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

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

Urogenital anomalies and urinary incontinence in an English Cocker Spaniel dog with XX sex reversal.

A 3-year-old dog weighing 8 kg was referred with a disorder of sexual development and persistent urinary incontinence before and after gonadohysterectomy performed at a local animal hospital. Histopathological examination disclosed hypoplasia of the testes, epididymis, pampiniform plexus, and uterus. On ultrasonography, an anomalous structure containing anechoic fluid was identified in the region dorsal to the urinary bladder. An anomalous communication between the proximal urethra and the remnant uterus and vagina was found on retrograde urethrography under fluoroscopy. Reflux of contrast medium into the anomalous structure, suspected to be the uterus and cranial vagina, from the urethra was detected. Computed tomography identified the anomalous structure between the rectum and urethra. The anomalous structure was removed via laparotomy and the urinary incontinence resolved. The diagnosis of XX sex reversal with a developmental anomaly of the genitourinary tract was made on the basis of laparotomy findings and cytogenetic and SRY gene analyses.

Female-to-male sex reversal associated with unique Xp21.2 deletion disrupting genomic regulatory architecture of the dosage-sensitive sex reversal region.

BACKGROUND: The XX male disorder of sex development (DSD) is a rare condition that is most commonly associated with the presence of the SRY gene on one of the X chromosomes due to unequal crossing-over between sex chromosomes during spermatogenesis. However, in about 20% of the XX male individuals, SRY is missing, although these persons have at least some testis differentiation. The genetic basis of genital ambiguity and the mechanisms triggering testis development in such patients remain unknown. METHODS: The proband with 46,XX SRY-negative testicular DSD was screened for point mutations by whole exome sequencing and CNVs using a high-resolution DSD gene-targeted and whole genome array comparative genomic hybridisation. The identified Xp21.2 genomic alteration was further characterised by direct sequencing of the breakpoint junctions and bioinformatics analysis. RESULTS: A unique, 80 kb microdeletion removing the regulatory sequences and the NR0B1 gene was detected by microarray analysis. This deletion disturbs the human-specific genomic architecture of the Xp21.2 dosage-sensitive sex (DSS) reversal region in the XX patient with male-appearing ambiguous genitalia and ovotestis. CONCLUSIONS: Duplication of the DSS region containing the MAGEB and NR0B1 genes has been implicated in testis repression and sex reversal. Identification of this microdeletion highlights the importance of genomic integrity in the regulation and interaction of sex determining genes during gonadal development.

[Analysis of clinical features and related genes variation in five patients with 46, XX male syndrome].

Objective: To explore the clinical manifestations and molecular features of 46, XX male syndrome. Method: The clinical and molecular data of five 46, XX male syndrome cases treated in the Department of Pediatrics of Shanghai Ruijin Hospital form August 2010 to August 2014 were retrospectively analyzed. Result: The five patients were all sociopsychologically males and came to hospital respectively for short stature, ambiguous genitalia or gynecomastia. They were all below the normal male's average height, and their karyotype was all 46, XX. One case in five was verified as sex determining region of Y chromosome (SRY gene) positive revealed no abnormality in their external genitalia. He had short stature since childhood, whose SRY gene fragments were shown by FISH transferred to the ends of X chromosome. Three cases in four were SRY gene negative with ambiguous genitalia of cryptorchidism and testicular dysplasia to different degrees. The copy number variations of SOX9 gene was found in one case, the loss of heterozygosity area in DHH gene of one case. Another SRY gene negative patient who had normal male external genitalia, came to the hospital due to puberty gynecomastia, that of SOX9 gene and its upstream gene both increased. Conclusion: The main clinical characteristics of 46, XX male syndrome are male phenotype, 46, XX karyotype, gonad of testis or ovotestis and no uterus. In addition, short stature, ambiguous genitalia or gynecomastia can be one reason for hospital visits. SRY gene translocation, SOX9 gene and its upstream gene copy number increase all can lead to 46, XX male syndrome. The cause of some may play an important role in 46, XX male syndrome, but has not yet been determined.

A duplication upstream of SOX9 was not positively correlated with the SRY­negative 46,XX testicular disorder of sex development: A case report and literature review.

The 46,XX male disorder of sex development (DSD) is rarely observed in humans. Patients with DSD are all male with testicular tissue differentiation. The mechanism of sex determination and differentiation remains to be elucidated. In the present case report, an 46,XX inv (9) infertile male negative for the sex­determining region of the Y chromosome (SRY) gene was examined. This infertile male was systemically assessed by semen analysis, serum hormone testing and gonadal biopsy. Formalin­fixed and paraffin­embedded gonad tissues were assessed histochemically. The SRY gene was analyzed by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). The other 23 specific loci, including the azoospermia factor region on the Y chromosome and the sequence-targeted sites of the SRY­box 9 (SOX9) gene were analyzed by PCR. The genes RSPO1, DAX1, SOX3, ROCK, DMRT1, SPRY2 and FGF9 were also assessed using sequencing analysis. Affymetrix Cytogenetics Whole Genome 2.7 M Arrays were used for detecting the genomic DNA from the patient and the parents. The patient with the 46,XX inv (9) (p11q13) karyotype exhibited male primary, however, not secondary sexual characteristics. However, the patient's mother with the 46, XX inv (9) karyotype was unaffected. The testicular tissue dysplasia of the patient was confirmed by tissue biopsy and absence of the SRY gene, and the other 23 loci on the Y chromosome were confirmed by FISH and/or PCR. The RSPO1, DAX1, SOX3, ROCK, DMRT1, SPRY2 and FGF9 genes were sequenced and no mutations were detected. A duplication on the 3 M site in the upstream region of SOX9 was identified in the patient as well as in the mother. The patient with the 46,XX testicular DSD and SRY­negative status was found to be infertile. The duplication on the 3 M site in the upstream region of SOX9 was a polymorphism, which indicated that the change was not a cause of 46,XX male SDS. These clinical, molecular and cytogenetic findings suggested that other unidentified genetic or environmental factors are significant in the regulation of SDS.

46,XX testicular disorder of sexual development with SRY-negative caused by some unidentified mechanisms: a case report and review of the literature.

BACKGROUND: 46,XX testicular disorder of sex development is a rare genetic syndrome, characterized by a complete or partial mismatch between genetic sex and phenotypic sex, which results in infertility because of the absence of the azoospermia factor region in the long arm of Y chromosome. CASE PRESENTATION: We report a case of a 14-year-old male with microorchidism and mild bilateral gynecomastia who referred to our hospital because of abnormal gender characteristics. The patient was treated for congenital scrotal type hypospadias at the age of 4 years. Semen analysis indicated azoospermia by centrifugation of ejaculate. Levels of follicle-stimulating hormone and luteinizing hormone were elevated, while that of testosterone was low and those of estradiol and prolactin were normal. The results of gonadal biopsy showed hyalinization of the seminiferous tubules, but there was no evidence of spermatogenic cells. Karyotype analysis of the patient confirmed 46,XX karyotype and fluorescent in situ hybridization analysis of the sex-determining region Y (SRY) gene was negative. Molecular analysis revealed that the SRY gene and the AZFa, AZFb and AZFc regions were absent. No mutation was detected in the coding region and exon/intron boundaries of the RSPO1, DAX1, SOX9, SOX3, SOX10, ROCK1, and DMRT genes, and no copy number variation in the whole genome sequence was found. CONCLUSION: This study adds a new case of SRY-negative 46,XX testicular disorder of sex development and further verifies the view that the absence of major regions from the Y chromosome leads to an incomplete masculine phenotype, abnormal hormone levels and infertility. To date, the mechanisms for induction of testicular tissue in 46,XX SRY-negative patients remain unknown, although other genetic or environmental factors play a significant role in the regulation of sex determination and differentiation.

Investigation of mutations in the SRY, SOX9, and DAX1 genes in sex reversal patients from the Sichuan region of China.

We investigated the molecular genetic mechanism of sex reversal by exploring the relationship between mutations in the sex-determining genes SRY, SOX9, and DAX1 with genetic sex reversal disease. Mutations in the three key genes were detected by polymerase chain reaction (PCR) and sequencing after karyotype analysis. The mutations detected were then aligned with a random sample of 100 normal sequences and the NCBI sequence database in order to confirm any new mutations. Furthermore, the copy number of SOX9 was measured by fluorescence quantitative PCR. Seven of the 10 male sex reversal patients (46, XX) contained an excess copy of the SRY gene, while one of the eight female sex reversal patients (46, XY) was lacking the SRY gene. Additionally, a new mutation (T-A, Asp24Lys) was detected in one female sex reversal patient (46, XY). No other mutation was detected in the analysis of SOX9 and DAX1, with the exception of an insertion mutation (c.35377791insG) found in the testicular-specific enhancer (TESCO) sequences in an SRY-positive female sex reversal patient (46, XY). Eight of the 18 sex reversal cases (44.4%) showed obvious connections with SRY gene translocations, mutations, or deletions, which was significantly higher than that reported previously (33.3%), indicating a need to further expand the range of sample collection. Overall, these results indicated that the main mechanism of sex reversal are not associated with mutations in the coding regions of SOX9 and DAX1 or copy number variations of SOX9, which is consistent with results of previous studies.

Two males with SRY-positive 46,XX testicular disorder of sex development.

The 46,XX testicular disorder of sex development (46,XX testicular DSD) is a rare phenotype associated with disorder of the sex chromosomes. We describe the clinical, molecular, and cytogenetic findings of a 16- and a 30-year-old male patient with sex-determining region Y (SRY)-positive 46,XX testicular DSD. Chromosomal analysis revealed 46,XX karyotype. Fluorescence in situ hybridization (FISH) showed the SRY region translocated to the short arm of the X chromosome. The presence of the SRY gene was also confirmed by polymerase chain reaction (PCR). The X chromosome inactivation (XCI) assay showed that both patients have a random pattern of X chromosome inactivation. This report compares the symptoms and features of the SRY-positive 46,XX testicular DSD patients.

Splenogonadal fusion and sex reversal.

Splenogonadal fusion is a rare congenital malformation where an abnormal union occurs between the spleen and gonad or mesonephric derivatives. Although it occurs in females it is much less prevalent than in males (male:female ratio, 16:1), but this may partly be because of the inaccessibility of the female gonads leading to under-diagnosis. To our knowledge this is the first case of splenogonadal fusion associated with sex reversal reported in the literature.

Mammalian sex determination­insights from humans and mice.

Disorders of sex development (DSD) are congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. Many of the genes required for gonad development have been identified by analysis of DSD patients. However, the use of knockout and transgenic mouse strains have contributed enormously to the study of gonad gene function and interactions within the development network. Although the genetic basis of mammalian sex determination and differentiation has advanced considerably in recent years, a majority of 46,XY gonadal dysgenesis patients still cannot be provided with an accurate diagnosis. Some of these unexplained DSD cases may be due to mutations in novel DSD genes or genomic rearrangements affecting regulatory regions that lead to atypical gene expression. Here, we review our current knowledge of mammalian sex determination drawing on insights from human DSD patients and mouse models.

46,XX T testicular disorder of sex development. Case report.

OBJECTIVE: We present a case of X-Y translocation with male phenotype (46,XX testicular disorder of sex development) and review the literature. METHODS: Disorders of sex development with mismatch of genetic, gonadal and phenotypic sex are quite rare, and some are due to genetic or chromosomal abnormalities. The karyotype was investigated by a cytogenetic study of peripheral blood (phytohemagglutinin-timulated lymphocyte culture over 72 hours). G-banding analysis of 25 metaphases showed a 46,XX chromosome constitution (46 chromosomes with XX sexual composition). Fluorescence in situ hybridization (FISH) analysis with probes for X centromeres and the sex-determining region of the Y chromosome (SRY) (testis-determining factor gene) showed two X chromosomes. The analysis also showed the SRY signal in the telomeric region of the short arm of one of the chromosomes. RESULTS: In recent years, a number of other genes involved in disorders of sex development in animals and humans have also been identified. Genetic defects in the peptide hormone receptors, members of the steroid receptor superfamily, and other transcription factors, as well as any of a series of enzymes and cofactors involved in steroid biosynthesis can cause abnormal determination and differentiation. CONCLUSIONS: Although chromosomal abnormalities are rarely present in patients with apparently normal external genitalia, they should be considered in urology consultations by adolescents and adults, particularly in the investigation of gynecomastia or infertility.

Identification of SOX3 as an XX male sex reversal gene in mice and humans.

Sex in mammals is genetically determined and is defined at the cellular level by sex chromosome complement (XY males and XX females). The Y chromosome-linked gene sex-determining region Y (SRY) is believed to be the master initiator of male sex determination in almost all eutherian and metatherian mammals, functioning to upregulate expression of its direct target gene Sry-related HMG box-containing gene 9 (SOX9). Data suggest that SRY evolved from SOX3, although there is no direct functional evidence to support this hypothesis. Indeed, loss-of-function mutations in SOX3 do not affect sex determination in mice or humans. To further investigate Sox3 function in vivo, we generated transgenic mice overexpressing Sox3. Here, we report that in one of these transgenic lines, Sox3 was ectopically expressed in the bipotential gonad and that this led to frequent complete XX male sex reversal. Further analysis indicated that Sox3 induced testis differentiation in this particular line of mice by upregulating expression of Sox9 via a similar mechanism to Sry. Importantly, we also identified genomic rearrangements within the SOX3 regulatory region in three patients with XX male sex reversal. Together, these data suggest that SOX3 and SRY are functionally interchangeable in sex determination and support the notion that SRY evolved from SOX3 via a regulatory mutation that led to its de novo expression in the early gonad.