with delayed maturation that express octamer-binding transcription factor 4 (OCT4); however, other germ cells show normal maturation and express TSPY1. If all germ cells in a patient with undifferentiated gonadal tissue involute, the result is a secondary streak. Undifferentiated gonadal tissue is a non-neoplastic condition that should be distinguished clearly from 'dissecting gonadoblastoma', a neoplasm derived from classical gonadoblastoma that is the precursor of some germinomas. 'Dissecting gonadoblastoma' is a variant of classical gonadoblastoma that has unusual growth patterns and contains both sex cord and germ cell elements. Clonal expansion of germ cells is a characteristic of the late stage of 'dissecting gonadoblastoma'.

Is testicular dysgenesis syndrome a genetic, endocrine, or environmental disease, or an unexplained reproductive disorder?

Progressive increases in the incidence of male reproductive disorders inclusive of hypospadias, cryptorchidism, poor semen quality, and testicular germ cell cancer (TGCC) have been observed in recent times. The central hypothesis of this study asserted that these disorders may all collectively signify testicular dysgenesis syndrome (TDS). This review aimed to provide evidence verifying the reality of TDS based on four key aspects: environmental endocrine-disrupting chemicals (EDCs), genetic factors, intrauterine growth disorders and lifestyle factors. Although TDS might result from genetic polymorphisms or aberration, recent evidence has highlighted links indicating the conditions associations to both environmental and lifestyle factors due to the rapid temporal changes in the clinical symptoms observed over recent decades. Based on our review of genetic and environmental factors, a key observation of our study suggested that there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. At present, current research has yet to elucidate the mechanisms of TDS, in addition to the lack of genuine consideration of a variety of potentially key factors and TDS mechanisms. In conclusion, our study revealed that environmental exposures owing to modern lifestyles are primary factors involved in the associated trends of the syndrome, which are capable of affecting the adult endocrine system via direct means or through epigenetic mechanisms.

Gonadal dysgenesis is associated with worse outcomes in patients with ovarian nondysgerminomatous tumors: A report of the Children's Oncology Group AGCT 0132 study.

PURPOSE: In this report, we characterize the timing and behavior of malignant ovarian germ cell tumors (GCTs) in pediatric patients with dysgenetic gonads compared to those with normal gonadal development. PATIENTS AND METHODS: Patients from the Children's Oncology Group AGCT0132 with malignant ovarian GCTs were included. Within this population, we sought to identify patients with gonadoblastoma, streak ovaries, or other evidence of gonadal dysgenesis (GD). Patients with malignant GCTs containing one or more of the following histologies-yolk sac tumor, embryonal carcinoma, or choriocarcinoma-were included. Patients were compared with respect to event-free survival (EFS) and overall survival (OS). RESULTS: Nine patients with GD, including seven with gonadoblastoma (mean age, 9.3 years), were compared to 100 non-GD patients (mean age, 12.1 years). The estimated 3-year EFS for patients with GD was 66.7% (95% CI 28.2-87.8%) and for non-GD patients was 88.8% (95% CI 80.2-93.8%). The estimated 3-year OS for patients with GD was 87.5% (95% CI 38.7-98.1%) and for non-GD patients was 97.6% (95% CI of 90.6-99.4%). CONCLUSION: Patients presenting with nongerminomatous malignant ovarian GCTs in the context of GD have a higher rate of events and death than counterparts with normal gonads. These findings emphasize the importance of noting a contralateral streak ovary or gonadoblastoma at histology for any ovarian GCT and support the recommendation for early bilateral gonadectomy in patients known to have GD with Y chromosome material. In contrast to those with pure dysgerminoma, these patients may represent a high-risk group that requires a more aggressive chemotherapy regimen.

Revisiting the human seminiferous epithelium cycle.

STUDY QUESTION: Can all types of testicular germ cells be accurately identified by microscopy techniques and unambiguously distributed in stages of the human seminiferous epithelium cycle (SEC)? SUMMARY ANSWER: By using a high-resolution light microscopy (HRLM) method, which enables an improved visualization of germ cell morphological features, we identified all testicular germ cells in the seminiferous epithelium and precisely grouped them in six well-delimitated SEC stages, thus providing a reliable reference source for staging in man. WHAT IS ALREADY KNOWN: Morphological characterization of germ cells in human has been done decades ago with the use of conventional histological methods (formaldehyde-based fixative -Zenker-formal- and paraffin embedding). These early studies proposed a classification of the SEC in six stages. However, the use of stages as baseline for morphofunctional evaluations of testicular parenchyma has been difficult because of incomplete morphological identification of germ cells and their random distribution in the human SEC. STUDY DESIGN, SIZE, DURATION: Testicular tissue from adult and elderly donors with normal spermatogenesis according to Levin's, Johnsen's and Bergmann's scores were used to evaluate germ cell morphology and validate their distribution and frequency in stages throughout human spermatogenesis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Testicular tissue from patients diagnosed with congenital bilateral agenesis of vas deferens (n = 3 adults) or prostate cancer (n = 3 elderly) were fixed in glutaraldehyde and embedded in araldite epoxy resin. Morphological analyses were performed by both light and transmission electron microscopy. MAIN RESULTS AND THE ROLE OF CHANCE: HRLM method enabled a reliable morphological identification of all germ cells (spermatogonia, spermatocytes and spermatids) based on high-resolution aspects of euchromatin, heterochromatin and nucleolus. Moreover, acrosomal development of spermatids was clearly revealed. Altogether, our data redefined the limits of each stage leading to a more reliable determination of the SEC in man. LIMITATIONS, REASONS FOR CAUTION: Occasionally, germ cells can be absent in some tubular sections. In this situation, it has to be taken into account the germ cell association proposed in the present study to classify the stages. WIDER IMPLICATIONS OF THE FINDINGS: Our findings bring a new focus on the morphology and development of germ cells during the SEC in human. Application of HRLM may be a valuable tool for research studies and clinical andrology helping to understand some testicular diseases and infertility conditions which remain unsolved. STUDY FUNDING/COMPETING INTEREST: Experiments were partially supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo à Pesquisa de Minas Gerais (FAPEMIG) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). The authors declare that there are no conflicts of interest. TRIAL REGISTRATION NUMBER: Not applicable.

Genetics of primary ovarian insufficiency.

Primary ovarian insufficiency (POI) is characterized by a loss of ovarian function before the age of 40 and account for one major cause of female infertility. POI relevance is continuously growing because of the increasing number of women desiring conception beyond 30 years of age, when POI prevalence is >1%. POI is highly heterogeneous and can present with ovarian dysgenesis and primary amenorrhea, or with secondary amenorrhea, and it can be associated with other congenital or acquired abnormalities. In most cases POI remains classified as idiopathic. However, the age of menopause is an inheritable trait and POI has a strong genetic component. This is confirmed by the existence of several candidate genes, experimental and natural models. The variable expressivity of POI defect may indicate that, this disease may frequently be considered as a multifactorial or oligogenic defect. The most common genetic contributors to POI are the X chromosome-linked defects. Here, we review the principal X-linked and autosomal genes involved in syndromic and non-syndromic forms of POI with the expectation that this list will soon be upgraded, thus allowing the possibility to predict the risk of an early age at menopause in families with POI.

Human sex development: targeted technologies to improve diagnosis.

A new study of disorders of sex development presents an improved targeted next-generation sequencing approach for their diagnosis.Please see related Research article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-1105-y .

Cytotype Regulation Facilitates Repression of Hybrid Dysgenesis by Naturally Occurring KP Elements in Drosophila melanogaster.

P elements inserted in the Telomere Associated Sequences (TAS) at the left end of the X chromosome are determiners of cytotype regulation of the entire P family of transposons. This regulation is mediated by Piwi-interacting (pi) RNAs derived from the telomeric P elements (TPs). Because these piRNAs are transmitted maternally, cytotype regulation is manifested as a maternal effect of the TPs. When a TP is combined with a transgenic P element inserted at another locus, this maternal effect is strengthened. However, when certain TPs are combined with transgenes that contain the small P element known as KP, stronger regulation arises from a zygotic effect of the KP element. This zygotic effect is observed with transgenic KP elements that are structurally intact, as well as with KP elements that are fused to an ancillary promoter from the hsp70 gene. Zygotic regulation by a KP element occurs only when a TP was present in the maternal germ line, and it is more pronounced when the TP was also present in the grand-maternal germ line. However, this regulation does not require zygotic expression of the TP These observations can be explained if maternally transmitted piRNAs from TPs enable a polypeptide encoded by KP elements to repress P element transposition in zygotes that contain a KP element. In nature, repression by the KP polypeptide may therefore be facilitated by cytotype-mediating piRNAs.