Lack of causative mutation in the AMH and AMHR2 genes in a cat (38,XY) with persistent Mullerian duct syndrome (PMDS).

A 1-year-old European shorthair male cat with a normally developed penis was subjected to genetic, endocrinological and histological studies due to unilateral cryptorchidism. The blood testosterone level was typical for males, while the level of anti-Mullerian hormone (AMH) was very low. Surgical removal of internal reproductive organs was followed by a histological study, which revealed inactive testicles with neoplastic changes and derivatives of Mullerian ducts. Cytogenetic analysis showed a normal XY sex chromosome complement and molecular analysis confirmed the presence of Y-linked genes (SRY and ZFY). Although the level of AMH was low, two normal copies of the AMH gene were found using droplet digital PCR (ddPCR). Analysis of the coding sequences of two candidate genes (AMH and AMHR2) for persistent Mullerian duct syndrome (PMDS) in the affected cat and in control male cats (n = 24) was performed using the Sanger sequencing method. In the affected cat, homozygosity was found for three novel missense variants in Exon 1 (one SNP) and Exon 5 (two SNPs) of AMH, but the same homozygous genotypes were also observed in one and two control cats, respectively, whose sex development was not examined. Three known synonymous variants with homozygous status were found in AMHR2. We conclude that the DNA variants identified in AMH and AMHR2 are not responsible for PMDS in the affected cat.

Diagnostic and therapeutic challenges with germ cell tumours associated with transverse testicular ectopia and persistent Müllerian duct syndrome.

Transverse testicular ectopia (TTE) is an infrequent ectopic testis where both testes descend via the same inguinal canal, located in the same hemiscrotum, and augments the risk of developing testicular tumours. Type II TTE is accompanied by persistent Müllerian duct syndrome, where the Müllerian structures persist for various reasons. Here, we present a case of an adult in his early 30s, who presented with a right testicular swelling and was diagnosed as type II TTE and testicular mixed germ cell tumour after surgery. We could find only 13 similar cases of TTE and testicular tumours in the literature. Our case highlights the importance of clinical acumen with detailed history, meticulous clinical examination, radiological investigations and a detailed pathological examination while dealing with such sporadic presentations.

Identification and functional analysis of a rare variant of gene DHX37 in a patient with 46,XY disorders of sex development.

BACKGROUND: 46,XY sex reversal 11 (SRXY11) [OMIM#273250] is characterized by genital ambiguity that may range from mild male genital defects to gonadal sex reversal in severe cases. DHX37 is an RNA helicase that has recently been reported as a cause of SRXY11. So far, a total of 21 variants in DHX37 have been reported in 58 cases with 46,XY disorders of sex development (DSD). METHODS: Whole exome sequencing (WES) was conducted to screen for variations in patients with 46,XY DSD. The subcellular localization of mutant DHX37 proteins was detected by immunofluorescence. And the levels of mutant DHX37 proteins were detected via Western blotting. RESULTS: A novel pathogenic variant of DHX37 was identified in a patient with 46,XY DSD c.2012G > C (p.Arg671Thr). Bioinformatics analysis showed that the protein function of the variant was impaired. Compared with the structure of the wild-type DHX37 protein, the number of hydrogen bonds and interacting amino acids of the variant protein were changed to varying degrees. In vitro assays revealed that the variant had no significant effect on the intracellular localization of the protein but significantly reduced the expression level of the protein. CONCLUSIONS: Our finding further expands the spectrum of the DHX37 variant and could assist in the molecular diagnosis of 46,XY DSD patients.

Identification of a novel homozygous NR5A1 variant in a patient with a 46,XY disorders of sex development.

OBJECTIVES: Nuclear receptor subfamily 5 group A member 1 (NR5A1) is a transcription factor critical for the development of various organs. Pathogenic variants in NR5A1 are associated with a spectrum of disorders of sex development (DSD). CASE PRESENTATION: A 15-month-old baby, raised as a girl, was referred for genital swelling and ambiguous genitalia. Born to healthy consanguineous parents, the baby had a phallus, perineal hypospadias, labial fusion, and a hypoplastic scrotum. Hormonal evaluation showed normal levels, and ultrasonography revealed small gonads and absence of Müllerian derivatives. Post-human chorionic gonadotropin (hCG) testing indicated an adequate testosterone response. The karyotype was 46,XY, and in it was found a homozygous NR5A1 variant (c.307 C>T, p.Arg103Trp) in a custom 46 XY DSD gene panel. Notably, the patient exhibited complete sex reversal, hyposplenia, and no adrenal insufficiency. CONCLUSIONS: Previously, NR5A1 pathogenic variants were considered to be dominantly inherited, and homozygous cases were thought to be associated with adrenal insufficiency. Despite the homozygous pathogenic variant, our patient showed hyposplenism with normal adrenal function; this highlights the complexity of NR5A1 genotype-phenotype correlations. These patients should be monitored for adrenal insufficiency and DSD as well as splenic function.

Spectrum of Genital and Extragenital Anomalies in Malformation Syndromes Associated With 46, XY Disorders of Sex Development: A Single Center Experience.

OBJECTIVES: This study aimed at integrating the clinical and phenotypic characteristics, hormonal profile and genetic diagnosis of children with malformation syndromes associated with XY disorders of sex development (DSD) in a single-center in Egypt. METHODS: This retrospective study included patients with syndromic XY DSD recruited from the Pediatric Endocrinology and Surgery units at Alexandria University Children's Hospital (AUCH), Alexandria, Egypt, between 2018 and 2023. All patients included in the study underwent a detailed clinical and laboratory evaluation, ultrasonography (and laparoscopy if needed). RESULTS: The study included 30 children with syndromic XY DSD; most of these children were diagnosed at birth. The most common extragenital malformations included skeletal anomalies (70%), facial dysmorphism (46.7%), cerebral malformations (30%) and congenital heart disease (23.3%). Ventricular septal defect was the most common congenital heart disease. CONCLUSION: Integration between clinical, laboratory and genetic data is the cornerstone in the management of XY DSD patients for appropriate decision making of surgical intervention and sex assignment, in addition to screening for other associated features of each mutation.

Expanding the phenotypic spectrum of LHCGR signal peptide insertion variant: novel clinical and allelic findings causing Leydig cell hypoplasia type II.

PURPOSE: Leydig cell hypoplasia (LCH) type II is a rare disease with only a few cases reported. Patients presented with hypospadias, micropenis, undescended testes, or infertility. In this study, we report a new patient with compound heterozygous variants in the LHCGR gene and LCH type II phenotype. METHODS: Whole exome sequencing (WES) was performed followed by Sanger sequencing to confirm the detected variants in the patient and his parents. RESULTS: A novel missense variant (p.Phe444Cys) was identified in a highly conserved site and is verified to be in trans with the signal peptide's 33-bases insertion variant. CONCLUSION: Our research provides a more comprehensive clinical and genetic spectrum of Leydig cell hypoplasia type II. It highlighted the importance of WES in the diagnosis of this uncommon genetic disorder as well as the expansion of the genotype of LCH type II.

[Value of the human chorionic gonadotropin stimulation test in the diagnosis of disorder of sexual development in children]. / äººç»’æ¯›è†œä¿ƒæ€§è ºæ¿€ç´ æ¿€å‘è¯•éªŒåœ¨æ€§å‘è‚²å¼‚å¸¸å„¿ç«¥ä¸­çš„è¯Šæ–­ä½œç”¨è¯„ä¼°.

OBJECTIVES: To investigate the value of the human chorionic gonadotropin (hCG) stimulation test in the diagnosis of disorder of sexual development (DSD) in children. METHODS: A retrospective analysis was conducted on 132 children with DSD. According to the karyotype, they were divided into three groups: 46,XX group (n=10), 46,XY group (n=87), and sex chromosome abnormality group (n=35). The above groups were compared in terms of sex hormone levels before and after hCG stimulation test, and the morphological manifestation of the impact of testicular tissue on the results of the hCG stimulation test was analyzed. RESULTS: There was no significant difference in the multiple increase of testosterone after stimulation among the three groups (P>0.05). In the 46,XY group, the children with 5α-reductase type 2 deficiency had a testosterone-to-dihydrotestosterone ratio higher than that of the 46,XY DSD children with other causes. Morphological analysis showed that DSD children with testicular tissue demonstrated a significantly higher multiple increase in testosterone after stimulation compared to children without testicular tissue (P<0.05). CONCLUSIONS: The hCG stimulation test has an important value in assessing the presence and function of testicular interstitial cells in children with different types of DSD, and it is recommended to perform the hCG stimulation test for DSD children with unclear gonadal type.

Steroidogenic acute regulatory protein (STAR) deficiency: Our experience and systematic review for phenotype-genotype correlation.

OBJECTIVE: Lipoid congenital adrenal hyperplasia (LCAH) is caused by mutations in STAR. A systematic review of phenotype-genotype correlation and data on testicular histology in LCAH patients is unavailable. We aim to describe our experience and provide phenotype-genotype correlation. DESIGN, PATIENTS AND MEASUREMENTS: Retrospective review of three genetically proven LCAH patients from our centre and per-patient data analysis from a systematic review of 292 probands. The phenotypic subgroups of 46,XY were Group A (typical female genitalia), Group B (atypical genitalia) and Group C (typical male genitalia). RESULTS: We report three new LCAH probands from India, all diagnosed post-infancy with preserved gonadal function and one novel variant. The systematic review reports 46,XY to 46,XX LCAH ratio of 1.1 (155:140). Patients with 46,XY LCAH in Group A were diagnosed in infancy (116/117) and had higher mineralocorticoid involvement than Group C (96.4% vs. 75%, p = 0.035), whereas Group C had preserved gonadal function. Hyperplastic adrenals are noted in ~60% of LCAH diagnosed with primary adrenal insufficiency in infancy. There was no report of gonadal germ cell cancer and rare reports of germ cell neoplasia in situ in adolescents, especially with intraabdominal gonads. Two-thirds of LCAH probands were East-Asian and 11/16 regional recurrent variants were from East Asia. There was minimal overlap between variants in Groups A (n = 55), B (n = 9) and C (n = 8). All nonsense and frameshift and most of the splice-site variants and deletion/insertions were present in Group A. CONCLUSIONS: We report three new cases of LCAH from India. We propose a phenotype-derived genotypic classification of reported STAR variants in 46,XY LCAH.

[Analysis of a child with 46,XY Disorder of sex development due to a novel variant of NR5A1 gene].

OBJECTIVE: To analyze the clinical features and genetic basis of a child with Disorder of sex development (DSD). METHODS: A child who was admitted to the Linyi People's Hospital for primary amenorrhoea on July 29, 2019 was selected as the study subject. Clinical data of the child was collected. Chromosomal karyotyping and quantitative real-time PCR were used to detect Y chromosome microdeletions and other chromosomal aberrations. Next-generation sequencing was carried out for the child and her parents. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 13-year-old girl, has featured primary amenorrhoea and onset of secondary sex characteristics of males. Ultrasound exam had detected no uterus and definite ovarian structure, but narrow band vaginal hypoecho and curved cavernoid structure. The child was found to have a 46,XY karyotype without an AZF deletion. DNA sequencing revealed that she has harbored a maternally derived c.323delA (p.Q108Rfs*188) variant in the nuclear receptor subfamily 5 group A member 1 (NR5A1) gene, which may result in a truncated protein. The variant was classified as pathogenic (PVS1+PM2_Supporting+PP4) based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION: The NR5A1: c.323delA variant probably underlay the pathogenesis of 46,XY DSD in this child. The discovery of the novel variant has enriched the mutational spectrum of the NR5A1 gene and provided a basis for clinical diagnosis, treatment and prenatal diagnosis.

The genetic spectrum of a Chinese series of patients with 46, XY disorders of the sex development.

PURPOSE: The etiology of 46, XY disorders of sex development (46, XY DSD) is complex, and studies have shown that different series of patients with 46, XY DSD has different genetic spectrum. In this study, we aimed to investigate the underlying genetic etiology in a Chinese series of patients with 46, XY DSD by whole exome sequencing (WES). METHODS: Seventy patients with 46, XY DSD were enrolled from the Peking Union Medical College Hospital (Beijing, China). The detailed clinical characteristics were evaluated, and peripheral blood was collected for WES to find the patients' rare variants (RVs) of genes related to 46, XY DSD. The clinical significance of the RVs was annotated according to American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS: A total of 57 RVs from nine genes were identified in 56 patients with 46, XY DSD, which include 21 novel RVs and 36 recurrent RVs. Based on the American ACMG guidelines, 43 variants were classified as pathogenic(P) or likely pathogenic (LP) variants and 14 variants were defined as variants of uncertain significance (VUS). P or LP variants were identified in 64.3% (45/70) patients of the series. Thirty-nine, 14, and 4 RVs were involved in the process of androgen synthesis and action, testicular determination and developmental process, and syndromic 46, XY DSD, respectively. The top three genes most frequently affected to cause 46, XY DSD were AR, SRD5A2, and NR5A1. Seven patients were found harboring RVs of the 46, XY DSD pathogenic genes identified in recent years, namely DHX37 in four patients, MYRF in two patients, and PPP2R3C in one patient. CONCLUSION: We identified 21 novel RVs of nine genes, which extended the genetic spectrum of 46, XY DSD pathogenic variants. Our study showed that 60% of the patients were caused by AR, SRD5A2 or NR5A1 P/LP variants. Therefore, polymerase chain reaction (PCR) amplification and Sanger sequencing of these three genes could be performed first to identify the pathogeny of the patients. For those patients whose pathogenic variants had not been found, whole-exome sequencing could be helpful in determining the etiology.

Long-read genome sequencing reveals a novel intronic retroelement insertion in NR5A1 associated with 46,XY differences of sexual development.

Despite significant advancements in rare genetic disease diagnostics, many patients with rare genetic disease remain without a molecular diagnosis. Novel tools and methods are needed to improve the detection of disease-associated variants and understand the genetic basis of many rare diseases. Long-read genome sequencing provides improved sequencing in highly repetitive, homologous, and low-complexity regions, and improved assessment of structural variation and complex genomic rearrangements compared to short-read genome sequencing. As such, it is a promising method to explore overlooked genetic variants in rare diseases with a high suspicion of a genetic basis. We therefore applied PacBio HiFi sequencing in a large multi-generational family presenting with autosomal dominant 46,XY differences of sexual development (DSD), for whom extensive molecular testing over multiple decades had failed to identify a molecular diagnosis. This revealed a rare SINE-VNTR-Alu retroelement insertion in intron 4 of NR5A1, a gene in which loss-of-function variants are an established cause of 46,XY DSD. The insertion segregated among affected family members and was associated with loss-of-expression of alleles in cis, demonstrating a functional impact on NR5A1. This case highlights the power of long-read genome sequencing to detect genomic variants that have previously been intractable to detection by standard short-read genomic testing.

Persistent Müllerian Duct Syndrome Diagnosed Incidentally: A Case Report.

Persistent Müllerian Duct syndrome is a rare male disorder of sexual development. The phenotypically and genotypically male patient presents with female internal organs (i.e., uterus, cervix, fallopian tubes and upper part of vagina) due to deficiency of anti-mullerian hormone or insensitivity of tissues to Anti Mullerian Hormone. We present a 19 year old male who came with complaint of right iliac fossa pain. He was investigated for acute appendicitis and on imaging, he was diagnosed to have bilateral cryptorchidism with rudimentary uterus. Computed tomography followed by pelvic ultrasonography was done which indicated two testes in abdomen and a soft tissue density structure, identified as a rudimentary uterus located posterior to the urinary bladder. CT scan findings were further confirmed by magnetic resonance imaging pelvis. A trial of stepwise orchidopexy followed by orchidectomy with removal of rudimentary uterus was performed laparoscopically. Additionally, he was counselled for long term sex hormone replacement and reproductive failure in future.

DMRT1 is a testis-determining gene in rabbits and is also essential for female fertility.

DMRT1 is the testis-determining factor in several species of vertebrates, but its involvement in mammalian testes differentiation, where SRY is the testis-determining gene, remains ambiguous. So far, DMRT1 loss-of-function has been described in two mammalian species and induces different phenotypes: Disorders of Sex Development (46, XY DSD) in men and male infertility in mice. We thus abolished DMRT1 expression by CRISPR/Cas9 in a third species of mammal, the rabbit. First, we observed that gonads from XY DMRT1-/- rabbit fetuses differentiated like ovaries, highlighting that DMRT1 is involved in testis determination. In addition to SRY, DMRT1 is required in the supporting cells to increase the expression of the SOX9 gene, which heads the testicular genetic cascade. Second, we highlighted another function of DMRT1 in the germline since XX and XY DMRT1-/- ovaries did not undergo meiosis and folliculogenesis. XX DMRT1-/- adult females were sterile, showing that DMRT1 is also crucial for female fertility. To conclude, these phenotypes indicate an evolutionary continuum between non-mammalian vertebrates such as birds and non-rodent mammals. Furthermore, our data support the potential involvement of DMRT1 mutations in different human pathologies, such as 46, XY DSD as well as male and female infertility.

Animals that reproduce sexually have organs called gonads, the ovaries and testes, which produce eggs and sperm. These organs, which are different in males and females, originate from the same cells during the development of the embryo. As a general rule, the chromosomal sex of an embryo, which gets determined at fertilization, leads to the activation and repression of specific genes. This in turn, controls whether the cells that will form the gonads will differentiate to develop testes or ovaries. Disruption of the key genes involved in the differentiation of the gonads can lead to fertility problems, and in some cases, it can cause the gonads to develop in the 'opposite' direction, resulting in a sex reversal. Identifying these genes is therefore essential to know how to maintain or restore fertility. DMRT1 is a gene that drives the differentiation of gonadal cells into the testicular pathway in several species of animals with backbones, including species of fish, frogs and birds. However, its role in mammals ­ where testis differentiation is driven by a different gene called SRY ­ is not well understood. Indeed, when DMRT1 is disrupted in male humans it leads to disorders of sex development, while disrupting this gene in male mice causes infertility. To obtain more information about the roles of DMRT1 in mammalian species, Dujardin et al. disrupted the gene in a third species of mammal: the rabbit. Dujardin et al. observed that chromosomally-male rabbits lacking DMRT1 developed ovaries instead of testes, showing that in rabbits, both SRY and DMRT1 are both required to produce testes. Additionally, this effect is similar to what is seen in humans, suggesting that rabbits may be a better model for human gonadal differentiation than mice are. Additionally, Dujardin et al. were also able to show that in female rabbits, lack of DMRT1 led to infertility, an effect that had not been previously described in other species. The results of Dujardin et al. may lead to better models for gonadal development in humans, involving DMRT1 in the differentiation of testes. Interestingly, they also suggest the possibility that mutations in this gene may be responsible for some cases of infertility in women. Overall, these findings indicate that DMRT1 is a key fertility gene.

Male pseudohermaphroditism in a complex malformed calf born with an acardius amorphus cotwin-a case report.

BACKGROUND: Male pseudohermaphroditism is a developmental anomaly wherein animals are genetically and gonadally male, but their internal and/or external genitalia resemble those of females. In cattle, pseudohermaphroditism is often accompanied by multiple severe malformations. To the best of our knowledge, this is the first report of male pseudohermaphroditism in a complex malformed calf born with an acardius amorphous cotwin. CASE PRESENTATION: This report describes the case of a three-day-old, male anurous Japanese Black calf born with an acardius amorphous cotwin, complete absence of the tail, agenesis of the anus, separate scrota, and umbilical hernia. Transthoracic echocardiography and computed tomography revealed serious malformations in the skeletal system and the circulatory, digestive, urinary, and genital organs. Necropsy revealed rectal atresia, immature testes, epididymis, and penis, but no male accessory gonads. Histological analyses revealed vaginal- and uterine-like tissues adjacent to or fused to the rectum. Fluorescence in situ hybridization detected X and Y chromosomes, and some cells presented two X-probe signals in the same nucleus. CONCLUSIONS: In contrast to the male genitalia, the female genitalia derived from the Müllerian ducts were difficult to detect by necropsy in the presented case. Many similar cases may be overlooked in clinical practice.

Induced pluripotent stem cell line generated from a patient with differences in sex development (DSD) and multiple genetic variants including a large deletion in NR5A1.

The nuclear receptor subfamily 5, Group A, Member 1 (NR5A1) gene encodes steroidogenic factor 1 (SF1), which is necessary for development of steroid hormone-producing tissues including the gonad and adrenal gland. An induced pluripotent stem cell line (iPSC) LCHi002-B was generated from a participant with differences (disorders) of sex development (DSD) and multiple genetic variants including a large deletion in NR5A1, and three single nucleotide changes in DYNC2H1, PDE4D, and ZFPM2. The line presented typical morphology, expressed stem cell markers, differentiated into three germ layers, had normal karyotype, was mycoplasma-free, and carried mutations in NR5A1, DYNC2H1, PDE4D, and ZFPM2.

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

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

Genetic control of typical and atypical sex development.

Sex development relies on the sex-specific action of gene networks to differentiate the bipotential gonads of the growing fetus into testis or ovaries, followed by the differentiation of internal and external genitalia depending on the presence or absence of hormones. Differences in sex development (DSD) arise from congenital alterations during any of these processes, and are classified depending on sex chromosomal constitution as sex chromosome DSD, 46,XY DSD or 46,XX DSD. Understanding the genetics and embryology of typical and atypical sex development is essential for diagnosing, treating and managing DSD. Advances have been made in understanding the genetic causes of DSD over the past 10 years, especially for 46,XY DSD. Additional information is required to better understand ovarian and female development and to identify further genetic causes of 46,XX DSD, besides congenital adrenal hyperplasia. Ongoing research is focused on the discovery of further genes related to typical and atypical sex development and, therefore, on improving diagnosis of DSD.