Disorders/differences Of Sex Development Research Articles

Risk of gonadal neoplasia in patients with disorders/differences of sex development

BackgroundPatients with disorders/differences of sex development (DSD), especially those possessing the Y chromosome, have a higher risk of gonadal germ-cell tumours (GCTs). We aimed to examine the incidence of different types of gonadal neoplasia and associated risk factors. MethodsA total of 1040 DSD patients aged ≥16 years participated in a cross-sectional multicentre European study (dsd-LIFE). Data on medical history were gathered from the patients’ archival medical documents. A web-based questionnaire was filled out individually by the participants. A physical examination was performed in all, while ultrasonography of gonads was carried out in 214 and semen analysis was performed for 53 patients. ResultsGerm-cell neoplasia was present in 12 % of patients with DSD and in 14 % of those with XY DSD. The highest risk (36 %) was observed in 46,XY patients with gonadal dysgenesis (GD): complete GD (33 %) and partial GD (23 %), but also in mixed GD (8 %) and complete androgen insensitivity syndrome (AIS) (6%). It was not reported in partial AIS, XX male, 46,XX DSD and congenital adrenal hyperplasia, Turner and Klinefelter syndromes, or in androgen biosynthesis defects. Benign sex cord-stromal tumours (Sertoli- and Leydig-cell tumours) were noted only in patients with complete AIS (3.1 %) and Klinefelter syndrome (14.3 %). A relationship between risk factors for GCT and gonadal neoplasia appearance, other than the Y chromosome, was not found. ConclusionAdult patients with GD and the Y chromosome have the highest risk of GCT and should be kept under thorough medical control and receive special medical follow-up to prevent the development of gonadal tumours.

Impact of cell-free DNA screening on parental knowledge of fetal sex and disorders of sex development.

Discrepancies between cfDNA and ultrasound predicted fetal sex occur, possibly indicating disorders/differences of sex development (DSDs). Among expectant/recent parents, this study assessed cfDNA knowledge/use, fetal sex determination attitudes/behaviors, general knowledge of DSD, and possible psychological impact of discrepancy between fetal sex on cfDNA and ultrasound. Parents were surveyed about fetal sex determination methods, knowledge of cfDNA and DSD, distress related to possible cfDNA inaccuracy. Of 916 respondents, 44% were aware of possible discrepancy between cfDNA and ultrasound, 22% were aware of DSD. 78% and 75% would be upset and worried, respectively, with results showing fetal sex discrepancy. Most (67%) revealed predicted fetal sex before delivery. 38% were offered cfDNA. Of those revealing fetal sex, 24% used cfDNA results, 71% ultrasound, and 7% both. cfDNA users were more frequently aware of possible discrepancy between cfDNA and ultrasound (76% vs 41%, P < .0001), but not of DSD (29% vs 23%, P = .29). Fetal sex determination is favored, and cfDNA is frequently used for predicting fetal chromosomal sex. Many parents are unaware of possible discrepancies between cfDNA and ultrasound, and potential for DSD. Most would be distressed by discordant results. Accurate counseling regarding limitations cfDNA for fetal sex determination is needed.

A guide to differences/disorders of sex development/intersex in children and adolescents.

Differences/disorders of sex development (DSD) or 'intersex' encompass a broad range of congenital variations in the complex pathways involved in the development of sex characteristics. Components of these pathways include sex chromosomes, genes involved in gonadal development, hormone production and action, and the development of internal and external genital structures. Many variations are rare, and some (eg congenital adrenal hyperplasia) are associated with urgent medical needs. People born with variations in sex characteristics may present in the neonatal period with atypical genitalia, during childhood andadolescence with atypical pubertal development or in adulthood with hormone imbalance, fertility issues and/or sexual health concerns. An overview of DSD is presented in relation to presenting features and management challenges in the paediatric population. An experienced multidisciplinary team that uses a shared decision-making approach with a medical, surgical, ethical,psychological and human rights framework is required to maximise long-term positive outcomes for people born with variations in sex characteristics.

Testis formation in XX individuals resulting from novel pathogenic variants in Wilms’ tumor 1 (WT1) gene

Sex determination in mammals is governed by antagonistic interactions of two genetic pathways, imbalance in which may lead to disorders/differences of sex development (DSD) in human. Among 46,XX individuals with testicular DSD (TDSD) or ovotesticular DSD (OTDSD), testicular tissue is present in the gonad. Although the testis-determining gene SRY is present in many cases, the etiology is unknown in most SRY-negative patients. We performed exome sequencing on 78 individuals with 46,XX TDSD/OTDSD of unknown genetic etiology and identified seven (8.97%) with heterozygous variants affecting the fourth zinc finger (ZF4) of Wilms' tumor 1 (WT1) (p.Ser478Thrfs*17, p.Pro481Leufs*15, p.Lys491Glu, p.Arg495Gln [x3], p.Arg495Gly). The variants were de novo in six families (P = 4.4 × 10-6), and the incidence of WT1 variants in 46,XX DSD is enriched compared to control populations (P < 1.8 × 10-4). The introduction of ZF4 mutants into a human granulosa cell line resulted in up-regulation of endogenous Sertoli cell transcripts and Wt1Arg495Gly/Arg495Gly XX mice display masculinization of the fetal gonads. The phenotype could be explained by the ability of the mutated proteins to physically interact with and sequester a key pro-ovary factor β-CATENIN, which may lead to up-regulation of testis-specific pathway. Our data show that unlike previous association of WT1 and 46,XY DSD, ZF4 variants of WT1 are a relatively common cause of 46,XX TDSD/OTDSD. This expands the spectrum of phenotypes associated with WT1 variants and shows that the WT1 protein affecting ZF4 can function as a protestis factor in an XX chromosomal context.

Post-operative complications following feminizing genitoplasty in moderate to severe genital atypia: Results from a multicenter, observational prospective cohort study

Disorders/differences of sex development (DSD) are congenital conditions in which there is atypical chromosomal, gonadal and/or phenotypic sex. While there remains controversy around the traditionally binary concept of sex, most patients with DSD are reared either male or female depending on their genetic sex, gonadal sex, genital phenotype and status of their internal genital tract. This study uses prospective data from 12 institutions across the United States that specialize in DSD care. We focused on patients raised female. Eligible patients had moderate to severe genital atypia (defined as Prader score >2), were ≤2 years of age at entry, and had no prior genitoplasty. The aim of this study is to describe early post operative complications for young patients undergoing modern approaches to feminizing genitoplasty. Of the 91 participants in the cohort, 57 (62%) were reared female. The majority had congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (n=52), 1 had ovo-testicular syndrome, 2 had mixed gonadal dysgenesis and 2 had partial androgen insensitivity syndrome (PAIS). Of the 50 participants who received early genitoplasty, 43 (86%) had follow-up at 6-12 months post-surgery. Thirty-two participants (64%) received a clitoroplasty, 31 (62%) partial urogenital mobilization and 4 (8%) total urogenital sinus mobilization. Eighteen percent (9/50) experienced post-surgical complications with 7 (14%) being rated as Clavien-Dindo grade III. Both parents and surgeons reported improved satisfaction with genital appearance of participants following surgery compared to baseline. This information on post-operative complications associated with contemporary approaches to feminizing genitoplasty performed in young children will help guide families when making decisions about whether or not to proceed with surgery for female patients with moderate to severe genital atypia.

CYP17A1 deficient XY mice display susceptibility to atherosclerosis, altered lipidomic profile and atypical sex development

CYP17A1 is a cytochrome P450 enzyme with 17-alpha-hydroxylase and C17,20-lyase activities. CYP17A1 genetic variants are associated with coronary artery disease, myocardial infarction and visceral and subcutaneous fat distribution; however, the underlying pathological mechanisms remain unknown. We aimed to investigate the function of CYP17A1 and its impact on atherosclerosis in mice. At 4–6 months, CYP17A1-deficient mice were viable, with a KO:Het:WT ratio approximating the expected Mendelian ratio of 1:2:1. All Cyp17a1 knockout (KO) mice were phenotypically female; however, 58% were Y chromosome-positive, resembling the phenotype of human CYP17A1 deficiency, leading to 46,XY differences/disorders of sex development (DSD). Both male and female homozygous KO mice were infertile, due to abnormal genital organs. Plasma steroid analyses revealed a complete lack of testosterone in XY-KO mice and marked accumulation of progesterone in XX-KO mice. Elevated corticosterone levels were observed in both XY and XX KO mice. In addition, Cyp17a1 heterozygous mice were also backcrossed onto an Apoe KO atherogenic background and fed a western-type diet (WTD) to study the effects of CYP17A1 on atherosclerosis. Cyp17a1 x Apoe double KO XY mice developed more atherosclerotic lesions than Apoe KO male controls, regardless of diet (standard or WTD). Increased atherosclerosis in CYP17A1 XY KO mice lacking testosterone was associated with altered lipid profiles. In mice, CYP17A1 deficiency interferes with sex differentiation. Our data also demonstrate its key role in lipidomic profile, and as a risk factor in the pathogenesis of atherosclerosis.

OR27-01 Combining Clinical and Genetic Approaches in Diagnosing a Large Brazilian Cohort of Patients with 46,XY Differences/Disorders of Sex Development (DSD)

Background: It is recommended a multidisciplinary approach consisted of clinical, hormonal and genetic workups for diagnosing 46,XY DSD. However, no previous study has quantified how useful is this combined approach. Objectives: To retrospectively review the clinical and genetic findings for diagnosing a large cohort of patients with 46,XY DSD from a single Brazilian center. Methods: 247 non-syndromic 46,XY DSD individuals (159 sporadic and 88 familial cases from 39 families) were studied. Clinical and hormonal data were collected from medical files. Testosterone (T), androstenedione (A) were measured by immunoradiometric or immunofluorimetric assays and dihydrotestosterone (DHT) by RIA after celite chromatography or by liquid chromatography tandem mass spectrometry; T/DHT and T/A ratios were calculated. Analysis of sensitivity (SE), specificity (SP) of T/DHT was performed, being the molecular diagnosis considered the gold standard for diagnosing SRD5A2 deficiency. A T/A>0.8 was considered indicative of 17ß-HSDB3 deficiency. The patients were clinically classified into four subgroups: 1) androgen insensitivity syndrome (AIS), 2) gonadal dysgenesis (GD); 3) defects in androgen synthesis (DAS) and 4) DSD of unknown etiology. Molecular studies were performed by Sanger sequencing and/ or massively parallel sequencing (MPS). Results: The median age at first visit was 14 years (range 0.1 to 59 years). The molecular diagnosis was established in 96.5% of the cases with AIS (n=28/29), in 96% of the subjects with DAS (n=46/48), in 36% of the patients with GD (n=21/57) and in 26.7% (n=15/56) with DSD of unknown etiology. The best cut-off for T/DHT in basal state and hCG stimulated was 12.5 (SE=100%; SP=78.57%) and 24 (SE=87.5%; SP=95.7%) respectively. A T/A<0.8 was observed in 13/16 (81%) of the patients with molecular diagnosis of 17ß-HSDB3 deficiency and also in 1/49 patients with other diagnose. Classification according to the phenotype matched with the genetic diagnosis in most cases. The molecular evaluation allowed that 16% (9/56) of the patients that were classified as DSD of unknow etiology had a definitive diagnosis, including six GD cases, two individuals with SRD5A2 deficiency and one with 17ß-HSDB3 deficiency. A clear AIS phenotype of five patients allowed us to consider and prove the pathogenicity of two synonymous and one promoter region variants as the cause of AIS. The combination of clinical and molecular diagnosis led to an increase in 8% the diagnosis in a total of 116 index-cases (58.5%) with a molecular diagnosis. Conclusion: Considering the phenotype heterogeneity, pitfalls of the hormonal assessment and number of genes involved, it is reasonable to consider MPS as a first test for diagnosing patients with 46,XY DSD. However, the combination of clinical and molecular diagnosis is more accurate than either strategies alone in diagnosing 46,XY DSD.

OR27-02 An Exploration of Novel Clinical Benchmarks for Assessing the Practice of Gonadectomy in Conditions Affecting Sex Development - on Behalf of the I-DSD Consortium

Introduction: Although the practice of gonadectomy in the field of differences/disorders of sex development (DSD) has undergone intense scrutiny, objective knowledge regarding current practice of gonadectomy is lacking in conditions affecting sex development. Methods: The International DSD Registry (www.I-DSD.org) was examined for clinical information reported by the DSD specialist centre on age at presentation, year of birth, diagnosis, karyotype, sex of rearing and age at gonadectomy in all cases over the age of 16 years at the time of search and who had a disorder of androgen action or synthesis, gonadal dysgenesis or a non-specific DSD.Results: Of the 3,618 cases available in the registry, 757 (21%) met the inclusion criteria and data regarding gonadectomy status were available in 668 (88%) from 44 participating centres. Of these, 248 (37%) with a median age of 24 years (range 17, 75) were registered as male and 420 (63%) with a median age of 26 years (16, 86) were registered as female. Gonadectomy was reported from 36 centres in 351 of these 668 cases (53%) of whom 302 (86%) had a 46 XY karyotype. Females were more likely to undergo gonadectomy (n=311, p<0.0001) and the most common diagnoses were complete androgen insensitivity syndrome (n=161, 24%) and partial gonadal dysgenesis (n=94, 14%). Of the 351 cases, the primary indication for gonadectomy was reported in 268 (76%) cases and included mitigation of tumourigenesis risk in 172 (64%), conformity to sex assignment in 74 (28%) and another indication in 22 (8%). Gonadectomy was bilateral in 295 (84%), unilateral in 16 (5%) and unknown in 40 (11%). The median ratio for age at first presentation to age at gonadectomy in those who presented before the age of 5 years and those who presented after the age of 10 years was 0.1 (range) and 0.9 (range), respectively (p<0.0001). Of the 351 cases, 17 (5%) had undergone a gonadectomy before their first presentation to the specialist centre and these cases were distributed across 9 of the 36 centres. Conclusions: Not only does the rate of gonadectomy vary according to underlying diagnosis and sex of rearing, it also seems that there is a variable discrepancy between the age at presentation and age at gonadectomy. The use of this objective marker to identify trends in practice may improve our understanding of the causes of variation.

An Intersectional Approach to Understanding Potential Health Disparities in Adolescents with a Disorder of Sex Development/Intersex

Background: Stigma and lack of social and parental support during adolescence can have life-long effects on health and well-being for adolescents. Adolescents with disorders/differences of sex development (DSD) may experience amplified effects. Further, such patients face numerous increased social and health. Studies of patients with DSD indicate theye experience adverse pscyhosocial outcomes similar to LGB and gender non-conforming populations (i.e. increased depressive symptoms, anxiety, self-harming behaviors, and substance abuse).

Female hyperandrogenism and elite sport.

Emerging evidence indicates that testosterone, which can increase muscle mass and strength, stimulates erythropoiesis, promotes competitive behaviour, and enhances the physical performance of women. Indeed, the levels of testosterone within the normal female range are related to muscle mass and athletic performance in female athletes. Furthermore, among these athletes, the prevalence of hyperandrogenic conditions, including both polycystic ovary syndrome and rare differences/disorders of sex development (DSD), which may greatly increase testosterone production, are elevated. Thus, if the androgen receptors of an individual with XY DSD are functional, her muscle mass will develop like that of a man. These findings have led to the proposal that essential hyperandrogenism is beneficial for athletic performance and plays a role in the choice by women to compete in athletic activities. Moreover, a recent randomized controlled trial demonstrated a significant increase in the lean mass and aerobic performance by young exercising women when their testosterone levels were enhanced moderately. Circulating testosterone is considered the strongest factor to explain the male advantage in sport performance, ranging between 10 and 20%. It appears to be unfair to allow female athletes with endogenous testosterone levels in the male range (i.e. 10–20 times higher than normal) to compete against those with normal female androgen levels. In 2012, this consideration led international organizations to establish eligibility regulations for the female classification in order to ensure fair and meaningful competition, but the regulations are controversial and have been challenged in court.

Oligogenic Origin of Differences of Sex Development in Humans.

Sex development is a very complex biological event that requires the concerted collaboration of a large network of genes in a spatial and temporal correct fashion. In the past, much has been learned about human sex development from monogenic disorders/differences of sex development (DSD), but the broad spectrum of phenotypes in numerous DSD individuals remains a conundrum. Currently, the genetic cause of less than 50% of DSD individuals has been solved and oligogenic disease has been proposed. In recent years, multiple genetic hits have been found in individuals with DSD thanks to high throughput sequencing. Our group has been searching for additional genetic hits explaining the phenotypic variability over the past years in two cohorts of patients: 46,XY DSD patients carriers of NR5A1 variants and 46,XY DSD and 46,XX DSD with MAMLD1 variants. In both cohorts, our results suggest that the broad phenotypes may be explained by oligogenic origin, in which multiple hits may contribute to a DSD phenotype, unique to each individual. A search for an underlying network of the identified genes also revealed that a considerable number of these genes showed interactions, suggesting that genetic variations in these genes may affect sex development in concert.

Parent-reported outcomes in young children with disorders/differences of sex development

BackgroundThere is a paucity of tools that can be used in routine clinical practice to assess the psychosocial impact of Disorders/Differences of Sex Development (DSD) on parents and children.ObjectiveTo evaluate the use of short Parent Self-Report and Parent Proxy-Report questionnaires that can be used in the outpatient setting.MethodsPreviously validated DSD-specific and generic items were combined to develop a Parent Self-Report questionnaire and a Parent Proxy-Report questionnaire for children under 7 years. Of 111 children approached at one tertiary paediatric hospital, the parents of 95 children (86%) with DSD or other Endocrine conditions completed these questionnaires.ResultsQuestionnaires took under 10 min to complete and were found to be easy to understand. Compared to reference, fathers of children with DSD reported less stress associated with Clinic Visits (p = 0.02) and managing their child’s Medication (p = 0.04). However, parents of children with either DSD or other Endocrine conditions reported more symptoms of Depression (p = 0.03). Mothers of children with DSD reported greater Future Concerns in relation to their child’s condition (median SDS − 0.28; range − 2.14, 1.73) than mothers of children with other Endocrine conditions (SDS 1.17; − 2.00, 1.73) (p = 0.02). Similarly, fathers of children with DSD expressed greater Future Concerns (median SDS -1.60; − 4.21, 1.00) than fathers of children with other Endocrine conditions (SDS 0.48; − 2.13, 1.52) (p = 0.04).ConclusionDSD was associated with greater parental concerns over the child’s future than other Endocrine conditions. Brief parent-report tools in DSD can be routinely used in the outpatient setting to assess and monitor parent and patient needs.

Analysis of variants in GATA4 and FOG2/ZFPM2 demonstrates benign contribution to 46,XY disorders of sex development.

BackgroundGATA‐binding protein 4 (GATA4) and Friend of GATA 2 protein (FOG2, also known as ZFPM2) form a heterodimer complex that has been shown to influence transcription of genes in a number of developmental systems. Recent evidence has also shown these genes play a role in gonadal sexual differentiation in humans. Previously we identified four variants in GATA4 and an unexpectedly large number of variants in ZFPM2 in a cohort of individuals with 46,XY Differences/Disorders of Sex Development (DSD) (Eggers et al, Genome Biology, 2016; 17: 243).MethodHere, we review variant curation and test the functional activity of GATA4 and ZFPM2 variants. We assess variant transcriptional activity on gonadal specific promoters (Sox9 and AMH) and variant protein–protein interactions.ResultsOur findings support that the majority of GATA4 and ZFPM2 variants we identified are benign in their contribution to 46,XY DSD. Indeed, only one variant, in the conserved N‐terminal zinc finger of GATA4, was considered pathogenic, with functional analysis confirming differences in its ability to regulate Sox9 and AMH and in protein interaction with ZFPM2.ConclusionsOur study helps define the genetic factors contributing to 46,XY DSD and suggests that the majority of variants we identified in GATA4 and ZFPM2/FOG2 are not causative.

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.

Pathogenic variants in the DEAH-box RNA helicase DHX37 are a frequent cause of 46,XY gonadal dysgenesis and 46,XY testicular regression syndrome

PurposeXY individuals with disorders/differences of sex development (DSD) are characterized by reduced androgenization caused, in some children, by gonadal dysgenesis or testis regression during fetal development. The genetic etiology for most patients with 46,XY gonadal dysgenesis and for all patients with testicular regression syndrome (TRS) is unknown. MethodsWe performed exome and/or Sanger sequencing in 145 individuals with 46,XY DSD of unknown etiology including gonadal dysgenesis and TRS. ResultsThirteen children carried heterozygous missense pathogenic variants involving the RNA helicase DHX37, which is essential for ribosome biogenesis. Enrichment of rare/novel DHX37 missense variants in 46,XY DSD is highly significant compared with controls (P value = 5.8 × 10−10). Five variants are de novo (P value = 1.5 × 10−5). Twelve variants are clustered in two highly conserved functional domains and were specifically associated with gonadal dysgenesis and TRS. Consistent with a role in early testis development, DHX37 is expressed specifically in somatic cells of the developing human and mouse testis. ConclusionDHX37 pathogenic variants are a new cause of an autosomal dominant form of 46,XY DSD, including gonadal dysgenesis and TRS, showing that these conditions are part of a clinical spectrum. This raises the possibility that some forms of DSD may be a ribosomopathy.

Prenatal detection and evaluation of differences of sex development

Differences/disorders of sex development (DSD) can be detected at different ages, including prenatally. The recent implementation of prenatal genetic testing (including cell-free DNA) may affect the frequency and impact of prenatal diagnosis of DSD. Our aims were to(1) describe prenatal detection and evaluation of differences of sex development presenting to a multidisciplinary DSD clinic and (2) explore possible parental distress accompanying this evaluation. A retrospective chart review of mothers presenting prenatally, and patients presenting during infancy, to a multidisciplinary DSD clinic from 2013 to 2017 was conducted. Data extracted included demographics, final diagnoses, prenatal screening, prenatal evaluation, postnatal endocrine, genetic and radiologic testing, and clinician's notes on parent/patient distress. Sixty-seven patients were identified; ten (15%) had prenatal detection of a suspected DSD. Of those, 4/10 were detected prenatally in the last study year alone. Within the prenatal group, 6/10 had cell-free DNA results discordant with ultrasound, 2/10 were detected by atypical genitalia on ultrasound, and 2/10 were detected through karyotyping performed for other indications. After birth, 3/10 patients were found to not have a DSD. Final diagnoses for the full study cohort are shown in the Summary Table, comparing prenatal versus postnatal presentation to our DSD clinic. Clinicians noted distress for most parents during the prenatal evaluation of a possible DSD, including one mother who reported suicidal thoughts. Prenatal suspicion of DSD can occur through discordant prenatal testing and has been observed at our clinic in recent years, in line with other recent studies. Contributing factors to these prenatal presentations could be increased referrals to the clinic, and increased use of non-invasive prenatal testing, which can lead to inaccurate or discordant sex identification. The prenatal suspicion of a potential DSD can be associated with parental distress, underscoring the need for adequate counseling for tests that determine fetal sex, including cell-free DNA.

Male mice lacking ADAMTS-16 are fertile but exhibit testes of reduced weight

Adamts16 encodes a disintegrin-like and metalloproteinase with thrombospondin motifs, 16, a member of a family of multi-domain, zinc-binding proteinases. ADAMTS-16 is implicated in a number of pathological conditions, including hypertension, cancer and osteoarthritis. A large number of observations, including a recent report of human ADAMTS16 variants in cases of 46,XY disorders/differences of sex development (DSD), also implicate this gene in human testis determination. We used CRISPR/Cas9 genome editing to generate a loss-of-function allele in the mouse in order to examine whether ADAMTS-16 functions in mouse testis determination or testicular function. Male mice lacking Adamts16 on the C57BL/6N background undergo normal testis determination in the fetal period. However, adult homozygotes have an average testis weight that is around 10% lower than age-matched controls. Cohorts of mutant males tested at 3-months and 6-months of age were fertile. We conclude that ADAMTS-16 is not required for testis determination or male fertility in mice. We discuss these phenotypic data and their significance for our understanding of ADAMTS-16 function.

Mutation update for the NR5A1 gene involved in DSD and infertility.

Nuclear receptor subfamily 5 group A member 1 (NR5A1), also named steroidogenic factor 1, is an essential transcription factor that regulates a number of target genes crucial for normal reproductive physiology and endocrine function. It is encoded by NR5A1 gene and is expressed in high doses mainly in steroidogenic tissues, where it controls several steps of adrenal and gonadal development. NR5A1 mutations are associated with a wide phenotypic spectrum of disorders/differences of sex development (DSD), a group of conditions in which development of chromosomal, gonadal, or anatomic sex is atypical. Here, we reviewed 188 NR5A1 mutations from 238 cases reported in literature so far. Additionally, we report the variations p.Ser4*, p.(Cys55Ser), p.(Met78Leu), and p.Met98Glyfs*45, which have not been annotated for NR5A1 before and were identified in some of the 205 46,XY patients of our own cohort. This is the first NR5A1 mutation review which includes both 46,XX and 46,XY karyotype, with the purpose of discussing the complexity of genotype-phenotype correlations among DSD and infertile male patients and also females with primary ovarian failure.

Clinical management in mixed gonadal dysgenesis with chromosomal mosaicism: Considerations in newborns and adolescents

Individuals born on the spectrum of genetic abnormalities known as mixed gonadal dysgenesis (MGD) have a wide range of anatomical findings and management can be challenging in the newborn and adolescent. Historically, many individuals with MGD have undergone gonadectomy to avert the risk of gonadal malignancy. However, gonadectomy deprives patients of the benefits of their endogenous hormones, potential fertility, and in the case with MGD, has historically been done prior to addressing gender identity. Some patient advocates have proposed a delayed approach to surgical reconstructions and/or gonadectomy in other differences/disorders of sex development (DSD), particularly in patients with congenital adrenal hyperplasia and androgen insensitivity syndrome. In many areas of the world, there continues to be a shift toward delayed reconstructions and hesitancy regarding irreversible gonadectomy. To date, no clinical management protocol addressing these issues from a patient-centered approach has been described. We review what is known about malignancy risk and propose a management protocol for those with MGD that involves shared decision making regarding the gonads and addresses the long-term challenges with regard to gender and anatomy.

Assembling the jigsaw puzzle: CBX2 isoform 2 and its targets in disorders/differences of sex development

Background One of the defining moments of human life occurs early during embryonic development, when individuals sexually differentiate into either male or female. Perturbation of this process can lead to disorders/differences of sex development (DSD). Chromobox protein homolog 2 (CBX2) has two distinct isoforms, CBX2.1 and CBX2.2: the role of CBX2.1 in DSD has been previously established, yet to date the function of the smaller isoform CBX2.2 remains unknown. Methods The genomic DNA of two 46,XY DSD patients was analysed using whole exome sequencing. Furthermore, protein/DNA interaction studies were performed using DNA adenine methyltransferase identification (DamID) to identify putative binding partners of CBX2. Finally, in vitro functional studies were used to elucidate the effect of wild-type and variant CBX2.2 on selected downstream targets. Results Here, we describe two patients with features of DSD i.e. atypical external genitalia, perineal hypospadias and no palpable gonads, each patient carrying a distinct CBX2.2 variant, p.Cys132Arg (c.394T>C) and p.Cys154fs (c.460delT). We show that both CBX2.2 variants fail to regulate the expression of genes essential for sexual development, leading to a severe 46,XY DSD defect, likely because of a defective expression of EMX2 in the developing gonad. Conclusion Our study indicates a distinct function of the shorter form of CBX2 and by identifying several of its unique targets, can advance our understanding of DSD pathogenesis and ultimately DSD diagnosis and management.