A minority of 46,XX true hermaphrodites are positive for the Y-DNA sequence including SRY

An azoospermic male with a novel chromosome 46, XX, der(15)t(Y; 15)(p11.3; p12)

Male individuals with a 46, XX karyotype are commonly diagnosed with 46, XX male sex reversal syndrome, one of the rarest sex chromosomal anomalies. In this case, we report a rare XX male with Y‐specific DNA sequences located near the end of chromosome 15 p‐arm, which was verified by fluorescent in situ hybridization (FISH) as well as copy number variation sequencing (CNV‐seq) based on the next‐ generation sequencing method (>100 Kb). To the best of our knowledge, there have been no reports of XX male with the Yp region transferred to the terminal of chromosome 15 short arm.

We report an azoospermia male with a novel chromosome 46, xx, der(15)t(Y; 15)(p11.3; p12) by CNV‐seq combined with traditional karyotype analysis and FISH. To the best of our knowledge, there have been no reports of XX male with the Yp region transferred to the terminal of chromosome 15 short arm.

Identification of an SRY-negative 46,XX infertility male with a heterozygous deletion downstream of SOX3 gene

Background

A male individual with a karyotype of 46,XX is very rare. We explored the genetic aetiology of an infertility male with a kayrotype of 46,XX and SRY negative.

Methods

The peripheral blood sample was collected from the patient and subjected to a few genetic testing, including chromosomal karyotyping, azoospermia factor (AZF) deletion, short tandem repeat (STR) analysis for AMELX, AMELY and SRY, fluorescence in situ hybridization (FISH) with specific probes for CSP 18/CSP X/CSP Y/SRY, chromosomal microarray analysis (CMA) for genomic copy number variations(CNVs), whole-genome analysis(WGA) for genomic SNV&InDel mutation, and X chromosome inactivation (XCI) analysis.

Results

The patient had a karyotype of 46,XX. AZF analysis showed that he missed the AZF region (including a, b and c) and SRY gene. STR assay revealed he possessed the AMELX in the X chromosome, but he had no the AMELY and SRY in the Y chromosome. FISH analysis with CSP X/CSP Y/SRY showed only two X centromeric signals, but none Y chromosome and SRY. The above results of the karyotype, FISH and STR analysis did not suggest a Y chromosome chimerism existed in the patient's peripheral blood. The result of the CMA indicated a heterozygous deletion with an approximate size of 867 kb in Xq27.1 (hg19: chrX: 138,612,879–139,480,163 bp), located at 104 kb downstream of SOX3 gene, including F9, CXorf66, MCF2 and ATP11C. WGA also displayed the above deletion fragment but did not present known pathogenic or likely pathogenic SNV&InDel mutation responsible for sex determination and development. XCI assay showed that he had about 75% of the X chromosome inactivated.

Conclusions

Although the pathogenicity of 46,XX male patients with SRY negative remains unclear, SOX3 expression of the acquired function may be associated with partial testis differentiation of these patients. Therefore, the CNVs analysis of the SOX3 gene and its regulatory region should be performed routinely for these patients.

Molecular Characterization of XX Maleness

Androgens and anti-Müllerian hormone (AMH), secreted by the foetal testis, are responsible for the development of male reproductive organs and the regression of female anlagen. Virilization of the reproductive tract in association with the absence of Müllerian derivatives in the XX foetus implies the existence of testicular tissue, which can occur in the presence or absence of SRY. Recent advancement in the knowledge of the opposing gene cascades driving to the differentiation of the gonadal ridge into testes or ovaries during early foetal development has provided insight into the molecular explanation of XX maleness.

Molecular cytogenetic analysis and genetic counseling: a case report of eight 46,XX males and a literature review

Background

46,XX male syndrome is a rare disorder that usually causes infertility. This study was established to identify the genetic causes of this condition in a series of 46,XX males through the combined application of cytogenetic and molecular genetic techniques.

Case presentation

We identified eight azoospermic 46,XX males who underwent infertility-related consultations at our center. They all presented normal male phenotypes. In seven of the eight 46,XX males (87.5%), translocation of the SRY gene to the terminal short arm of the X chromosome was clearly involved in their condition, which illustrated that this translocation is the main mechanism of 46,XX sex reversal, in line with previous reports. However, one patient presented a homozygous DAX1 mutation (c.498G > A, p.R166R), which was not previously reported in SRY-negative XX males.

Conclusions

We proposed that this synonymous DAX1 mutation in case 8 might not be associated with the activation of the male sex-determining pathway, and the male phenotype in this case might be regulated by some unidentified genetic or environmental factors. Hence, the detection of genetic variations associated with sex reversal in critical sex-determining genes should be recommended for SRY-negative XX males. Only after comprehensive cytogenetic and molecular genetic analyses can genetic counseling be offered to 46,XX males.

The Development of Human Genetics at the National Research Centre, Cairo, Egypt: A Story of 50 Years

This article describes my experiences over more than 50 years in initiating and maintaining research on human genetics and genomics at the National Research Centre in Cairo, Egypt, from its beginnings in a small unit of human genetics to the creation of the Center of Excellence for Human Genetics. This was also the subject of a lecture I gave at the 10th Conference of the African Society of Human Genetics, held in Cairo in November 2017, after which Professor Michèle Ramsay, president of the society, suggested that I write an autobiographical article for the Annual Review of Genomics and Human Genetics. I hope that I succeeded in the difficult assignment of summarizing the efforts of a researcher from a developing country to initiate and maintain the rapidly advancing science of human genetics and genomics in my own country and make contributions to the worldwide scientific community.

Gonadoblastoma and Papillary Tubal Hyperplasia in Ovotesticular Disorder of Sexual Development

Ovotesticular disorder of sexual development (DSD), formerly known as true hermaphroditism, is a rare form of DSD in which both testicular and ovarian tissues are present in the same individual either in a single gonad (ovotestis) or in opposite gonads with a testis and an ovary on each side. The diagnosis of ovotesticular DSD is based solely on the presence of ovarian and testicular tissue in the gonad and not on the characteristics of the internal and external genitalia, even if ambiguous. Herein, we report two patients with ovotesticular DSD-one presenting with ambiguous genitalia on the third day after birth and the other with short stature and primary amenorrhea in adolescence. Clinical and histopathological investigation revealed a sex-determining region on the Y chromosome (SRY)-positive 46,XX karyotype and bilateral ovotestes in case 1 and a 46,XY karyotype with hypergonadotropic hypogonadism and a streak gonad in one ovotestis with dysgerminoma, gonadoblastoma, and papillary tubal hyperplasia in the contralateral ovotestis in case 2. Laparoscopic examination and gonadal biopsy for histopathological diagnosis remain the cornerstones for a diagnosis of ovotesticular DSD. Moreover, SRY positivity in a 46,XX patient, a 46,XY karyotype, an intra-abdominal gonad, and the age of patient at the time of diagnosis are predictive risk factors for the development of gonadoblastoma and/or dysgerminoma in ovotesticular DSD.

A recurrent p.Arg92Trp variant in steroidogenic factor-1 (NR5A1) can act as a molecular switch in human sex development

Cell lineages of the early human gonad commit to one of the two mutually antagonistic organogenetic fates, the testis or the ovary. Some individuals with a 46,XX karyotype develop testes or ovotestes (testicular or ovotesticular disorder of sex development; TDSD/OTDSD), due to the presence of the testis-determining gene, SRY Other rare complex syndromic forms of TDSD/OTDSD are associated with mutations in pro-ovarian genes that repress testis development (e.g. WNT4); however, the genetic cause of the more common non-syndromic forms is unknown. Steroidogenic factor-1 (known as NR5A1) is a key regulator of reproductive development and function. Loss-of-function changes in NR5A1 in 46,XY individuals are associated with a spectrum of phenotypes in humans ranging from a lack of testis formation to male infertility. Mutations in NR5A1 in 46,XX women are associated with primary ovarian insufficiency, which includes a lack of ovary formation, primary and secondary amenorrhoea as well as early menopause. Here, we show that a specific recurrent heterozygous missense mutation (p.Arg92Trp) in the accessory DNA-binding region of NR5A1 is associated with variable degree of testis development in 46,XX children and adults from four unrelated families. Remarkably, in one family a sibling raised as a girl and carrying this NR5A1 mutation was found to have a 46,XY karyotype with partial testicular dysgenesis. These unique findings highlight how a specific variant in a developmental transcription factor can switch organ fate from the ovary to testis in mammals and represents the first missense mutation causing isolated, non-syndromic 46,XX testicular/ovotesticular DSD in humans.

Disorders of Sex Development with Testicular Differentiation in SRY-Negative 46,XX Individuals: Clinical and Genetic Aspects

Virilisation of the XX foetus is the result of androgen excess, resulting most frequently from congenital adrenal hyperplasia in individuals with typical ovarian differentiation. In rare cases, 46,XX gonads may differentiate into testes, a condition known as 46,XX testicular disorders of sex development (DSD), or give rise to the coexistence of ovarian and testicular tissue, a condition known as 46,XX ovotesticular DSD. Testicular tissue differentiation may be due to the translocation of SRY to the X chromosome or an autosome. In the absence of SRY, overexpression of other pro-testis genes, e.g. SOX family genes, or failure of pro-ovarian/anti-testis genes, such as WNT4 and RSPO1, may underlie the development of testicular tissue. Recent experimental and clinical evidence giving insight into SRY-negative 46,XX testicular or ovotesticular DSD is discussed.

A duplication upstream of SOX9 was not positively correlated with the SRY‑negative 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 sex‑determining region of the Y chromosome (SRY) gene was examined. This infertile male was systemically assessed by semen analysis, serum hormone testing and gonadal biopsy. Formalin‑fixed and paraffin‑embedded 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 SRY‑box 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 SRY‑negative 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.

New insights in the clockwork mechanism regulating lineage specification: Lessons from the Drosophila nervous system

BACKGROUND

Powerful transcription factors called fate determinants induce robust differentiation programs in multipotent cells and trigger lineage specification. These factors guarantee the differentiation of specific tissues/organs/cells at the right place and the right moment to form a fully functional organism. Fate determinants are activated by temporal, positional, epigenetic, and post-transcriptional cues, hence integrating complex and dynamic developmental networks. In turn, they activate specific transcriptional/epigenetic programs that secure novel molecular landscapes.

RESULTS

In this review, we use the Drosophila Gcm glial determinant as a model to discuss the mechanisms that allow lineage specification in the nervous system. The dynamic regulation of Gcm via interlocked loops has recently emerged as a key event in the establishment of stable identity. Gcm induces gliogenesis while triggering its own extinction, thus preventing the appearance of metastable states and neoplastic processes.

CONCLUSIONS

Using simple animal models that allow in vivo manipulations provides a key tool to disentangle the complex regulation of cell fate determinants.

Unique karyotype: mos 46,X,dic(X;Y)(p22.33;p11.32)/ 45,X/45,dic(X;Y)(p22.33;p11.32) in an Egyptian patient with Ovotesticular disorder of sexual development

Ovotesticular disorder of sexual development (OT-DSD) is an unusual form of DSD, characterized by the coexistence of testicular and ovarian tissue in the same individual. In this report, we present clinical, cytogenetic and molecular data of an Egyptian patient with ambiguous genitalia and OT-DSD, who had a unique karyotype comprising 3 different cell lines: mos 46,X,dic(X;Y)(p22.33;p11.32)/45,X/ 45,dic(X;Y)(p22.33;p11.32). This mosaic karyotype probably represents 2 different events: abnormal recombination between the X and Y chromosomes during paternal meiosis and postzygotic abnormality in mitotic segregation of the dic(X;Y) chromosome, resulting in a mosaic karyotype. The presence of the sex-determining region Y (SRY) gene explains the development of testicular tissue. On the other hand, other factors, including the presence of a 45,X cell line, partial SRY deletion, X inactivation pattern, and position effect, could be contributed to genital ambiguity. Explanation of the patient's phenotype in relation to the genotype is discussed with a literature review. We conclude that FISH analysis with X- and Y-specific probes and molecular analysis of the SRY gene are highly recommended and allow accurate diagnosis for optimal management of cases with ambiguous genitalia.

Clinical, cytogenetic, and molecular analysis with 46,XX male sex reversal syndrome: case reports

PURPOSE

To investigate the clinical characteristics of different categories of sex-reversed 46,XX individuals and their relationships with chromosomal karyotype and the SRY gene.

METHODS

Chromosome karyotyping for peripheral blood culture and multi-PCR and FISH were performed.

RESULTS

Endocrinological data showed that their endocrine hormone levels were similar to that observed for Klinefelter syndrome, with higher FSH and LH levels and lower T levels. Chromosome karyotyping for peripheral blood culture revealed 46, XX complement for 11 males. Molecular studies showed that there were locus deletions at SY84, SY86, SY127, SY134, SY254 and SY255 in AZF on chromosome Y in 9 cases, with the SRY gene present at the terminus of the X chromosome short arm. In one case, besides 6 locus deletions in AZF, there was also SRY gene deletion. In another case, there were locus deletions only at SY254 and SY255, with SY84, SY86, SY127 SY134 loci and SRY present.

CONCLUSIONS

The majority (10/11) of 46,XX males were SRY positive, with the SRY gene translocated into the terminus of the X chromosome short arm. These patients were caused mainly by an X/Y chromosomal inter-change during paternal meiosis, leading to the differentiation of primary gonads into testes. Only a single patient (1/11) was SRY-negative, in which there might be some unknown downstream genes involved in sex determination.

Is 46XX karyotype always a female?

A19-year-old man, from a middle east country was referred by his physician to the endocrine department for bilateral gynaecomastia, low libido and sparse facial hair. There was no history of any chronic illness, mumps or traumatic injury to testis. He had clinical features suggestive of gonadotropin deficiency which was confirmed on biochemical testing. On karyotype and fluorescent in situ hybridisation analysis, he was found to have 46XX(SRY+) karyotype.

Mammalian sex determination—insights 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.

Long-term outcome of ovotesticular disorder of sex development: a single center experience

OBJECTIVES

To describe the clinical features of children with ovotesticular disorder of sex development (DSD) and to review cases of ovotesticular DSD in Japan.

METHODS

Medical records of eight children diagnosed with ovotesticular DSD at our institute during the past 17 years were retrospectively evaluated. A review of 165 reported cases of ovotesticular DSD from Japanese institutions was carried out.

RESULTS

Mean follow up was 8.2 years for six children, with two children lost to follow up. Mean age at first presentation was 2.4 months. All children were Japanese. The most common initial manifestation was ambiguous genitalia. The female:male ratio as the sex of rearing was 1:1. Gender reassignment, from male to female, was carried out in one child at 4-months-old. Genital surgery was always carried out in early childhood as per family desire. Appropriate gonadal tissue was preserved except for one child. No gonadal tumors were detected during follow up. Spontaneous pubertal development occurred in one boy. In reviewing Japanese data, the frequency of testes was higher than in other ethnicities and this was related to the higher incidence of 46,XY.

CONCLUSIONS

According to our experience, most families in Japan desire early genital surgery in the case of ovotesticular DSD. Chromosomal and gonadal distributions in patients with ovotesticular DSD differ between Japanese and other ethnic groups. Treatment for these patients needs to be provided after considering the cultural and social backgrounds of DSD in Japan.

A 3-year-old boy with ovotestes: gender reassignment and surgical management

OBJECTIVE

We report a male patient with ovotesticular disorder of sex development (OTDSD), resulting from structurally abnormal Y chromosome.

CASE REPORT

A 3-year-old boy was admitted to the Surgical Pediatric Department for masculinizing reconstruction. He had a clitorophallus, bifid scrotum, perineal hypospadias and bilateral impalpable gonads. Pelvic ultrasound and laparoscopy showed a uterus and two gonads with primary ovarian follicles. Chromosome analysis detected a mos 47,XX,mar/46,XX karyotype. Complex genetic evaluation revealed that the marker was Yp isochromosome. Surgical care included a feminizing genitoplasty and separation of the gonads with total excision of testicular tissue.

CONCLUSIONS

The presented case emphasizes the importance of a systematic approach to the investigation and management of the patients with ovotesticular DSD. It also raises the important issue about gender reassignment in intersex individuals in mid-childhood.

New technologies for the identification of novel genetic markers of disorders of sex development (DSD)

Although the genetic basis of human sexual determination and differentiation has advanced considerably in recent years, the fact remains that in most subjects with disorders of sex development (DSD) the underlying genetic cause is unknown. Where pathogenic mutations have been identified, the phenotype can be highly variable, even within families, suggesting that other genetic variants are influencing the expression of the phenotype. This situation is likely to change, as more powerful and affordable tools become widely available for detailed genetic analyses. Here, we describe recent advances in comparative genomic hybridisation, sequencing by hybridisation and next generation sequencing, and we describe how these technologies will have an impact on our understanding of the genetic causes of DSD.

Genes and phenotypes of the human Y chromosome

By 1959 it was recognized that the gene (or genes) responsible for initiating the human male phenotype were carried on the Y chromosome. But in subsequent years, few phenotypes were associated with the Y chromosome. Recently, using molecular techniques combined with classical genetics, the Y chromosome has been the focus of intensive and productive investigation. Some of the findings are unexpected and have extended our understanding of the functions of the human Y chromosome. The notion that the Y chromosome is largely devoid of genes is changing. At the present, over 20 Y chromosome genes or pseudogenes have been identified or cloned, a number that is rapidly increasing. A high proportion of Y chromosome sequences have been found to be related to X chromosome sequences: the assembly of a complete physical map of the Y chromosome euchromatic region (believed to carry all of the genes) has shown 25% of the region studied to have homology to the X chromosome.3 Several X-homologous genes are located in the X and Y chromosome pairing regions, an area predicted to have shared homology. Surprisingly, some of the Y-encoded genes that lie outside of the X and Y pairing region share high sequence similarity, and in at least one case, functional identity, with genes on the X chromosome.

Minimal external masculinization in a SRY-negative XX male Podenco dog

Normal mammalian sex differentiation takes place in three genetically controlled steps: chromosomal sex determination (XX or XY), gonadal differentiation and development of the phenotypic sex. Animals are considered to be sex reversed if chromosomal sex determination and gonadal development are not in agreement. In this report, sex reversal is described in a 1.5-year-old Podenco dog that was referred because of suspected recurrent growth of a previously removed os clitoridis in the vulva. With that exception the dog was phenotypically female, but had never been in oestrus and exhibited male behaviour. Abdominal ultrasonography showed a small tubular structure dorsal to the bladder, consistent with a uterus. An ovoid structure resembling a gonad was visible between the right kidney and inguinal canal. Plasma testosterone concentrations before and after GnRH administration indicated the presence of functional testicular tissue. Two testes, each with its epididymis and ductus deferens, and a complete bicornuate uterus were removed surgically. Cytogenetic analysis of peripheral blood lymphocytes showed a normal female karyotype (78, XX). These findings are consistent with the diagnosis of an XX male. PCR analysis of genomic DNA revealed that the SRY gene was absent. In summary, this report describes the first SRY-negative XX male Podenco dog with an almost complete female phenotype despite high basal and stimulated plasma testosterone concentrations. It is hypothesized that the clinical observations in this dog may have been caused by reduced and delayed Müllerian-inhibiting substance secretion and the absence of conversion of testosterone to dihydrotestosterone due to 5alpha-reductase deficiency.

An XX male with an intratubular undifferentiated germ cell neoplasia

OBJECTIVE

To report a case of a 46,XX male with an intratubular undifferentiated germ cell neoplasia within an extra-abdominal gonad.

DESIGN

Case report.

SETTING

Molecular, cytogenetic, pathologic, and clinical units of three tertiary hospitals.

PATIENT(S)

A male with ambiguous genitalia at birth and descended testes observed in a pediatric endocrinology setting.

INTERVENTION(S)

Physical examination, hormonal assays, cytogenetic investigation, molecular analysis, surgical intervention for biopsies and bilateral orchiectomy, and pathologic evaluation.

MAIN OUTCOME MEASURE(S)

Pathologic evaluation with immunostaining for placental alkaline phosphatase and C-kit.

RESULT(S)

Conventional chromosome analysis revealed a 46,XXq- karyotype, and fluorescence in situ hybridization experiments with the SRY probe found a signal at the short arm of the deleted X chromosome. Molecular analysis indicated the presence of a portion of the short arm of the Y chromosome including the proto-oncogene TSPY. Pathologic evaluation of the gonads revealed an intratubular undifferentiated germ cell neoplasia.

CONCLUSION(S)

This is the first case of a 46,XX male with descended testes in whom an intratubular undifferentiated germ cell neoplasia developed. When proposals of management in this subgroup of disorders of sexual differentiation are formulated, the risk of germ cell malignancy must be taken into account.

Clinical value of PTEN in patients with superficial bladder cancer

INTRODUCTION

Frequent mutations or deletions of PTEN (phosphatase and tensin homolog deleted on chromosome 10) are reported in bladder cancer, while there are few studies which evaluated PTEN as a clinical prognostic parameter of superficial bladder cancer. We prospectively evaluated PTEN expression in patients with superficial bladder cancer by immunohistochemical staining and defined the value of PTEN mutations in predicting tumor behavior of superficial bladder cancer.

MATERIALS AND METHODS

A total of 190 patients were enrolled in this study. All of the patients underwent transurethral resection of bladder tumor and had superficial tumors. All pathologic materials used in this study were obtained from transurethral resection of bladder tumor. Immunohistochemical stainings were performed. The immunohistochemical staining intensity was judged to be either normal or reduced compared with the PTEN protein expression of positive and negative controls. Disappearance of more than 50% stained cytoplasmic granules was defined as reduced PTEN expression.

RESULTS

The alteration of PTEN expression was significantly different according to tumor stage and grade (p = 0.03, p = 0.048), especially high in carcinoma in situ. However, PTEN expression was not significantly correlated with disease recurrence, progression and recurrence- or progression-free survival.

CONCLUSIONS

Reduced PTEN expression relates to aggressiveness of bladder tumors but seems not to have enough specificity for clinical use in the management of superficial bladder cancer.

Genetics, genomics, and molecular biology of sex determination in small animals

The genomic revolution is beginning to facilitate advances in canine and feline medicine, as illustrated in our research. Our studies are focused upon identifying the gene mutation that causes canine Sry-negative XX sex reversal, a disorder of sex determination in which chromosomal females (78,XX) develop testicular tissue, becoming either XX true hermaphrodites with ovotestes, or XX males with bilateral testes. A genome-wide screen, using mapped markers in our pedigree of Sry-negative XX sex reversed dogs founded upon the American cocker spaniel, identified five chromosomal regions in which the causative gene may be located. The canine genome was used to identify the canine homologue of goat Pisrt1 and so determine that canine and caprine Sry-negative XX sex reversal are genetically heterogeneous. A second goal of our research is to determine the molecular mechanism by which the mutation causes testis induction. Thus far, we have reported gonadal Sry and Sox9 expression patterns in normal embryos, which have temporal and spatial patterns similar to those reported in humans, sheep, and pigs. Once gene mutations causing such inherited disorders are identified, DNA tests will become a part of general veterinary practice, advancing both diagnostic techniques and preventative medicine.

An XX male with the sex-determining region Y gene inserted in the long arm of chromosome 16

OBJECTIVE

To report a case of a 46,XX male with an insertion of the sex-determining region Y (SRY) region in the terminal end of the long arm of chromosome 16.

DESIGN

Case report.

SETTING

Molecular and cytogenetic units in a university hospital.

PATIENT(S)

An infertile male, with normal masculinization of the external genitalia, who was referred for chromosomal analysis as an unaffected member of a family with idiopathic hypertrophic osteoarthropathy.

INTERVENTION(S)

Cytogenetic investigation, physical examination, and hormonal assays.

MAIN OUTCOME MEASURE(S)

Chromosomal analysis using GTG banding and fluorescence in situ hybridization (FISH).

RESULT(S)

Conventional chromosome analysis revealed a normal 46,XX karyotype. The FISH with bacterial artificial chromosomes (BACs) of the SRY region indicated the presence of this region on the terminal end of the long arm of chromosome 16.

CONCLUSION(S)

This is the first case of a 46,XX male with the SRY gene present on an autosome-here chromosome 16. The size of the inserted region containing SRY, inserted in 16qter, is approximately 600 kb.

Phenotype in X chromosome rearrangements: pitfalls of X inactivation study

OBJECTIVE

X inactivation pattern in X chromosome rearrangements usually favor the less unbalanced cells. It is correlated to a normal phenotype, small size or infertility. We studied the correlation between phenotype and X inactivation ratio in patients with X structural anomalies.

PATIENTS AND METHODS

During the 1999-2005 period, 12 X chromosome rearrangements, including three prenatal cases, were diagnosed in the Laboratoire de Cytogénétique of Strasbourg. In seven cases, X inactivation ratio could be assessed by late replication or methylation assay.

RESULTS

In three of seven cases (del Xp, dup Xp, t(X;A)), X inactivation ratio and phenotype were consistent. The four other cases showed discrepancies between phenotype and X inactivation pattern: mental retardation and dysmorphism in a case of balanced X-autosome translocation, schizophrenia and autism in two cases of XX maleness and MLS syndrome (microphthalmia with linear skin defects) in a case of Xp(21.3-pter) deletion.

CONCLUSION

Discrepancies between X inactivation ratio and phenotype are not rare and can be due to gene disruption, position effect, complex microrearrangements, variable pattern of X inactivation in different tissues or fortuitous association. In this context, the prognostic value of X inactivation study in prenatal diagnosis will be discussed.

Complex mosaicism in sex reversed SRY+ male twins

Sex reversal is characterized by discordance between genetic and phenotypic sex. Most XX males result from an unequal interchange between X and Y chromosomes during paternal meiosis, therefore transferring SRY to the X chromosome, which explains the male development in the presence of an otherwise normal female karyotype. We present here the case of sex reversed SRY+ male twins with several cell lines. They consulted for infertility. The presence of SRY on an X chromosome was demonstrated by FISH. Their respective karyotypes were: 46,X,der(X)t(X;Y)(p22.3;p11.2)[249]/45,X [12]/45,der(X)t(X;Y)(p22.3;p11.2)[11]/47,XX,der(X)t(X;Y) (p22.3;p11.2)[1]/47,X,der(X)t(X;Y)(p22.3;p11.2)x2[1]/50, XX,der(X)t(X;Y)(p22.3;p11.2)x4[1]/46,XX[1] for the first twin (SH-1) and 46,X,der(X)t(X;Y)(p22.3;p11.2)[108]/45,X [3]/47,XX,der(X)t(X;Y)(p22.3;p11.2)[2]/45,der(X)t(X;Y) (p22.3;p11.2)[1]/47,X,der(X)t(X;Y)(p22.3;p11.2)x2[1] for the second twin (SH-2). There are three different types of XX males: 1) with normal genitalia, 2) with genital ambiguity, and 3) XX true hermaphrodites. The phenotype of the twins presented in this report is consistent with what is generally seen in XX SRY+ males: they have normal genitalia.

Sf1 and Mis expression: molecular milestones in the canine sex determination pathway

In mammals, the Y-linked Sry gene is normally responsible for testis induction. However, testes develop in the absence of Sry in human patients and animal models with Sry-negative XX sex reversal. The mechanism of testis induction in this disorder is presently unknown. Characterization of gene expression in normal embryos contributes to the framework within which the canine Sry-negative XX sex reversal model can be evaluated. The objective of this study was to add two molecular milestones to the canine sex determination pathway by determining the temporal and spatial expression patterns of Sf1 and Mis in normal urogenital ridges (UGR) at various gestational stages. The onset of Sf1 expression signifies the start of the sex determination period, whereas initial Mis expression identifies the end of the testis induction period. Sf1 expression in UGR was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and whole mount in situ hybridization (WMISH) at Carnegie stages (CS) 15 to 20. Canine sex determination begins at CS 15 with Sf1 expression in the emerging indifferent gonad. Gonadal Sf1 expression was detected in both sexes at all ages, and in the presumptive adrenal primordium at CS 15 and 17. At stages > or = CS 17, Sf1 expression was pronounced in male and female gonads. Mis expression, assayed by WMISH at CS 13.5-20, was observed only in male gonads > or = CS 18, indicating that the testis induction period ends at CS 18. The expression patterns of both genes are similar to those observed in humans and domestic animals.

Skewed X-chromosome inactivation pattern in SRY positive XX maleness: a case report and review of literature

XX maleness is the most common condition in which testes develop in the absence of a cytogenetically detectable Y chromosome. Using fluorescence in situ hybridization (FISH) or PCR, it was possible to detect the transfer of Yp fragments including SRY gene to the terminal part of X chromosome in the majority of XX males. We report a 32-year-old-male in whom a seminal analysis showed azoospermia, an X chromatin analysis showed 44% of Barr body positive nuclei and a chromosomal analysis revealed a 46,XX karyotype. Physical examination showed a normal sexual development and bilateral small testes. Hormonal studies revealed hypergonadotropic hypogonadism. Testis histological examination showed a profile of Sertoli Only Cell Syndrome. FISH study ruled out the presence of a Y-bearing cell line, and confirmed translocation of SRY to Xp terminal part. In order to confirm that the complete masculinized phenotype was related to a preferential inactivation of the no rearranged X chromosome, X-chromosome inactivation patterns (XCIP) were studied by analysis of methylation status of the androgen receptor gene. Highly skewed XCIP was observed by greater than 90% preferential inactivation involving one of the two X chromosomes, suggesting that the SRY-bearing X chromosome was the preferentially active X allowing for sufficient SRY expression for complete masculinization.

Ontogenesis of female-to-male sex-reversal in XX polled goats

The association of polledness and intersexuality in domestic goats (PIS mutation) made them a practical genetic model for studying mammalian female-to-male sex reversal. In this study, gonads from XX sex-reversed goats (PIS-/-) were thoroughly characterized at the molecular and histologic level from the first steps of gonadal differentiation (36 days post coitum [dpc]) to birth. The first histologic signs of gonadal sex reversal were detectable between 36 and 40 dpc (4-5 days later than the XY male) and were mainly characterized by the reduction of the ovarian cortex and the organization of seminiferous cords. As early as 36 dpc, aromatase (CYP19) gene expression was decreased in XX (PIS-/-) gonads, whereas genes normally up-regulated in males, such as SOX9 and AMH, showed an increased expression level from 40 dpc. Thereafter, steroidogenic cell precursors were affected, and at 56 dpc, WNT4 and 3beta-HSD were expressed in a male-specific manner in sex-reversed gonads. Another noticeable feature was a progressive disappearance of germ cells, clearly visible in testicular cords around 70 dpc where 50-75% of germ cells were absent in XX (PIS-/-) gonads. These observations indicated that the causal mutation of PIS acts very early in the sex-determining cascade and affects primarily the supporting cells of the gonad.

46,XX sex reversal

In humans, sexual differentiation is directed by SRY, a master regulatory gene located at the Y chromosome. This gene initiates the male pathway or represses the female pathway by regulating the transcription of downstream genes; however, the precise mechanisms by which SRY acts are largely unknown. Moreover, several genes have recently been implicated in the development of the bipotential gonad even before SRY is expressed. In some individuals, the normal process of sexual differentiation is altered and a sex reversal disorder is observed. These subjects present the chromosomes of one sex but the physical attributes of the other. Over the past years, considerable progress has been achieved in the molecular characterization of these disorders by using a combination of strategies including cell biology, animal models, and by studying patients with these pathologic entities.

A man who inherited his SRY gene and Leri-Weill dyschondrosteosis from his mother and neurofibromatosis type 1 from his father

We report on a man with neurofibromatosis type 1 (NF1) and Leri-Weill dyschondrosteosis (LWD). His father had NF1. His mother had LWD plus additional findings of Turner syndrome (TS): high arched palate, bicuspid aortic valve, aortic stenosis, and premature ovarian failure. The proband's karyotype was 46,X,dic(X;Y)(p22.3;p11.32). Despite having almost the same genetic constitution as 47,XXY Klinefelter syndrome, he was normally virilized, although slight elevation of serum gonadotropins indicated gonadal dysfunction. His mother's karyotype was mosaic 45,X[17 cells]/46,X,dic(X;Y)(p22.3;p11.32)[3 cells].ish dic(X;Y)(DXZ1 +,DYZ1 + ). The dic(X;Y) chromosome was also positive for Y markers PABY, SRY, and DYZ5, but negative for SHOX. The dic(X;Y) chromosome was also positive for X markers DXZ1 and a sequence < 300 kb from PABX, suggesting that the deletion encompassed only pseudoautosomal sequences. Replication studies indicated that the normal X and the dic(X;Y) were randomly inactivated in the proband's lymphocytes. LWD in the proband and his mother was explained by SHOX haploinsufficiency. The mother's female phenotype was most likely due to 45,X mosaicism. This family segregating Mendelian and chromosomal disorders illustrates extreme sex chromosome variation compatible with normal male and female sexual differentiation. The case also highlights the importance of karyotyping for differentiating LWD and TS, especially in patients with findings such as premature ovarian failure or aortic abnormalities not associated with isolated SHOX haploinsufficiency.

Sex chromosomes and sex-determining genes: insights from marsupials and monotremes

Comparative studies of the genes involved in sex determination in the three extant classes of mammals, and other vertebrates, has allowed us to identify genes that are highly conserved in vertebrate sex determination and those that have recently evolved roles in one lineage. Analysis of the conservation and function of candidate sex determining genes in marsupials and monotremes has been crucial to our understanding of their function and positioning in a conserved mammalian sex-determining pathway, as well as their evolution. Here we review comparisons between genes in the sex-determining pathway in different vertebrates, and ask how these comparisons affect our views on the role of each gene in vertebrate sex determination.

XX males without SRY gene and with infertility

The case of a 28 year old male with normal male phenotype, in whom repeated seminal analysis showed complete azoospermia, is presented. Peripheral blood culture for chromosome studies revealed 46 chromosomes with XX constitution. Polymerase chain reaction (PCR) analysis of genomic DNA failed to detect the presence of the sex-determining region of the Y chromosome (SRY). A literature review of all SRY-negative XX males with normal male phenotype showed that this case is the sixth reported case but the first to be diagnosed during the investigations of infertility. The frequency, aetiology and diagnosis of this rare syndrome are also reviewed.

The human sex-reversing ATRX gene has a homologue on the marsupial Y chromosome, ATRY: implications for the evolution of mammalian sex determination

Mutations in the ATRX gene on the human X chromosome cause X-linked alpha-thalassemia and mental retardation. XY patients with deletions or mutations in this gene display varying degrees of sex reversal, implicating ATRX in the development of the human testis. To explore further the role of ATRX in mammalian sex differentiation, the homologous gene was cloned and characterized in a marsupial. Surprisingly, active homologues of ATRX were detected on the marsupial Y as well as the X chromosome. The Y-borne copy (ATRY) displays testis-specific expression. This, as well as the sex reversal of ATRX patients, suggests that ATRY is involved in testis development in marsupials and may represent an ancestral testis-determining mechanism that predated the evolution of SRY as the primary mammalian male sex-determining gene. There is no evidence for a Y-borne ATRX homologue in mouse or human, implying that this gene has been lost in eutherians and its role supplanted by the evolution of SRY from SOX3 as the dominant determiner of male differentiation.

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite

Yp-specific sequences, including the testicular determinant gene SRY, have been detected and located in a 46,XX true hermaphrodite individual, using PCR amplification and fluorescent in situ hybridization (FISH). Among different Y chromosome loci tested, it was only possible to detect Yp sequences. The Y-centromere and Yq sequences were absent. Unexpectedly, the Y fragment was translocated to the long arm of one of the X chromosomes, at the Xq28 level, and the derivative (X) chromosome of the patient lacked q-telomeric sequences. To our knowledge, this is the first Yp/Xq translocation reported. The coexistence of testicular and ovarian tissue in the patient may have arisen by differential inactivation of the Y-bearing X chromosome, in which Xq telomeric sequences are missing. The possible origin of the Yp/Xq translocation, during paternal meiosis or in somatic paternal cells, is discussed.

Sex determination and the Y chromosome

Although SRY was first identified 10 years ago, we still know remarkably little about its mode of action or downstream target genes. Recently, potential protein partners have been identified and there has been considerable activity to understand the roles of WT1, SF-1, DAX-1 and SOX9 in gonadogenesis. The emerging picture is one of complex interactions, involving both positive and negative regulatory signals that, depending on the cellular and promoter context, drive the expression of male-specific genes. Despite recent advances, however, we are still unable to explain the genetic cause of most cases of 46,XY gonadal dysgenesis or even a single case of Y-chromosome-negative 46,XX maleness.

Sry-negative XX sex reversal in purebred dogs

The gene responsible for testis induction in normal male mammals is the Y-linked Sry. However, there is increasing evidence that other genes may have testis-determining properties. In XX sex reversal (XXSR), testis tissue develops in the absence of the Y chromosome. Previous polymerase chain reaction (PCR) assays indicated that autosomal recessive XXSR in the American cocker spaniel is Sry-negative. In this study, genomic DNA from the breeding colony of American cocker spaniels and from privately owned purebred dogs were tested by PCR using canine primers for the Sry HMG box and by Southern blots probed with the complete canine Sry coding sequence. Sry was not detected by either method in genomic DNA of affected American cocker spaniels or in the majority (20/21) of affected privately owned purebred dogs. These results confirm that the autosomal recessive form of XXSR in the American cocker spaniel is Sry-negative. In combination with previous studies, this indicates that Sry-negative XXSR occurs in at least 15 dog breeds. The canine disorder may be genetically heterogeneous, potentially with a different mutation in each breed, and may provide several models for human Sry-negative XXSR. A comparative approach to sex determination should be informative in defining the genetic and cellular mechanisms that are common to all mammals.

Incomplete masculinisation of XX subjects carrying the SRY gene on an inactive X chromosome

46,XX subjects carrying the testis determining SRY gene usually have a completely male phenotype. In this study, five very rare cases of SRY carrying subjects (two XX males and three XX true hermaphrodites) with various degrees of incomplete masculinisation were analysed in order to elucidate the cause of sexual ambiguity despite the presence of the SRY gene. PCR amplification of 20 Y chromosome specific sequences showed the Yp fragment to be much longer in XX males than in true hermaphrodites. FISH analysis combined with RBG banding of metaphase chromosomes of four patients showed that in all three true hermaphrodites and in one XX male the Yp fragment was translocated onto a late replicating inactive X chromosome in over 90% of their blood lymphocytes. However, in a control classical XX male with no ambiguous features, the Yp fragment (significantly shorter than in the XX male with sexual ambiguity and only slightly longer than in XX hermaphrodites) was translocated onto the active X chromosome in over 90% of cells.

These studies strongly indicate that inactivation on the X chromosome spreading into a translocated Yp fragment could be the major mechanism causing a sexually ambiguous phenotype in XX (SRY+) subjects.

Sry-negative XX true hermaphrodite in a Basset hound

A true hermaphrodite was diagnosed in a 7-mo.-old Basset hound. The diagnosis was based on the clinical signs, the histology of the gonads and the karyogram. Additionally, the dog was tested for the Y-linked gene Sry, which was negative. The Basset hound presented here is compared to other XX sex reversed animals described in the literature. In man, XX sex reversal is a heterogenous condition. The pathogenesis in Sry-negative individuals is not understood. Thus Sry-negative animals could serve as an animal model of the human disease.

Clinical and molecular analysis of XX sex reversed patients

PURPOSE

The XX male syndrome presents with a spectrum of clinical appearances from phenotypic male individuals to true hermaphrodites. Previous reports established the sex determining region of the Y chromosome (SRY) gene as the testis determining factor. However, a subset of XX sex reversed male individuals exists without a translocation of SRY deoxyribonucleic acid (DNA) material to the X chromosome. In addition to clinical or endocrinological criteria, Y DNA probe studies, and radiological and surgical evaluation as indicated are necessary for an accurate diagnosis.

MATERIALS AND METHODS

We evaluated 5 XX sex reversed patients (2 true hermaphrodites and 3 male individuals) by physical examination, pedigree analysis, endocrinological testing, molecular analysis of Y DNA, radiological studies and surgery (exploration and/or biopsy).

RESULTS

All patients were SRY gene negative. Two patients were siblings. Complete endocrinological testing was negative in all cases. Two patients had a normal male phenotype. Radiological findings confirmed by cystoscopy or laparoscopy revealed a utricle, vesicoureteral reflux, and cervix and uterus in various patients. Gonadal biopsy showed ovotestes or ovary and testis in the 2 true hermaphrodites. The 3 XX male individuals had normal immature testes on biopsy.

CONCLUSIONS

Categories of XX sex reversal include classic XX male individuals with normal phenotypes, nonclassic XX male individuals with sexual ambiguity and XX true hermaphrodites. Simple translocation of the SRY gene to the X chromosome does not always account for testicular differentiation and a male phenotype. The masculinization of our patients in the absence of SRY suggests an alteration of 1 or more downstream Y, X or autosomal testis determining genes. We present another theory for male sex determination, including a downstream gene on the X chromosome in which expression is influenced by X inactivation. Y DNA genomic analysis, radiological studies and laparoscopic evaluation with gonadal biopsy as appropriate are recommended for complete assessment and treatment of these intersex patients.

Ovotestes in B6-XXSxr sex-reversed mice

The sex-reversed mutation Sxr results in XX males. In the absence of any other mutations, testis differentiation in XXSxr fetuses is essentially normal and only one report of an XXSxr fetus with ovotestes is in the literature. We report that 84% (21/25) of 13 days postcoitum XXSxr fetuses on the B6 inbred genomic background have ovotestes. Ovotestes were found in fetuses from both Sxra and Sxrb variants. Examination of fetuses older than 13 dpc suggests that the presence of ovotestes is transient in most fetuses. However, one overt hermaphrodite was identified after birth. The development of ovotestes is associated with the inbred background and is exacerbated by the dominant spotting oncogene allele KitW-42J. We propose that spreading of X-inactivation into the Sxr region resulting in loss of Sry expression is more extensive in B6-Sxr strains.