Next generation sequencing (NGS) to improve the diagnosis and management of patients with disorders of sex development (DSD)

46, XY under-virilization and NR5A1 variants: Monocentric Indian experience and systematic review

PURPOSE

NR5A1 variants are rare causes of 46,XY DSD with scarce literature from India. A systematic review of genotype-phenotype correlation is lacking. We aim to describe clinical, biochemical, histological, and genotype-phenotype correlation in 46,XY DSD with NR5A1 variants.

METHODS

Retrospective monocentric review of 11 genetically-proven probands and systematic review including these and 288 from the literature.

RESULTS

Eleven probands of 46,XY DSD with NR5A1 variants from our centre exhibited phenotypic variability, female-to-male social-gender change in ∼two-thirds (4/7), primary adrenal insufficiency (PAI) in one, and five novel variants. Systematic review included 299 probands (age: 4.0 [0.3-13] years; Sinnecker score: 4 [3-4]) with 218 different NR5A1 variants. Systematic review reported female-to-male gender-change (27/166, 16.3%), spontaneous puberty/pubertal virilization (37/86, 43%), DSD in siblings (25/299, 8.3%), paternal hypospadias (7/299, 2.3%), maternal premature ovarian insufficiency (19/299, 6.4%), bilateral labio-scrotal gonads (71/214, 33.2%), absent Mullerian structure (187/232, 80.6%), PAI (5/222, 2.2%) and gonadal malignancy (2/111, 1.8%) in probands. Serum LH was elevated in mini-puberty, pre-puberty, and peri/post-puberty in 35.4% (17/48), 46.2% (18/39), and 63.6% (49/77) patients, respectively. Germ cells were present in 55.6% (5/9) in mini-pubertal age and absent in 96.8% (61/63) at later age. Sertoli cells were reported normal in 100% (7/7), and 70.4% (38/54) in mini-pubertal and later ages, respectively. Presence of Mullerian structures and Sinnecker score of 4/5 were associated with LBD variants (54.5%vs. 30.6%, P=0.003) and protein start-lost/deletion (7.3% vs. nil, P=0.004), respectively.

CONCLUSIONS

46,XY DSD with NR5A1 variants is characterized by progressive decline in Sertoli and Leydig cell function, pubertal virilization, frequent partial gonadal dysgenesis and probably lower gonadal malignancy risk than gonadal dysgenesis of other origin. Further studies are warranted to validate these observations.

Genetic and genomic insights into male reproductive tract development

Genetic and genomic analysis continues to drive important insights into male reproductive tract (MRT) development. Here, we briefly review normal MRT development, highlighting recent discoveries of cell types and cellular processes delivered by single-cell sequencing. We report a systematic review of phenotype terms and genes linked to MRT development, identifying 35 terms from the Human Phenotype Ontology associated with 269 unique genes. A parallel review of mouse data revealed differences in the phenotype terms available and the number and identity of genes linked to MRT defects, indicating opportunities for harmonization of knowledge. We used a published single-cell atlas of the developing testis to characterize the regulation of MRT genes across cell types and stages of fetal testis development. Single-cell RNA sequencing data support the conclusion that Leydig cells and Sertoli cells are the primary testicular cell types expressing MRT genes. Furthermore, we find post-conception weeks 6, 8, and 16 to be the key points of upregulation of testicular MRT genes. New advances, especially in imaging and spatially resolved molecular measurements, provide exciting prospects for MRT research and diagnosis, and we expect rapid progress in the coming years. Continued investigation in this space is essential to understand the genetic basis of MRT development and how MRT defects are related to medical outcomes in adult life.

Oligogenic analysis across broad phenotypes of 46,XY differences in sex development associated with NR5A1/SF-1 variants: findings from the international SF1next study

BACKGROUND

Oligogenic inheritance has been suggested as a possible mechanism to explain the broad phenotype observed in individuals with differences of sex development (DSD) harbouring NR5A1/SF-1 variants.

METHODS

We investigated genetic patterns of possible oligogenicity in a cohort of 30 individuals with NR5A1/SF-1 variants and 46,XY DSD recruited from the international SF1next study, using whole exome sequencing (WES) on family trios whenever available. WES data were analysed using a tailored filtering algorithm designed to identify rare variants in DSD and SF-1-related genes. Identified variants were subsequently tested using the Oligogenic Resource for Variant Analysis (ORVAL) bioinformatics platform for a possible combined pathogenicity with the individual NR5A1/SF-1 variant.

FINDINGS

In 73% (22/30) of the individuals with NR5A1/SF-1 related 46,XY DSD, we identified one to seven additional variants, predominantly in known DSD-related genes, that might contribute to the phenotype. We found identical variants in eight unrelated individuals with DSD in DSD-related genes (e.g., TBCE, FLNB, GLI3 and PDGFRA) and different variants in eight genes frequently associated with DSD (e.g., CDH23, FLNB, GLI2, KAT6B, MYO7A, PKD1, SPRY4 and ZFPM2) in 15 index cases. Our study also identified combinations with NR5A1/SF-1 variants and variants in novel candidate genes.

INTERPRETATION

These findings highlight the complex genetic landscape of DSD associated with NR5A1/SF-1, where in several cases, the use of advanced genetic testing and filtering with specific algorithms and machine learning tools revealed additional genetic hits that may contribute to the phenotype.

FUNDING

Swiss National Science Foundation and Boveri Foundation Zurich.

Clinical utility of anti-Müllerian hormone in female children and adolescents

Anti-Müllerian hormone (AMH) is a dimeric glycoprotein that belongs to the transforming growth factor beta superfamily and plays essential roles in sexual differentiation and folliculogenesis. In the male embryo, AMH is produced by the Sertoli cells and induces the involution of the Müllerian ducts. In females, AMH is predominately produced by the granulosa cells of growing preantral and small antral follicles and regulates follicular maturation. Many recent studies have highlighted the significant role of this hormone in the diagnostic approach to female children and adolescents with various disorders that affect ovarian development and function. AMH is considered a valuable diagnostic tool in the management of female pediatric patients with conditions such as polycystic ovary syndrome, precocious puberty, ovarian tumors, differences in sex development, and premature ovarian insufficiency. Standardization of AMH assays, internationally approved reference values based on age and pubertal stage, and widespread availability of the test could further upgrade the clinical utility of AMH, rendering it a valuable tool in the armamentarium of physicians involved in the care of female children and adolescents, and promote future research.

Persistent Müllerian Duct Syndrome with Supernumerary Testicles Due to a Novel Homozygous Variant in the AMHR2 Gene and Literature Review

Introduction: Persistent Müllerian duct syndrome (PMDS) is a rare disorder of sex development (DSD) caused by mutations in the genes coding anti-Müllerian hormone (AMH) or the AMH receptor, characterized by the persistence of Müllerian derivatives, the uterus and/or fallopian tubes, in otherwise normally virilized boys. Testicular regression syndrome is common in PMDS, yet the association with supernumerary testis has been reported in only two patients where genetic testing was not performed. Method: Thus, we report an individual with this particular association caused by a previously unreported homozygous variant in the AMHR2 gene to enable future genotype-phenotype correlations in this rare disorder. In addition, a search of PMDS associated with congenital anomalies reported in the literature was performed to provide a comprehensive overview of this pathology. Results: We present the case of a 13-year-old boy with a history of bilateral cryptorchidism. Two attempts of right orchidopexy were performed at the age of 4 and 5 years. At that time, exploratory laparoscopy identified an intra-abdominal left testicle. In addition, a fibrous structure extending from the left intra-abdominal testicle to the deep inguinal ring (Müllerian duct remnants) and a medially located abdominal mass, bilaterally fixated to the parietal peritoneum (uterine remnant), were detected. The left testicular biopsy revealed immature prepubertal testicular tissue. The uterine remnant was dissected and removed and the left orchidopexy was performed. The karyotype was 46, XY without other numerical or structural chromosomal abnormalities. Reinterventions on the left testicle were performed at the age of 9 and 12 years when a testicular remnant was identified in the left inguinal canal and removed. Three months after left orchidectomy, ultrasound followed by abdominopelvic MRI identified a structure resembling a testis in the left inguinal area. Another surgical exploration was performed, and a mass located outside (lateral) the inguinal canal was found. A biopsy from the suspected mass was performed. The histopathologic examination showed characteristics of immature prepubertal testis. The patient was later referred to our clinic with the suspicion of DSD. Serum AMH and inhibin B were normal. Therefore, the diagnosis of PMDS was suspected. Genetic testing was performed using next-generation sequencing in a gene panel that included AMH and AMHR2 genes. A homozygous variant classified as likely pathogenic in the AMHR2 gene was identified but remains unreported in the literature (NC_000012.11:g.53823315T>C in exon 8 of the AMHR2 gene). Conclusions: A high degree of suspicion and awareness is needed to diagnose this condition in order to avoid iterative surgery. The coexistence of two extremely rare conditions (PMDS and supernumerary testes) has been reported previously in only two patients, yet the association could have a common pathophysiologic background. Our case, reporting a novel AMHR2 variant, highlights the importance of genetic testing in these individuals in order to elucidate a possible genotype-phenotype correlation.

Genetic and Clinical Characteristics of 185 Japanese Children with 46,XY Differences of Sex Development

CONTEXT

46,XY differences of sex development (DSD) are heterogeneous in etiology. The detailed phenotypes of 46,XY DSD patients with monogenic disorders have not been fully elucidated.

OBJECTIVES

To estimate the proportion of monogenic disorders in 46,XY DSD and to characterize the clinical phenotypes of patients with monogenic disorders.

METHODS

A total of 185 Japanese patients (178 families) were enrolled. We sequenced 25 genes related to 46,XY DSD, and assessed the pathogenicity of the identified sequence variants according to the American College of Medical Genetics and Genomics guidelines, supplemented by in silico or in vitro analyses. We analyzed the clinical phenotypes of patients with monogenic disorders, with particular attention to the external or internal genitalia.

RESULTS

We identified 51 patients (47 families) with any monogenic disorders (26%), who possessed pathogenic variants in AR (11%), SRD5A2 (4.5%), NR5A1 (4.0%), SRY (2.8%), WT1 (1.1%), STAR (1.1%), CYP17A1 (0.56%), HSD3B2 (0.56%), or MAP3K1 (0.56%). The proportion of monogenic disorders was significantly higher in subjects with detected Müllerian derivatives (57%) than in those undetected (26%) (P = 0.029), in subjects with female-typical genitalia (91%) than those with ambiguous genitalia (19%) (P < 0.001).

CONCLUSIONS

The proportion of monogenic disorders in Japanese 46,XY DSD patients was approximately 26%. Monogenic disorders were frequent among patients with severe undermasculinization of the external or internal genitalia.

NR5A1/SF-1 Collaborates with Inhibin α and the Androgen Receptor

Steroidogenic factor 1 (SF-1) is a nuclear receptor that regulates steroidogenesis and reproductive development. NR5A1/SF-1 variants are associated with a broad spectrum of phenotypes across individuals with disorders of sex development (DSDs). Oligogenic inheritance has been suggested as an explanation. SF-1 interacts with numerous partners. Here, we investigated a constellation of gene variants identified in a 46,XY severely undervirilized individual carrying an ACMG-categorized 'pathogenic' NR5A1/SF-1 variant in comparison to the healthy carrier father. Candidate genes were revealed by whole exome sequencing, and pathogenicity was predicted by different in silico tools. We found variants in NR1H2 and INHA associated with steroidogenesis, sex development, and reproduction. The identified variants were tested in cell models. Novel SF-1 and NR1H2 binding sites in the AR and INHA gene promoters were found. Transactivation studies showed that wild-type NR5A1/SF-1 regulates INHA and AR gene expression, while the NR5A1/SF-1 variant had decreased transcriptional activity. NR1H2 was found to regulate AR gene transcription; however, the NR1H2 variant showed normal activity. This study expands the NR5A1/SF-1 network of interacting partners, while not solving the exact interplay of different variants that might be involved in revealing the observed DSD phenotype. It also illustrates that understanding complex genetics in DSDs is challenging.

Evidence for NR2F2/COUP-TFII involvement in human testis development

NR2F2 encodes COUP-TFII, an orphan nuclear receptor required for the development of the steroidogenic lineages of the murine fetal testes and ovaries. Pathogenic variants in human NR2F2 are associated with testis formation in 46,XX individuals, however, the function of COUP-TFII in the human testis is unknown. We report a de novo heterozygous variant in NR2F2 (c.737G > A, p.Arg246His) in a 46,XY under-masculinized boy with primary hypogonadism. The variant, located within the ligand-binding domain, is predicted to be highly damaging. In vitro studies indicated that the mutation does not impact the stability or subcellular localization of the protein. NR5A1, a related nuclear receptor that is a key factor in gonad formation and function, is known to physically interact with COUP-TFII to regulate gene expression. The mutant protein did not affect the physical interaction with NR5A1. However, in-vitro assays demonstrated that the mutant protein significantly loses the inhibitory effect on NR5A1-mediated activation of both the LHB and INSL3 promoters. The data support a role for COUP-TFII in human testis formation. Although mutually antagonistic sets of genes are known to regulate testis and ovarian pathways, we extend the list of genes, that together with NR5A1 and WT1, are associated with both 46,XX and 46,XY DSD.

Cytogenomic description of a Mexican cohort with differences in sex development

BACKGROUND

Differences in Sex Development (DSD) is a heterogeneous group of congenital alterations that affect inner and/or outer primary sex characters. Although these conditions do not represent a mortality risk, they can have a severe psycho-emotional impact if not appropriately managed. The genetic changes that can give rise to DSD are diverse, from chromosomal alterations to single base variants involved in the sexual development network. Epidemiological studies about DSD indicate a global frequency of 1:4500-5500, which can increase to 1:200-300, including isolated anatomical defects. To our knowledge, this study is the first to describe epidemiological and genetic features of DSD in a cohort of Mexican patients of a third-level care hospital.

METHODS

Descriptive and retrospective cross-sectional study that analyzed DSD patients from 2015 to 2021 attended a Paediatric Hospital from Mexico City.

RESULTS

One hundred one patients diagnosed with DSD were registered and grouped into different entities according to the Chicago consensus statement and the diagnosis defined by the multidisciplinary group. Of the total, 54% of them belong to the chromosomal DSD classification, 16% belongs to 46, XX and 30% of them belongs to the 46, XY classification.

CONCLUSION

The frequency for chromosomal DSDs was consistent with the literature; however, we found that DSD 46, XY is more frequent in our cohort, which may be due to the age of the patients captured, the characteristics of our study population, or other causes that depend on the sample size.

Worldwide cohort study of 46, XY differences/disorders of sex development genetic diagnoses: geographic and ethnic differences in variants

Differences/disorders of sex development (DSDs) in individuals with a 46, XY karyotype are a group of congenital disorders that manifest as male gonadal hypoplasia or abnormalities of the external genitalia. Approximately 50% of patients with 46, XY DSDs cannot obtain a molecular diagnosis. The aims of this paper were to review the most common causative genes and rare genes in patients with 46, XY DSDs, analyze global molecular diagnostic cohorts for the prevalence and geographic distribution of causative genes, and identify the factors affecting cohort detection results. Although the spectrum of genetic variants varies across regions and the severity of the clinical phenotype varies across patients, next-generation sequencing (NGS), the most commonly used detection method, can still reveal genetic variants and aid in diagnosis. A comparison of the detection rates of various sequencing modalities revealed that whole-exome sequencing (WES) facilitates a greater rate of molecular diagnosis of the disease than panel sequencing. Whole-genome sequencing (WGS), third-generation sequencing, and algorithm advancements will contribute to the improvement of detection efficiency. The most commonly mutated genes associated with androgen synthesis and action are AR, SR5A2, and HSD17B3, and the most commonly mutated genes involved in gonadal formation are NR5A1 and MAP3K1. Detection results are affected by differences in enrollment criteria and sequencing technologies.

Clinical, Hormonal, and Genetic Spectrum of 46 XY Disorders of Sexual Development (DSD) Patients

OBJECTIVES

To evaluate the clinical, hormonal and genetic characteristics of 46XY disorders of sexual development (DSD) patients from South India.

METHODS

46XY DSD patients with a provisional diagnosis of 17β-hydroxysteroid dehydrogenase 3 (17BHSD3) deficiency, 5 alpha-reductase type 2 deficiency (5ARD2) or partial androgen insensitivity syndrome (PAIS) based on clinical and hormonal analysis were included in this study. All the patients underwent detailed clinical and hormonal evaluations. Targeted next-generation sequencing for all three genes (AR, HSD17B3, and SRD5A2) in parallel was carried out for all the included patients and their parents.

RESULTS

Based upon the clinical and hormonal analysis, among the 37 children with 46XY DSD in the present study, 21 children were diagnosed with 5ARD2, 10 with PAIS, and six with 17BHSD3 deficiency. However, genetic analysis revealed pathogenic mutations in nine patients - six in the AR gene, two in the SRD5A2 gene, and one in the HSD17B3 gene. The concordance rate between provisional hormonal and genetic diagnosis was only 22.2%. Two out of six subjects with AR gene variants were positive for somatic mosaicism.

CONCLUSIONS

In the present study, a positive genetic diagnosis was detected in nine patients (24%), including five novel variants. In this study, mutations in the AR gene was the most reported. The authors did not find the testosterone: dihydrotestosterone (T: DHT) ratio to be an accurate hormonal diagnostic tool.

[Clinical, hormonal and molecular genetic characteristics of patients with 46,XY disorders of sex development associated with variants in the HSD17B3 gene]

BACKGROUND

Deficiency of 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) is a rare variant of 46,XY disorders of sex development (DSD).

AIM

To give clinical, hormonal and molecular genetic characteristics of cases of 46,XY DSD associated with variants in the HSD17B3 gene.

MATERIALS AND METHODS

The study included 310 patients with 46,XY DSD for the period from 2015 to 2019. The patients underwent a comprehensive examination, including a study of the steroid profile by high-performance liquid chromatography with tandem mass spectrometric detection, as well as a molecular genetic analysis using NGS.

RESULTS

According to the results of molecular genetic studies, biallelic nucleotide substitutions in the HSD17B3 gene were detected in 13 cases, which accounted for 4.2% of the total number of patients with 46,XY DSD. All 13 patients with biallelic variants in the HSD17B3 gene were registered as females. The ratio of androstenedione/testosterone concentrations in the blood in this group ranged from 1.4 to 8.9. 2 variants in the HSD17B3 gene were found in several patients: c.277+4A>T (on 6 chromosomes) and c.729_735del:p.V243fs (on 9 chromosomes). 4 novel variants have been identified. Monoallelic nucleotide substitutions in the HSD17B3 gene were detected in 7 cases, which accounted for 2.3% of the total number of patients with 46,XY DSD. External genitalia in this group corresponded to Prader stages 3-4. In 1 patient, a pathogenic variant c.277+4A>T was detected in the HSD17B3 gene, in other cases variants with uncertain significance were detected.

CONCLUSION

In the structure of 46,XY DSD, patients with biallelic variants in the HSD17B3 gene were identified in 4.2% of cases, with monoallelic variants - in 2.3% of cases. 4 novel variants were found in the HSD17B3 gene.

Serum steroid metabolite profiling by LC-MS/MS in two phenotypic male patients with HSD17B3 deficiency: Implications for hormonal diagnosis

Although 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) deficiency is diagnosed when a testosterone/androstenedione (T/A-dione) ratio after human chorionic gonadotropin (hCG) stimulation is below 0.8, this cut-off value is primarily based on hormonal data measured by conventional immunoassay (IA) in patients with feminized or ambiguous genitalia. We examined two 46,XY Japanese patients with undermasculinized genitalia including hypospadias (patient 1 and patient 2). Endocrine studies by IA showed well increased serum T value after hCG stimulation (2.91 ng/mL) and a high T/A-dione ratio (4.04) in patient 1 at 2 weeks of age and sufficiently elevated basal serum T value (2.60 ng/mL) in patient 2 at 1.5 months of age. Despite such partial androgen insensitivity syndrome-like findings, whole exome sequencing identified biallelic ″pathogenic″ or ″likely pathogenic″ variants in HSD17B3 (c .188 C>T:p.(Ala63Val) and c .194 C>T:p.(Ser65Leu) in patient 1, and c.139 A>G:p.(Met47Val) and c.672 + 1 G>A in patient 2) (NM_000197.2), and functional analysis revealed reduced HSD17B3 activities of the missense variants (∼ 43% for p.Met47Val, ∼ 14% for p.Ala63Val, and ∼ 0% for p.Ser65Leu). Thus, we investigated hCG-stimulated serum steroid metabolite profiles by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in patient 1 at 7 months of age and in patient 2 at 11 months of age as well as in five control males with idiopathic micropenis aged 1 - 8 years, and found markedly high T/A-dione ratios (12.3 in patient 1 and 5.4 in patient 2) which were, however, obviously lower than those in the control boys (25.3 - 56.1) and sufficiently increased T values comparable to those of control males. The elevated T/A-dione ratios are considered be due to the residual HSD17B3 function and the measurement by LC-MS/MS. Thus, it is recommended to establish the cut-off value for the T/A-dione ratio according to the phenotypic sex reflecting the residual function and the measurement method.

Individuals with numerical and structural variations of sex chromosomes: interdisciplinary management with focus on fertility potential

Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present. Many individuals with Klinefelter syndrome (47XXY) remain undiagnosed or are only diagnosed as adults due to fertility problems. Newborn screening by heel prick tests could potentially identify sex chromosome variations but would have ethical and financial implications, and in-depth cost-benefit analyses are needed before nationwide screening can be introduced. Most individuals who have NSVSC have lifelong co-morbidities and healthcare should be holistic, personalized and centralized, with a focus on information, psychosocial support and shared decision-making. Fertility potential should be assessed individually and discussed at an appropriate age. Oocyte or ovarian tissue cryopreservation is possible in some women who have Turner syndrome and live births have been reported following assisted reproductive technology (ART). Testicular sperm cell extraction (TESE) is possible in some men who have 45,X/46,XY mosaicism, but there is no established protocol and no reported fathering of children. Some men with Klinefelter syndrome can now father a child following TESE and ART, with multiple reports of healthy live births. Children who have NSVSC, their parents and DSD team members need to address possibilities and ethical questions relating to potential fertility preservation, with guidelines and international studies still needed.

Nuclear Receptor Gene Variants Underlying Disorders/Differences of Sex Development through Abnormal Testicular Development

Gonadal development is the first step in human reproduction. Aberrant gonadal development during the fetal period is a major cause of disorders/differences of sex development (DSD). To date, pathogenic variants of three nuclear receptor genes (NR5A1, NR0B1, and NR2F2) have been reported to cause DSD via atypical testicular development. In this review article, we describe the clinical significance of the NR5A1 variants as the cause of DSD and introduce novel findings from recent studies. NR5A1 variants are associated with 46,XY DSD and 46,XX testicular/ovotesticular DSD. Notably, both 46,XX DSD and 46,XY DSD caused by the NR5A1 variants show remarkable phenotypic variability, to which digenic/oligogenic inheritances potentially contribute. Additionally, we discuss the roles of NR0B1 and NR2F2 in the etiology of DSD. NR0B1 acts as an anti-testicular gene. Duplications containing NR0B1 result in 46,XY DSD, whereas deletions encompassing NR0B1 can underlie 46,XX testicular/ovotesticular DSD. NR2F2 has recently been reported as a causative gene for 46,XX testicular/ovotesticular DSD and possibly for 46,XY DSD, although the role of NR2F2 in gonadal development is unclear. The knowledge about these three nuclear receptors provides novel insights into the molecular networks involved in the gonadal development in human fetuses.

A novel c.64G > T (p.G22C) NR5A1 variant in a Chinese adolescent with 46,XY disorders of sex development: a case report

BACKGROUND

Adolescents with 46,XY disorders of sex development (DSD) face additional medical and psychological challenges. To optimize management and minimize hazards, correct and early clinical and molecular diagnosis is necessary.

CASE PRESENTATION

We report a 13-year-old Chinese adolescent with absent Müllerian derivatives and suspected testis in the inguinal area. History, examinations, and assistant examinations were available for clinical diagnosis of 46,XY DSD. The subsequent targeting specific disease-causing genes, comprising 360 endocrine disease-causing genes, was employed for molecular diagnosis. A novel variation in nuclear receptor subfamily 5 group A member 1 (NR5A1) [c.64G > T (p.G22C)] was identified in the patient. In vitro functional analyses of the novel variant suggested no impairment to NR5A1 mRNA or protein expression relative to wild-type, and immunofluorescence confirmed similar localization of NR5A1 mutant to the cell nucleus. However, we observed decreased DNA-binding affinity by the NR5A1 variant, while dual-luciferase reporter assays showed that the mutant effectively downregulated the transactivation capacity of anti-Müllerian hormone. We described a novel NR5A1 variant and demonstrated its adverse effects on the functional integrity of the NR5A1 protein resulting in serious impairment of its modulation of gonadal development.

CONCLUSIONS

This study adds one novel NR5A1 variant to the pool of pathogenic variants and enriches the adolescents of information available about the mutation spectrum of this gene in Chinese population.

Cocktails of NSAIDs and 17α Ethinylestradiol at Environmentally Relevant Doses in Drinking Water Alter Puberty Onset in Mice Intergenerationally

Non-steroidal anti-inflammatory drugs (NSAIDs) and 17α-ethinyl-estradiol (EE2) are among the most relevant endocrine-disrupting pharmaceuticals found in the environment, particularly in surface and drinking water due to their incomplete removal via wastewater treatment plants. Exposure of pregnant mice to NSAID therapeutic doses during the sex determination period has a negative impact on gonadal development and fertility in adults; however, the effects of their chronic exposure at lower doses are unknown. In this study, we investigated the impact of chronic exposure to a mixture containing ibuprofen, 2hydroxy-ibuprofen, diclofenac, and EE2 at two environmentally relevant doses (added to the drinking water from fetal life until puberty) on the reproductive tract in F1 exposed mice and their F2 offspring. In F1 animals, exposure delayed male puberty and accelerated female puberty. In post-pubertal F1 testes and ovaries, differentiation/maturation of the different gonad cell types was altered, and some of these modifications were observed also in the non-exposed F2 generation. Transcriptomic analysis of post-pubertal testes and ovaries of F1 (exposed) and F2 animals revealed significant changes in gene expression profiles and enriched pathways, particularly the inflammasome, metabolism and extracellular matrix pathways, compared with controls (non-exposed). This suggested that exposure to these drug cocktails has an intergenerational impact. The identified Adverse Outcome Pathway (AOP) networks for NSAIDs and EE2, at doses that are relevant to everyday human exposure, will improve the AOP network of the human reproductive system development concerning endocrine disruptor chemicals. It may serve to identify other putative endocrine disruptors for mammalian species based on the expression of biomarkers.

Diagnostic approach in 46, XY DSD: an endocrine society of bengal (ESB) consensus statement

OBJECTIVES

46, XY difference/disorder of sex development (DSD) is a relatively uncommon group of heterogeneous disorders with varying degree of underandrogenization of male genitalia. Such patients should be approached systematically to reach an aetiological diagnosis. However, we lack, at present, a clinical practice guideline on diagnostic approach in 46, XY DSD from this part of the globe. Moreover, debate persists regarding the timing and cut-offs of different hormonal tests, performed in these cases. The consensus committee consisting of 34 highly experienced endocrinologists with interest and experience in managing DSD discussed and drafted a consensus statement on the diagnostic approach to 46, XY DSD focussing on relevant history, clinical examination, biochemical evaluation, imaging and genetic analysis.

CONTENT

The consensus was guided by systematic reviews of existing literature followed by discussion. An initial draft was prepared and distributed among the members. The members provided their scientific inputs, and all the relevant suggestions were incorporated. The final draft was approved by the committee members.

SUMMARY

The diagnostic approach in 46, XY DSD should be multidisciplinary although coordinated by an experienced endocrinologist. We recommend formal Karyotyping, even if Y chromosome material has been detected by other methods. Meticulous history taking and thorough head-to-toe examination should initially be performed with focus on external genitalia, including location of gonads. Decision regarding hormonal and other biochemical investigations should be made according to the age and interpreted according to age-appropriate norms Although LC-MS/MS is the preferred mode of steroid hormone measurements, immunoassays, which are widely available and less expensive, are acceptable alternatives. All patients with 46, XY DSD should undergo abdominopelvic ultrasonography by a trained radiologist. MRI of the abdomen and/or laparoscopy may be used to demonstrate the Mullerian structure and/or to localize the gonads. Genetic studies, which include copy number variation (CNV) or molecular testing of a candidate gene or next generation sequencing then should be ordered in a stepwise manner depending on the clinical, biochemical, hormonal, and radiological findings.

OUTLOOK

The members of the committee believe that patients with 46, XY DSD need to be approached systematically. The proposed diagnostic algorithm, provided in the consensus statement, is cost effective and when supplemented with appropriate genetic studies, may help to reach an aetiological diagnosis in majority of such cases.

Pathological variants in genes associated with disorders of sex development and central causes of hypogonadism in a whole-genome reference panel of 8380 Japanese individuals

Disorders of sex development (DSD) comprises a congenital condition in which chromosomal, gonadal, or anatomical sex development is atypical. In this study, we screened for pathogenic variants in 32 genes associated with DSDs and central causes of hypogonadism (CHG) in a whole-genome reference panel including 8380 Japanese individuals constructed by Tohoku Medical Megabank Organization. Candidate pathogenic (P) or likely pathogenic (LP) variants were extracted from the ClinVar, InterVar, and Human Gene Mutation databases. Ninety-one candidate pathological variants were found in 25 genes; 28 novel candidate variants were identified. Nearly 1 in 40 (either ClinVar or InterVar P or LP) to 157 (both ClinVar and InterVar P or LP) individuals were found to be carriers of recessive DSD and CHG alleles. In these data, genes implicated in gonadal dysfunction did not show loss-of-function variants, with a relatively high tendency of intolerance for haploinsufficiency based on pLI and Episcore, both of which can be used for estimating haploinsufficiency. We report the types and frequencies of causative variants for DSD and CHG in the general Japanese population. This study furthers our understanding of the genetic causes and helps to refine genetic counseling of DSD and CHG.

Disorder of Sex Development Due to 17-Beta-Hydroxysteroid Dehydrogenase Type 3 Deficiency: A Case Report and Review of 70 Different HSD17B3 Mutations Reported in 239 Patients

The 17-beta-hydroxysteroid dehydrogenase type 3 (17-β-HSD3) enzyme converts androstenedione to testosterone and is encoded by the HSD17B3 gene. Homozygous or compound heterozygous HSD17B3 mutations block the synthesis of testosterone in the fetal testis, resulting in a Disorder of Sex Development (DSD). We describe a child raised as a female in whom the discovery of testes in the inguinal canals led to a genetic study by whole exome sequencing (WES) and to the identification of a compound heterozygous mutation of the HSD17B3 gene (c.608C>T, p.Ala203Val, and c.645A>T, p.Glu215Asp). Furthermore, we review all HSD17B3 mutations published so far in cases of 17-β-HSD3 deficiency. A total of 70 different HSD17B3 mutations have so far been reported in 239 patients from 187 families. A total of 118 families had homozygous mutations, 63 had compound heterozygous mutations and six had undetermined genotypes. Mutations occurred in all 11 exons and were missense (55%), splice-site (29%), small deletions and insertions (7%), nonsense (5%), and multiple exon deletions and duplications (2%). Several mutations were recurrent and missense mutations at codon 80 and the splice-site mutation c.277+4A>T each represented 17% of all mutated alleles. These findings may be useful to those involved in the clinical management and genetic diagnosis of this disorder.

Novel Genomic Variants, Atypical Phenotypes and Evidence of a Digenic/Oligogenic Contribution to Disorders/Differences of Sex Development in a Large North African Cohort

In a majority of individuals with disorders/differences of sex development (DSD) a genetic etiology is often elusive. However, new genes causing DSD are routinely reported and using the unbiased genomic approaches, such as whole exome sequencing (WES) should result in an increased diagnostic yield. Here, we performed WES on a large cohort of 125 individuals all of Algerian origin, who presented with a wide range of DSD phenotypes. The study excluded individuals with congenital adrenal hypoplasia (CAH) or chromosomal DSD. Parental consanguinity was reported in 36% of individuals. The genetic etiology was established in 49.6% (62/125) individuals of the total cohort, which includes 42.2% (35/83) of 46, XY non-syndromic DSD and 69.2% (27/39) of 46, XY syndromic DSD. No pathogenic variants were identified in the 46, XX DSD cases (0/3). Variants in the AR, HSD17B3, NR5A1 and SRD5A2 genes were the most common causes of DSD. Other variants were identified in genes associated with congenital hypogonadotropic hypogonadism (CHH), including the CHD7 and PROKR2. Previously unreported pathogenic/likely pathogenic variants (n = 30) involving 25 different genes were identified in 22.4% of the cohort. Remarkably 11.5% of the 46, XY DSD group carried variants classified as pathogenic/likely pathogenic variant in more than one gene known to cause DSD. The data indicates that variants in PLXNA3, a candidate CHH gene, is unlikely to be involved in CHH. The data also suggest that NR2F2 variants may cause 46, XY DSD.

17β hydroxysteroid dehydrogenase 3 deficiency in 46,XY disorders of sex development: Our experience and a gender role-focused systematic review

OBJECTIVES

To describe Asian Indian patients with 17β hydroxysteroid dehydrogenase 3 (17βHSD3) deficiency and to perform a systematic review to determine the factors influencing gender role in 46,XY disorder of sex development (DSD) due to 17βHSD3 deficiency.

PATIENTS AND DESIGN

We present the phenotypic and genotypic data of 10 patients (9 probands and 1 affected family member) with 17βHSD3 deficiency from our 46,XY DSD cohort (N = 150; Western India) and a systematic review of 152 probands with genetically proven, index 17βHSD3 deficiency patients from the world literature to identify the determinants of gender role.

RESULTS

17βHSD3 deficiency was the third most common (6%) cause of non-dysgenetic 46,XY DSD in our cohort. Five patients each had prepubertal (atypical genitalia) and pubertal (primary amenorrhoea) presentations. Six patients were initially reared as female of whom two (one each in prepubertal and pubertal age) changed their gender role. Ten pathogenic molecular variants (six novel) were observed. In the systematic review, initial male sex of rearing was uncommon (10.5%) and was associated with atypical genitalia, higher testosterone/androstenedione (T/A) ratio and Asian origin. Gender role change to male was seen in 10.3% of patients with initial female sex of rearing and was associated with Asian origin but unrelated to pubertal androgens or molecular variant severity. It has not been reported in patients of European origin.

CONCLUSIONS

We report the first Indian case series of 17βHSD3 deficiency, the third most common cause of 46,XY DSD, with six novel molecular variants. Distinct geographical differences in the frequency of initial male sex of rearing and gender role change to male in those initially reared as females in 17βHSD3 deficiency were noted which needs further evaluation for the underlying molecular mechanisms.

46,XY disorders of sex development: the use of NGS for prevalent variants

46,XY disorders of sex development (DSD) present with diverse phenotypes and complicated genetic causes. Precise genetic diagnosis contributes to accurate management, and targeted next-generation sequencing (NGS) and whole-exome sequencing are powerful tools for investigating DSD. However, the prevalent variants resulting in 46,XY DSD remain unclear, especially those associated with mild forms, such as isolated hypospadias, inguinal cryptorchidism, and micropenis. From 2019 to 2021, 74 patients with 46,XY DSD (48 typical and 26 mild) from the First Affiliated Hospital of Sun Yat-sen University were enrolled in our cohort study for targeted NGS or whole-exome sequencing. Our targeted 46,XY DSD panel included 108 genes involved in disorders of gonadal development and differentiation, steroid hormone synthesis and activation, persistent Müllerian duct syndrome, idiopathic hypogonadotropic hypogonadism, syndromic disorder, and others. Variants were classified as pathogenic, likely pathogenic, variant of uncertain significance, likely benign, or benign following the American College of Medical Genetics guidelines. As a result, 28 of 74 (37.8%) patients with pathogenic and/or likely pathogenic variants acquired genetic diagnoses. The Mild DSD patients acquired a diagnosis rate of 30.7%. We detected 44 variants in 28 DSD genes from 31 patients, including 33 novel and 11 reported variants. Heterozygous (65%) and missense (70.5%) variants were the most common. Variants associated with steroid hormone synthesis and activation were the main genetic causes of 46,XY DSD. In conclusion, 46,XY DSD manifests as a series of complicated polygenetic diseases. NGS reveals prevalent variants and improves the genetic diagnoses of 46,XY DSD, regardless of severity.

Temporal sociomedical approaches to intersex* bodies

The history of the field of intersex bodies/bodies with variations of sex development (VSD) reflects the ongoing tension between sociomedical attempts to control uncertainty and reduce the duration of corporeal uncertainty by means of early diagnosis and treatment, and the embodied subjects who resist or challenge these attempts, which ultimately increase uncertainty. Based on various qualitative studies in the field of intersex, this article describes three temporal sociomedical approaches that have evolved over the last decade and aims to address the uncertainty surrounding intersex/VSD bodies. These approaches are (1) the corrective-concealing approach, which includes early surgeries and hormone therapies intended to "correct" intersex conditions and the deliberate concealment of the ambiguity and uncertainty associated with intersex conditions; (2) the preventive approach, which involves early genetic diagnostic methods aimed at regulating or preventing the recurrence of hereditary conditions under the umbrella of VSD; and (3) the wait-and-see approach, which perceives intersex bodies as natural variations and encourages parents to take time, wait, and give their children the right to bodily autonomy. A comparison of these approaches from biopolitical, phenomenological, and pragmatic perspectives reveals that time is an essential social agent in addressing and controlling uncertainty, a gatekeeper of social norms and social and physical orders, and, on the other hand, a sociopolitical agent that enables creative social change.

Delivery of multidisciplinary care in the field of differences and disorders of sex development (DSD)

INTRODUCTION

Differences and disorders of sex development (DSD) are a diverse group of conditions, which often present in early childhood and may require input from a group of experts in a wide range of clinical fields. Clinical guidance in this field recommends that these experts function as a multidisciplinary team (MDT) within which each expert has a defined role, which ensures an integrated and streamlined approach to the care of affected individuals.

AREAS COVERED

This review will focus on the benefits of multidisciplinary care for people with DSD, as well as the challenges that may be faced.

EXPERT OPINION

Core members of the MDT for people with DSD include endocrinologists, surgeons, psychologists, geneticists, specialist nurses, radiologists, and gynecologists, although many other health-care professionals may also be pertinent, at different stages of the patient's life. With greater acceptance of remote and digital health-care technology, there is a need to review the traditional concepts of the clinical MDT so that new care models can be explored for effective and efficient delivery of complex care.

Genomic variants reducing expression of two endocytic receptors in 46,XY differences of sex development

Transporter-dependent steroid hormone uptake into target cells was demonstrated in genetically engineered mice and fruit flies. We hypothesized that mutations in such transporters may cause differences in sex development (DSD) in humans. Exome sequencing was performed in 16 genetically unsolved cases of 46,XY DSD selected from an anonymized collection of 708 lines of genital fibroblasts (GF) that were taken from individuals with incomplete virilization. Selection criteria were based on available biochemical characterization of GF compatible with reduced androgen uptake. Two unrelated individuals were identified with mutations in LDL receptor-related protein 2 (LRP2), a gene previously associated with partial sex steroid insensitivity in mice. Like Lrp2^-/- mice, affected individuals had non-descended testes. Western blots on GF confirmed reduced LRP2 expression, and endocytosis of sex hormone-binding globulin was reduced. In three unrelated individuals, two with undescended testes, mutations in another endocytic receptor gene, limb development membrane protein 1 like (LMBR1L), were detected. Two of these individuals had mutations affecting the same codon. In a transfected cell model, mutated LMBR1L showed reduced cell surface expression. Our findings suggest that endocytic androgen uptake in complex with sex hormone-binding globulin is relevant in human. LMBR1L may play a similar role in androgen uptake.

Disorders of Sex Development in a Large Ukrainian Cohort: Clinical Diversity and Genetic Findings

BACKGROUND

The clinical profile and genetics of individuals with Disorders/Differences of Sex Development (DSD) has not been reported in Ukraine.

MATERIALS AND METHODS

We established the Ukrainian DSD Register and identified 682 DSD patients. This cohort includes, 357 patients (52.3% [303 patients with Turner syndrome)] with sex chromosome DSD, 119 (17.5%) with 46,XY DSD and 206 (30.2%) with 46,XX DSD. Patients with sex chromosome DSD and congenital adrenal hyperplasia (CAH, n=185) were excluded from further studies. Fluorescence in situ hybridization (FISH) was performed for eight 46,XX boys. 79 patients underwent Whole Exome Sequencing (WES).

RESULTS

The majority of patients with 46,XY and 46,XX DSD (n=140), were raised as female (56.3% and 61.9% respectively). WES (n=79) identified pathogenic (P) or likely pathogenic (LP) variants in 43% of the cohort. P/LP variants were identified in the androgen receptor (AR) and NR5A1 genes (20.2%). Variants in other DSD genes including AMHR2, HSD17B3, MYRF, ANOS1, FGFR11, WT1, DHX37, SRD5A1, GATA4, TBCE, CACNA1A and GLI2 were identified in 22.8% of cases. 83.3% of all P/LP variants are novel. 35.3% of patients with a genetic diagnosis had an atypical clinical presentation. A known pathogenic variant in WDR11, which was reported to cause congenital hypogonadotropic hypogonadism (CHH), was identified in individuals with primary hypogonadism.

CONCLUSIONS

WES is a powerful tool to identify novel causal variants in patients with DSD, including a significant minority that have an atypical clinical presentation. Our data suggest that heterozygous variants in the WDR11 gene are unlikely to cause of CHH.

Surgical management and molecular diagnosis of persistent Müllerian duct syndrome in Chinese patients

Persistent Müllerian duct syndrome (PMDS) is a rare clinically and genetically overlapping disorder caused by mutations in the anti-Müllerian hormone (AMH) gene or the anti-Müllerian hormone receptor type 2 (AMHR2) gene. Affected individuals present uterus and tubes in normally virilized males and are discovered unexpectedly during other surgeries. Since it is rare and complex, a definitive clinical diagnosis can be missed, and there are no guidelines regarding how to deal with the uterus. In the present study, exome sequencing and Sanger verification were performed for causal variants in 12 PMDS patients. Preoperative diagnoses were made by positive exome sequencing in 8 patients. Of them, 7 patients evoked on the basis of ultrasound indicating bilateral testes on the same side of the body. Twelve different AMH variants (2 frameshift/nonsense, 1 deletion, 8 missense, and 1 in-frame) in 9 patients and 6 different AMHR2 variants (5 missense and 1 splicing) in 3 patients were identified. Seven variants were classified as "pathogenic" or "likely pathogenic", and 4 of them were novel. All but two patients with AMH defects showed low serum AMH concentrations, but all patients with AMHR2 defects showed elevated AMH levels. During surgery, an abnormal vas deferens was observed in half of the patients. Eight patients underwent orchidopexy with uterine preservation. Of them, 2 patients presented complications including irreducible cryptorchidism, and 3 patients developed Müllerian remnant cysts. Three patients underwent subtotal hysterectomy. Of them, one patient had complication of injury to the vas deferens, and one had hemorrhage after operation. This is the first report of PMDS involving a large Chinese population. The present study not only expands the variation spectrum but also provides clinical experience about the management of the uterus.

Genetics of human sexual development and related disorders

PURPOSE OF REVIEW

The aim of this study was to provide a basic overview on human sex development with a focus on involved genes and pathways, and also to discuss recent advances in the molecular diagnostic approaches applied to clinical workup of individuals with a difference/disorder of sex development (DSD).

RECENT FINDINGS

Rapid developments in genetic technologies and bioinformatics analyses have helped to identify novel genes and genomic pathways associated with sex development, and have improved diagnostic algorithms to integrate clinical, hormonal and genetic data. Recently, massive parallel sequencing approaches revealed that the phenotype of some DSDs might be only explained by oligogenic inheritance.

SUMMARY

Typical sex development relies on very complex biological events, which involve specific interactions of a large number of genes and pathways in a defined spatiotemporal sequence. Any perturbation in these genetic and hormonal processes may result in atypical sex development leading to a wide range of DSDs in humans. Despite the huge progress in the understanding of molecular mechanisms underlying DSDs in recent years, in less than 50% of DSD individuals, the genetic cause is currently solved at the molecular level.

Analysis of the androgen receptor (AR) gene in a cohort of Indonesian undermasculinized 46, XY DSD patients

Background

Pathogenic variants in the androgen receptor (AR) gene located on chromosome Xq11-12, are known to cause varying degrees of undermasculinization in 46, XY individuals. The aim of this study was to investigate the frequency of pathogenic variants in the AR gene in a cohort of 46, XY undermasculinized individuals from Indonesia who were suspected of having androgen insensitivity syndrome (AIS). All patients with 46, XY DSD referred to our center between 1994 and 2019 were collected from our clinical database. All 46, XY DSD patients without a prior molecular diagnosis with an external masculinization score (EMS) ≤ 9 were included in this study. All exons and intron–exon boundaries of AR gene were analyzed using Sanger sequencing to identify pathogenic variants of the AR gene.

Results

A cohort of 75 undermasculinized patients were selected for the study. Direct Sanger sequencing of all eight exons of the AR gene led to a genetic diagnosis in 11 patients (14.67%). All of the variants identified (p.Arg841His; p.Ile604Asn; p.Val731Met; p.Pro672Ser; p.Gln739Arg; p.Ser302Glufs*3) have been previously reported in patients with AIS.

Conclusions

This is the first study in Indonesia that highlights the significance of molecular analysis in providing a definitive diagnosis of AIS for patients with 46, XY DSD undermasculinization. This is an uncommon finding in the Indonesian population presenting with 46, XY DSD undermasculinization. A genetic diagnosis allows optimal clinical management and genetic counseling for patients and their families. As 46, XY DSD can be caused by pathogenic variants in other genes involved in gonadal development and differentiation, further genetic analysis, such as whole exome sequencing, should be carried out on those patients that did not carry an AR variant.

Role of Genetic Counseling for Patients with Hypospadias and Their Families

Congenital malformations often have a genetic background associated with a recurrence risk and may be part of a syndrome. Therefore, for children with a congenital malformation, the parents should be offered genetic counseling, and the child should also be offered the same when they reach adulthood. Hypospadias is a common malformation in boys that arises during genital development in weeks 8 to 16. This results in an underdevelopment of the ventral aspect of the penis with a misplacement of the urethral opening somewhere along the penis, scrotum, or in the perineum and with different degrees of penile curvature. The cause can be monogenic, but generally it is regarded as a complex disorder caused by both genetic and environmental factors. Severe hypospadias and familial cases should be genetically investigated, as for other forms of disorders of sex development, according to current guidelines with sequencing of relevant genes. Hypospadias associated with another independent malformation may be part of a syndrome and should be investigated. Fortunately, boys born with milder hypospadias generally have a good outcome and thus the clinical value of finding a disease-causing mutation appears to be limited especially in light of the present cost of genetic analysis. However, all men born with hypospadias should be advised on the recurrence risk and risk for reduced fertility.

Society for Endocrinology UK Guidance on the initial evaluation of a suspected difference or disorder of sex development (Revised 2021)

It is paramount that any child or adolescent with a suspected difference or disorder of sex development (DSD) is assessed by an experienced clinician with adequate knowledge about the range of conditions associated with DSD and is discussed with the regional DSD service. In most cases, the paediatric endocrinologist within this service acts as the first point of contact but involvement of the regional multidisciplinary service will also ensure prompt access to specialist psychology and nursing care. The underlying pathophysiology of DSD and the process of delineating this should be discussed with the parents and affected young person with all diagnostic tests undertaken in a timely fashion. Finally, for rare conditions such as these, it is imperative that clinical experience is shared through national and international clinical and research collaborations.

El laboratorio en el diagnóstico multidisciplinar del desarrollo sexual anómalo o diferente (DSD)

Objetivos

El desarrollo de las características sexuales femeninas o masculinas acontece durante la vida fetal, determinándose el sexo genético, el gonadal y el sexo genital interno y externo (femenino o masculino). Cualquier discordancia en las etapas de diferenciación ocasiona un desarrollo sexual anómalo o diferente (DSD) que se clasifica según la composición de los cromosomas sexuales del cariotipo.

Contenido

En este capítulo se abordan la fisiología de la determinación y el desarrollo de las características sexuales femeninas o masculinas durante la vida fetal, la clasificación general de los DSD y su estudio diagnóstico clínico, bioquímico y genético que debe ser multidisciplinar. Los estudios bioquímicos deben incluir, además de las determinaciones bioquímicas generales, análisis de hormonas esteroideas y peptídicas, en condiciones basales o en pruebas funcionales de estimulación. El estudio genético debe comenzar con la determinación del cariotipo al que seguirá un estudio molecular en los cariotipos 46,XX ó 46,XY, orientado a la caracterización de un gen candidato. Además, se expondrán de manera específica los marcadores bioquímicos y genéticos en los DSD 46,XX, que incluyen el desarrollo gonadal anómalo (disgenesias, ovotestes y testes), el exceso de andrógenos de origen fetal (el más frecuente), fetoplacentario o materno y las anomalías del desarrollo de los genitales internos.

Perspectivas

El diagnóstico de un DSD requiere la contribución de un equipo multidisciplinar coordinado por un clínico y que incluya los servicios de bioquímica y genética clínica y molecular, un servicio de radiología e imagen y un servicio de anatomía patológica.

Exonic WT1 pathogenic variants in 46,XY DSD associated with gonadoblastoma

OBJECTIVE

The literature regarding gonadoblastoma risk in exonic Wilms' tumor suppressor gene (WT1) pathogenic variants is sparse. The aim of this study is to describe the phenotypic and genotypic characteristics of Asian-Indian patients with WT1 pathogenic variants and systematically review the literature on association of exonic WT1 pathogenic variants and gonadoblastoma.

DESIGN

Combined retrospective-prospective analysis.

METHODS

In this study, 46,XY DSD patients with WT1 pathogenic variants detected by clinical exome sequencing from a cohort of 150 index patients and their affected relatives were included. The PubMed database was searched for the literature on gonadoblastoma with exonic WT1 pathogenic variants.

RESULTS

The prevalence of WT1 pathogenic variants among 46,XY DSD index patients was 2.7% (4/150). All the four patients had atypical genitalia and cryptorchidism. None of them had Wilms' tumor till the last follow-up, whereas one patient had late-onset nephropathy. 11p13 deletion was present in one patient with aniridia. The family with p.Arg458Gln pathogenic variant had varied phenotypic spectrum of Frasier syndrome; two siblings had gonadoblastoma, one of them had growing teratoma syndrome (first to report with WT1). On literature review, of >100 exonic point pathogenic variants, only eight variants (p.Arg462Trp, p.Tyr177*, p.Arg434His, p.Met410Arg, p.Gln142*, p.Glu437Lys, p.Arg458*, and p.Arg458Gln) in WT1 were associated with gonadoblastoma in a total of 15 cases (including our two cases).

CONCLUSIONS

WT1 alterations account for 3% of 46,XY DSD patients in our cohort. 46,XY DSD patients harboring exonic WT1 pathogenic variants carry a small but definitive risk of gonadoblastoma; hence, these patients require a gonadoblastoma surveillance with a more stringent surveillance in those harboring a gonadoblastoma-associated variant.

Up-to-Date Clinical and Biochemical Workup of the Child and the Adolescent with a Suspected Disorder of Sex Development

BACKGROUND

The suspicion of a disorder of sex development (DSD) often arises at birth, when the newborn presents with ambiguous genitalia, or even during prenatal ultrasound assessments. Less frequently, the aspect of the external genitalia is typically female or male, and the diagnosis of DSD may be delayed until a karyotype is performed for another health issue, or until pubertal age when a girl presents with absence of thelarche and/or menarche or a boy consults for gynaecomastia and/or small testes.

SUMMARY

In this review, we provide a practical, updated approach to clinical and hormonal laboratory workup of the newborn, the child, and the adolescent with a suspected DSD. We focus on how to specifically address the diagnostic approach according to the age and presentation. Key Message: We particularly highlight the importance of a detailed anatomic description of the external and internal genitalia, adequate imaging studies or surgical exploration, the assessment of reproductive hormone levels - especially testosterone, anti-Müllerian hormone, 17-hydroxyprogesterone, and gonadotropins - and karyotyping.

Molecular and Cytogenetic Analysis of Romanian Patients with Differences in Sex Development

Differences in sex development (DSD) are often correlated with a genetic etiology. This study aimed to assess the etiology of DSD patients following a protocol of genetic testing. Materials and methods. This study prospectively investigated a total of 267 patients with DSD who presented to Clinical Emergency Hospital for Children Cluj-Napoca between January 2012 and December 2019. Each patient was clinically, biochemically, and morphologically evaluated. As a first intervention, the genetic test included karyotype + SRY testing. A high value of 17-hydroxyprogesterone was found in 39 patients, in whom strip assay analysis of the CYP21A2 gene was subsequently performed. A total of 35 patients were evaluated by chromosomal microarray technique, and 22 patients were evaluated by the NGS of a gene panel. Results. The karyotype analysis established the diagnosis in 15% of the patients, most of whom presented with sex chromosome abnormalities. Genetic testing of CYP21A2 established a confirmation of the diagnosis in 44% of patients tested. SNP array analysis was particularly useful in patients with syndromic DSD; 20% of patients tested presented with pathogenic CNVs or uniparental disomy. Gene panel sequencing established the diagnosis in 11 of the 22 tested patients (50%), and the androgen receptor gene was most often involved in these patients. The genes that presented as pathogenic or likely pathogenic variants or variants of uncertain significance were RSPO1, FGFR1, WT1, CHD7, AR, NIPBL, AMHR2, AR, EMX2, CYP17A1, NR0B1, GNRHR, GATA4, and ATM genes. Conclusion. An evaluation following a genetic testing protocol that included karyotype and SRY gene testing, CYP21A2 analysis, chromosomal analysis by microarray, and high-throughput sequencing were useful in establishing the diagnosis, with a spectrum of diagnostic yield depending on the technique (between 15 and 50%). Additionally, new genetic variants not previously described in DSD were observed.

The laboratory in the multidisciplinary diagnosis of differences or disorders of sex development (DSD): I) Physiology, classification, approach, and methodologyII) Biochemical and genetic markers in 46,XX DSD

Objectives

The development of female or male sex characteristics occurs during fetal life, when the genetic, gonadal, and internal and external genital sex is determined (female or male). Any discordance among sex determination and differentiation stages results in differences/disorders of sex development (DSD), which are classified based on the sex chromosomes found on the karyotype.

Content

This chapter addresses the physiological mechanisms that determine the development of female or male sex characteristics during fetal life, provides a general classification of DSD, and offers guidance for clinical, biochemical, and genetic diagnosis, which must be established by a multidisciplinary team. Biochemical studies should include general biochemistry, steroid and peptide hormone testing either at baseline or by stimulation testing. The genetic study should start with the determination of the karyotype, followed by a molecular study of the 46,XX or 46,XY karyotypes for the identification of candidate genes.

Summary

46,XX DSD include an abnormal gonadal development (dysgenesis, ovotestes, or testes), an androgen excess (the most frequent) of fetal, fetoplacental, or maternal origin and an abnormal development of the internal genitalia. Biochemical and genetic markers are specific for each group.

Outlook

Diagnosis of DSD requires the involvement of a multidisciplinary team coordinated by a clinician, including a service of biochemistry, clinical, and molecular genetic testing, radiology and imaging, and a service of pathological anatomy.

MAMLD1 and Differences/Disorders of Sex Development: An Update

MAMLD1 (alias CXorf6) was first documented in 2006 as a causative gene of 46,XY differences/disorders of sex development (DSD). MAMLD1/Mamld1 is expressed in the fetal testis and is predicted to enhance the expression of several Leydig cell-specific genes. To date, hemizygous MAMLD1 variants have been identified in multiple 46,XY individuals with hypomasculinized external genitalia. Pathogenic MAMLD1 variants are likely to cause genital abnormalities at birth and are possibly associated with age-dependent deterioration of testicular function. In addition, some MAMLD1 variants have been identified in 46,XX individuals with ovarian dysfunction. However, recent studies have raised the possibility that MAMLD1 variants cause 46,XY DSD and ovarian dysfunction as oligogenic disorders. Unsolved issues regarding MAMLD1 include the association between MAMLD1 variants and 46,XX testicular DSD, gene-gene interactions in the development of MAMLD1-mediated DSD, and intracellular functions of MAMLD1.

The broad phenotypic spectrum of 17α-hydroxylase/17,20-lyase (CYP17A1) deficiency: a case series

CONTEXT

17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in the CYP17A1 gene is a rare form of congenital adrenal hyperplasia typically characterised by cortisol deficiency, mineralocorticoid excess and sex steroid deficiency.

OBJECTIVE

To examine the phenotypic spectrum of 17OHD by clinical and biochemical assessment and corresponding in silico and in vitro functional analysis.

DESIGN

Case series.

PATIENTS AND RESULTS

We assessed eight patients with 17OHD, including four with extreme 17OHD phenotypes: two siblings presented with failure to thrive in early infancy and two with isolated sex steroid deficiency and normal cortisol reserve. Diagnosis was established by mass spectrometry-based urinary steroid profiling and confirmed by genetic CYP17A1 analysis, revealing homozygous and compound heterozygous sequence variants. We found novel (p.Gly111Val, p.Ala398Glu, p.Ile371Thr) and previously described sequence variants (p.Pro409Leu, p.Arg347His, p.Gly436Arg, p.Phe53/54del, p.Tyr60IlefsLys88X). In vitro functional studies employing an overexpression system in HEK293 cells showed that 17,20-lyase activity was invariably decreased while mutant 17α-hydroxylase activity retained up to 14% of WT activity in the two patients with intact cortisol reserve. A ratio of urinary corticosterone over cortisol metabolites reflective of 17α-hydroxylase activity correlated well with clinical phenotype severity.

CONCLUSION

Our findings illustrate the broad phenotypic spectrum of 17OHD. Isolated sex steroid deficiency with normal stimulated cortisol has not been reported before. Attenuation of 17α-hydroxylase activity is readily detected by urinary steroid profiling and predicts phenotype severity.

SIGNIFICANCE STATEMENT

Here we report, supported by careful phenotyping, genotyping and functional analysis, a prismatic case series of patients with congenital adrenal hyperplasia due to 17α-hydroxylase (CYP17A1) deficiency (17OHD). These range in severity from the abolition of function, presenting in early infancy, and unusually mild with isolated sex steroid deficiency but normal ACTH-stimulated cortisol in adult patients. These findings will guide improved diagnostic detection of CYP17A1 deficiency.

A Novel Homozygous Mutation in CYP11A1 Gene is Associated with Severe Adrenal Insufficiency in 46, XX Patient

One of the causes of congenital adrenal insufficiency, a genetically heterogeneous disorder is a mutation in the CYP11A1 gene, which is responsible for the initiation of steriodogenesis by converting cholesterol to pregnenolone. Case: In a now 3 years and 3 months-old girl, adrenal insufficiency was diagnosed in the neonatal period. Clinical exome sequencing for primary adrenal insufficiency revealed a homozygous p.Thr330Met (c.989C>T) variant in the CYP11A1 (NM_000781) gene. Conclusion: Different types of inheritance patterns have been observed in CYP11A1-related adrenal insufficiency cases. We consider our case is an due to an autosomal recessive inheritance.

Oligogenic Causes of Human Differences of Sex Development: Facing the Challenge of Genetic Complexity

BACKGROUND

Deviations of intrauterine sex determination and differentiation and postnatal sex development can result in a very heterogeneous group of differences of sex development (DSD) with a broad spectrum of phenotypes. Variants in genes involved in sexual development cause different types of DSD, but predicting the phenotype from an individual's genotype and vice versa remains challenging.

SUMMARY

Next Generation Sequencing (NGS) studies suggested that oligogenic inheritance contributes to the broad manifestation of DSD phenotypes. This review will focus on possible oligogenic inheritance in DSD identified by NGS studies with a special emphasis on NR5A1variants as an example of oligogenic origin associated with a broad range of DSD phenotypes. We thoroughly searched the literature for evidence regarding oligogenic inheritance in DSD diagnosis with NGS technology and describe the challenges to interpret contribution of these genes to DSD phenotypic variability and pathogenicity. Key Messages: Variants in common DSD genes like androgen receptor (AR), mitogen-activated protein kinase kinase kinase 1 (MAP3K1), Hydroxy-Delta-5-Steroid Dehydrogenase 3 Beta- And Steroid Delta-Isomerase 2 (HSD3B2), GATA Binding Protein 4 (GATA4), zinc finger protein friend of GATA family member 2 (ZFPM2), 17b-hydroxysteroid dehydrogenase type 3 (HSD17B3), mastermind-like domain-containing protein 1 (MAMLD1), and nuclear receptor subfamily 5 group A member 1 (NR5A1) have been detected in combination with additional variants in related genes in DSD patients with a broad range of phenotypes, implying a role of oligogenic inheritance in DSD, while still awaiting proof. Use of NGS approach for genetic diagnosis of DSD patients can reveal more complex genetic traits supporting the concept of oligogenic cause of DSD. However, assessing the pathomechanistic contribution of multiple gene variants on a DSD phenotype remains an unsolved conundrum.

Towards improved genetic diagnosis of human differences of sex development

Despite being collectively among the most frequent congenital developmental conditions worldwide, differences of sex development (DSD) lack recognition and research funding. As a result, what constitutes optimal management remains uncertain. Identification of the individual conditions under the DSD umbrella is challenging and molecular genetic diagnosis is frequently not achieved, which has psychosocial and health-related repercussions for patients and their families. New genomic approaches have the potential to resolve this impasse through better detection of protein-coding variants and ascertainment of under-recognized aetiology, such as mosaic, structural, non-coding or epigenetic variants. Ultimately, it is hoped that better outcomes data, improved understanding of the molecular causes and greater public awareness will bring an end to the stigma often associated with DSD.

AMH and AMHR2 Involvement in Congenital Disorders of Sex Development

Anti-müllerian hormone (AMH) is 1 of the 2 testicular hormones involved in male development of the genitalia during fetal life. When the testes differentiate, AMH is secreted by Sertoli cells and binds to its specific receptor type II (AMHR2) on the müllerian ducts, inducing their regression. In the female fetus, the lack of AMH allows the müllerian ducts to form the fallopian tubes, the uterus, and the upper part of the vagina. The human AMH gene maps to 19p13.3 and consists of 5 exons and 4 introns spanning 2,764 bp. The AMHR2 gene maps to 12q13.13, consists of 11 exons, and is 7,817 bp long. Defects in the AMH pathway are the underlying etiology of a subgroup of disorders of sex development (DSD) in 46,XY patients. The condition is known as the persistent müllerian duct syndrome (PMDS), characterized by the existence of a uterus and fallopian tubes in a boy with normally virilized external genitalia. Approximately 200 cases of patients with PMDS have been reported to date with clinical, biochemical, and molecular genetic characterization. An updated review is provided in this paper. With highly sensitive techniques, AMH and AMHR2 expression has also been detected in other tissues, and massive sequencing technologies have unveiled variants in AMH and AMHR2 genes in hitherto unsuspected conditions.

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 5α-reductase 2 deficiency (n = 26; 17.3%). Most patients presented late in the postpubertal period with primary amenorrhoea in CAIS (89%) and atypical genitalia with gynecomastia in PAIS (71.4%). All CAIS were reared as females and 83.3% of PAIS as males with no gender dysphoria. Four of 6 patients with available testosterone to dihydrotestosterone ratio had a false elevation (>10). Metastatic dysgerminoma was seen in 1 patient in CAIS, while none in the PAIS group had malignancy. Fifteen different (including 6 novel) pathogenic/likely pathogenic variants in AR were found. Nonsense and frameshift variants exclusively led to CAIS phenotype, whereas missense variants led to variable phenotypes. In this largest, monocentric study from the Asian Indian subcontinent, AIS was the second most common cause of 46,XY DSD with similar phenotype but later presentation when compared to cases in the rest of the world. The study reports 6 novel pathogenic variants in AR.

Advances in genomic diagnosis of a large cohort of Egyptian patients with disorders of sex development

Disorders/differences of sex development (DSD) comprise a group of congenital disorders that affect the genitourinary tract and usually involve the endocrine and reproductive system. The aim of this work was to identify genetic variants responsible for disorders of human urogenital development in a cohort of Egyptian patients. This three-year study included 225 patients with various DSD forms, referred to the genetic DSD and endocrinology clinic, National Research Centre, Egypt. The patients underwent thorough clinical examination, hormonal and imaging studies, detailed cytogenetic and fluorescence in situ hybridization analysis, and molecular sequencing of genes known to commonly cause DSD including AR, SRD5A2, 17BHSD3, NR5A1, SRY, and WT1. Whole exome sequencing (WES) was carried out for 18 selected patients. The study revealed a high rate of sex chromosomal DSD (33%) with a wide array of cytogenetic abnormalities. Sanger sequencing identified pathogenic variants in 33.7% of 46,XY patients, while the detection rate of WES reached 66.7%. Our patients showed a different mutational profile compared with that reported in other populations with a predominance of heritable DSD causes. WES identified rare and novel pathogenic variants in NR5A1, WT1, HHAT, CYP19A1, AMH, AMHR2, and FANCA and in the X-linked genes ARX and KDM6A. In addition, digenic inheritance was observed in two of our patients and was suggested to be a cause of the phenotypic variability observed in DSD.

A large cohort of disorders of sex development and their genetic characteristics: 6 novel mutations in known genes

INTRODUCTION

Disorders of sex development (DSD) constitutes a group of congenital conditions that affect urogenital differentiation and are associated with chromosomal, gonadal and phenotypic sex abnormalities.

OBJECTIVE

To evaluate the clinical and genetic features of childhood DSD cases.

MATERIALS AND METHODS

DSD patients followed up between the years of 2002-2018 were evaluated in terms of their complaints, demographic, clinical features and genetic diagnoses.

RESULTS

Out of 289 patients, 143(49.5%) were classified as 46XY DSD, 62(21.5%) as 46XX DSD and 84(29%) as sex chromosomal DSD. Genetic diagnosis was achieved in 150 patients (51.9%). The distribution of the molecular diagnosis of the 46XY DSD patients were; 12 (26.6%) SRD5A2, 10 (22.2%) AR, 7 (15.5%) HSD17B3, 3 (6.6%) WT-1, 2 (4.4%) AMHR2, 2 (4.4%) AMH, 2 (4.4%) LHCGR, 2 (4.4%) HSD3B2, 1 (2.2%) NR5A1, 1 (2.2%) CYP17A1 and 1 (2.2%) SRY mutation. Fifty (80.6%) of the 46XX DSD patients received a diagnosis with clinical and laboratory findings. Twenty-four (38.7%) of them were 21-hydroxylase deficiency, 9(14.5%) Rokitansky-Küster-Hauser Syndrome, 4 (6.5%) 11-β hydroxylase deficiency, 3 (4.8%) gonadal dysgenesis and 2 (3.2%) aromatase deficiency. In 46XX group pathogenic mutations were detected in 21(33.8%) of the patients. Eighty-four (29%) patients were diagnosed as sex chromosomal disorder. Of these 66 (78.5%) were Turner Syndrome, 6 (7.2%) Klinefelter Syndrome and 10 (11.9%) mix gonadal dysgenesis. Gender re-assignment was decided in 11 patients. Malignant and pre-invasive lesions was diagnosed in 8 (2.7%) patients.

CONCLUSION

Many of DSD's are clinically similar and etiology of numerous of them still cannot be established. A multi-disciplinary approach and new rapid genetic diagnostic methods are needed in the process from diagnosis to gender assignment and follow-up.

How Far Should We Explore Hypospadias? Next-generation Sequencing Applied to a Large Cohort of Hypospadiac Patients

BACKGROUND

Next-generation sequencing (NGS) is generally used for patients with severe disorders of sex development (DSD). However, NGS has not been applied extensively for patients with hypospadias only, and most affected children do not benefit from an etiological diagnosis.

OBJECTIVE

To evaluate the clinical usefulness of NGS for patients with hypospadias, regardless of severity.

DESIGN, SETTING, AND PARTICIPANTS

Prospective multicenter research included 293 children with glandular to penoscrotal hypospadias (no undescended testis and no micropenis). After excluding likely pathogenic androgen receptor (AR) variants by Sanger sequencing, an NGS panel tested 336 genes including unexplored candidates in 284 patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The rate of pathogenic and likely pathogenic variants was assessed using REVEL, ClinVar, and in-house tools (Captain-ACHAB, MobiCNV, and MobiDetails).

RESULTS AND LIMITATIONS

Likely pathogenic variants were identified in 16 (5.5%) patients with both Sanger sequencing and NGS taken into account. Some genes were related to DSD (AR, NR5A1, HSD17B3, and MAMLD1), but reverse phenotyping revealed two syndromic disorders with midline defects (MID1) and alteration in the retinoic acid signaling pathway (RARA). Coverage analysis revealed an 18q deletion. Identification of likely pathogenic variants increased with hypospadias severity. Other variants of unknown significance (VUSs) in genes implicated in hypogonadotropic hypogonadism, Noonan syndrome, and genital tubercle development were also identified. Genetic study mainly focused on exonic variants, and most cases remain unexplained.

CONCLUSIONS

NGS reveals minor forms of DSD, undiagnosed syndromes, or candidate rare variants in new genes, indicating that even patients with mild hypospadias benefit from advanced sequencing techniques. Early molecular diagnosis would help improve follow-up at puberty and medical counseling for initially undiagnosed syndromes. Future studies will improve the diagnosis by investigating the contribution of VUSs.

PATIENT SUMMARY

Next-generation sequencing enables simultaneous testing of numerous genes and should not be limited to disorders of sex development cases. Even patients with mild hypospadias would benefit from early diagnosis of a genetic defect implicated in sex development or other syndromes.

Performance of mutation pathogenicity prediction tools on missense variants associated with 46,XY differences of sex development

OBJECTIVES

Single nucleotide variants (SNVs) are the most common type of genetic variation among humans. High-throughput sequencing methods have recently characterized millions of SNVs in several thousand individuals from various populations, most of which are benign polymorphisms. Identifying rare disease-causing SNVs remains challenging, and often requires functional in vitro studies. Prioritizing the most likely pathogenic SNVs is of utmost importance, and several computational methods have been developed for this purpose. However, these methods are based on different assumptions, and often produce discordant results. The aim of the present study was to evaluate the performance of 11 widely used pathogenicity prediction tools, which are freely available for identifying known pathogenic SNVs: Fathmn, Mutation Assessor, Protein Analysis Through Evolutionary Relationships (Phanter), Sorting Intolerant From Tolerant (SIFT), Mutation Taster, Polymorphism Phenotyping v2 (Polyphen-2), Align Grantham Variation Grantham Deviation (Align-GVGD), CAAD, Provean, SNPs&GO, and MutPred.

METHODS

We analyzed 40 functionally proven pathogenic SNVs in four different genes associated with differences in sex development (DSD): 17β-hydroxysteroid dehydrogenase 3 (HSD17B3), steroidogenic factor 1 (NR5A1), androgen receptor (AR), and luteinizing hormone/chorionic gonadotropin receptor (LHCGR). To evaluate the false discovery rate of each tool, we analyzed 36 frequent (MAF>0.01) benign SNVs found in the same four DSD genes. The quality of the predictions was analyzed using six parameters: accuracy, precision, negative predictive value (NPV), sensitivity, specificity, and Matthews correlation coefficient (MCC). Overall performance was assessed using a receiver operating characteristic (ROC) curve.

RESULTS

Our study found that none of the tools were 100% precise in identifying pathogenic SNVs. The highest specificity, precision, and accuracy were observed for Mutation Assessor, MutPred, SNP, and GO. They also presented the best statistical results based on the ROC curve statistical analysis. Of the 11 tools evaluated, 6 (Mutation Assessor, Phanter, SIFT, Mutation Taster, Polyphen-2, and CAAD) exhibited sensitivity >0.90, but they exhibited lower specificity (0.42-0.67). Performance, based on MCC, ranged from poor (Fathmn=0.04) to reasonably good (MutPred=0.66).

CONCLUSION

Computational algorithms are important tools for SNV analysis, but their correlation with functional studies not consistent. In the present analysis, the best performing tools (based on accuracy, precision, and specificity) were Mutation Assessor, MutPred, and SNPs&GO, which presented the best concordance with functional studies.

Disorders of sexual development with XY karyotype and female phenotype: clinical findings and genetic background in a cohort from a single centre

PURPOSE

46, XY disorders (or differences) of sex development (DSD) are a group of clinical conditions with variable genetic background; correct diagnosis is often difficult, but it permits to optimize the management. The aim of this study is to identify clinical and genetics features of a group of women with 46, XY DSD to define some issues characterizing people with 46, XY DSD in Italy.

METHODS

Retrospective analysis of girls and women with 46, XY DSD and female phenotype evaluated between year 2000 and 2016, performed by anonymised database, focusing on the clinical features and management, including presentation, first diagnostic suspect, gonadal surgery and molecular diagnostic delay.

RESULTS

A total of 84 records were collected (mean age at clinical presentation: 9.1 ± 7.9 years; mean age at definitive diagnosis: 20.1 ± 15.0 years). Complete androgen insensitivity syndrome was the most common diagnosis (60%). Only 12 patients (14.3%) did not receive a molecular diagnosis. Early misdiagnoses frequently occurred; diagnostic delay was 10.2 ± 11.2 years, being reduced in patients presenting from 2007 to 2016. The discordance between genotypic and phenotypic sex during pregnancy or at birth determined early reason for referral in a considerable percentage (4.9%).

CONCLUSION

Misdiagnosis and long diagnostic delays are present in females with 46, XY DSD in Italy, but the new genetic techniques permit faster right diagnoses in the last years. The centralization in dedicated third level units permits to reduce the number of patients without a molecular diagnosis, allowing better clinical management and appropriate genetic counselling.

Prevalence of gene mutations in a Chinese 46,XY disorders of sex development cohort detected by targeted next-generation sequencing

46,XY disorders of sex development (DSD) is characterized by incomplete masculinization genitalia, with gonadal dysplasia and with/without the presence of Müllerian structures. At least 30 genes related to 46,XY DSD have been found. However, the clinical phenotypes of patients with different gene mutations overlap, and accurate diagnosis relies on gene sequencing technology. Therefore, this study aims to determine the prevalence of pathogenic mutations in a Chinese cohort with 46,XY DSD by the targeted next-generation sequencing (NGS) technology. Eighty-seven 46,XY DSD patients were enrolled from the Peking Union Medical College Hospital (Beijing, China). A total of fifty-four rare variants were identified in 60 patients with 46,XY DSD. The incidence of these rare variants was approximately 69.0% (60/87). Twenty-five novel variants and 29 reported variants were identified. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, thirty-three variants were classified as pathogenic or likely pathogenic variants and 21 variants were assessed as variants of uncertain significance. The overall diagnostic rate was about 42.5% based on the pathogenic and likely pathogenic variants. Androgen receptor (AR), steroid 5-alpha-reductase 2 (SRD5A2) and nuclear receptor subfamily 5 Group A member 1 (NR5A1) gene variants were identified in 21, 13 and 13 patients, respectively. The incidence of these three gene variants was about 78.3% (47/60) in patients with rare variants. It is concluded that targeted NGS is an effective method to detect pathogenic mutations in 46,XY DSD patients and AR, SRD5A2, and NR5A1 genes were the most common pathogenic genes in our cohort.