Sex-determining Region On Y Research Articles

Genetic testing and prenatal diagnosis for two Chinese pedigrees affected with Alport syndrome due to variants of COL4A5 gene

To analysis variants of COL4A5 gene in two Chinese pedigrees affected with Alport syndrome (AS) and provide prenatal diagnosis for them. Two unrelated ethnic Han Chinese pedigrees who had visited the First Affiliated Hospital of Zhengzhou University respectively in September 2018 and January 2020 were selected as the study subjects. Clinical data were collected, and genomic DNA was extracted from peripheral venous blood and amniotic fluid samples for genetic testing. Following next generation sequencing, candidate variants of the COL4A5 gene were verified by Sanger sequencing and bioinformatic analysis. The gender of the fetuses was determined by the presence of sex-determining region on Y (SRY). Genetic testing revealed that the proband and a fetus from pedigree 1 had both harbored a c.2723G>A (p.Gly908Glu) variant in exon 32 of the COL4A5 gene, whilst the proband and a fetus from pedigree 2 had both harbored a c.3817G>A (p.Gly1273Asp) variant in exon 44 of the COL4A5 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as likely pathogenic (PP2+PM2_Supporting). Following exclusion of maternal contamination, PCR amplification of the SRY region indicated that both fetuses were males. The c.2723G>A (p.Gly908Glu) and c.3817G>A (p.Gly1273Asp) variants of the COL4A5 gene probably underlay the AS in the two pedigrees. Detection of the SRY region can reliably identify the fetal sex, which is conducive to the prenatal diagnosis. Above results have also enriched the mutational spectrum of the COL4A5 gene and provided a reference for correlating the genotype and phenotype of the AS.

The Biomarker Like the Correlation between Vasculogenic Mimicry, Vascular Endothelial Cadherin, Sex-DeterminingRegion on Y-Box Transcription Factor 17, and Cyclin D1 in Oesophageal Squamous Cell Carcinoma.

Background This study aimed to explore the relationships between the sex-determining region on Y (SRY) box transcription factor 17 (SOX17), Cyclin D1, vascular endothelial cadherin (VE-cadherin), and vasculogenic mimicry (VM) in the occurrence and development of esophageal squamous cell carcinoma (ESCC). Methods The expressions of SOX17, Cyclin D1, and VE-cadherin, as well as VM, in tissues, were determined using immunohistochemistry. SOX17, Cyclin D1, and VE-cadherin mRNA in ESCC and their corresponding adjacent normal tissues were quantified using quantitative reverse transcription polymerase chain reaction analysis. Cell invasion, migration, and proliferation were determined after the silencing of VE-cadherin. SOX17, Cyclin D1, and VE-cadherin protein were quantified using Western blotting. Results The expression levels of SOX17, Cyclin D1, and VE-cadherin significantly correlated with the clinical characteristics of ESCC. After the VE-cadherin silencing, cell invasion, migration, and proliferation decreased, along with the Cyclin D1 levels, while the SOX17 levels increased. Conclusion SOX17, Cyclin D1, and VE-cadherin are involved in the development of ESCC.

The SOX gene family: function and regulation in testis determination and male fertility maintenance

The Sox (Sry-type HMG box) genes encode a group of proteins characterized by the existence of an SRY (sex-determining region on Y chromosome) box, a 79 amino acid motif that encodes an HMG (high mobility group) domain which can bind and bend DNA, which is the only part in SRY that is conserved between species. The Sox gene family functions in many aspects in embryogenesis, including testis development, CNS neurogenesis, oligodendrocyte development, chondrogenesis, neural crest cell development and other respects. The Sox gene family was originally identified through homology with Sry. The Sry gene is the mammalian testis-determining gene. It functions to open the testis determination pathway directly and close the ovary pathway indirectly. Sry and Sox9 are the most important two genes expressed during testis determination. Besides, researchers have found that Sox8 and Sox9 have functions in the male fertility maintenance after birth. In this review, information was evaluated from mouse or from human if not mentioned otherwise.

Excess DAX1 leads to XY ovotesticular disorder of sex development (DSD) in mice by inhibiting steroidogenic factor-1 (SF1) activation of the testis enhancer of SRY-box-9 (Sox9).

Human DAX1 duplications cause dosage-sensitive sex reversal (DSS) whereby chromosomally XY individuals can develop as females due to gonadal dysgenesis. However, the mechanism of DSS-adrenal hypoplasia congenita on X, gene 1 (DAX1) action in the fetal testis is unknown. We show that in fetal testes from XY Dax1-overexpressing transgenic mice, the expression of the key testis-promoting gene sex-determining region on Y (SRY)-box-9 (Sox9) is reduced. Moreover, in XY Sox9 heterozygotes, in which testis development is usually normal, Dax1 overexpression results in ovotestes, suggesting a DAX1-SOX9 antagonism. The ovarian portion of the XY ovotestes was characterized by expression of the granulosa cell marker, Forkhead box-L2, with complete loss of the Sertoli cell markers, SOX9 and anti-Müllerian hormone, and the Leydig cell marker CYP17A1. However, the expression of SRY and steroidogenic factor-1 (SF1), two key transcriptional regulators of Sox9, was retained in the ovarian portion of the XY ovotestes. Using reporter mice, Dax1 overexpression reduced activation of TES, the testis enhancer of Sox9, indicating that DAX1 might repress Sox9 expression via TES. In cultured cells, increasing levels of DAX1 antagonized SF1-, SF1/SRY-, and SF1/SOX9-mediated activation of TES, due to reduced binding of SF1 to TES, providing a likely mechanism for DSS.

Challenges in clinical and laboratory diagnosis of androgen insensitivity syndrome: a case report

IntroductionAndrogen is a generic term usually applied to describe a group of sex steroid hormones. Androgens are responsible for male sex differentiation during embryogenesis at the sixth or seventh week of gestation, triggering the development of the testes and penis in male fetuses, and are directed by the testicular determining factor: the gene SRY (sex determining region on Y chromosome) located on the short arm of chromosome Y. The differentiation of male external genitalia (penis, scrotum and penile urethra) occurs between the 9th and 13th weeks of pregnancy and requires adequate concentration of testosterone and the conversion of this to another more potent androgen, dihydrotestosterone, through the action of 5α-reductase in target tissues.Case presentationThis report describes the case of a teenage girl presenting with a male karyotype, and aims to determine the extension of the mutation that affected the AR gene. A Caucasian girl aged 15 was referred to our laboratory for genetic testing due to primary amenorrhea. Physical examination, karyotype testing and molecular analysis of the androgen receptor were critical in making the correct diagnosis of complete androgen insensitivity syndrome.ConclusionsSex determination and differentiation depend on a cascade of events that begins with the establishment of chromosomal sex at fertilization and ends with sexual maturation at puberty, subsequently leading to fertility. Mutations affecting the AR gene may cause either complete or partial androgen insensitivity syndrome. The case reported here is consistent with complete androgen insensitivity syndrome, misdiagnosed at birth, and consequently our patient was raised both socially and educationally as a female. It is critical that health care providers understand the importance of properly diagnosing a newborn manifesting ambiguous genitalia. Furthermore, a child with a pseudohermaphrodite phenotype should always undergo adequate endocrine and genetic testing to reach a conclusive diagnosis before gender is assigned and surgical interventions are carried out. Our results show that extreme care must be taken in selecting the genetic tools that are utilized for the diagnosis for androgen insensitivity syndrome.

Failure of SOX9 Regulation in 46XY Disorders of Sex Development with SRY, SOX9 and SF1 Mutations

BackgroundIn human embryogenesis, loss of SRY (sex determining region on Y), SOX9 (SRY-related HMG box 9) or SF1 (steroidogenic factor 1) function causes disorders of sex development (DSD). A defining event of vertebrate sex determination is male-specific upregulation and maintenance of SOX9 expression in gonadal pre-Sertoli cells, which is preceded by transient SRY expression in mammals. In mice, Sox9 regulation is under the transcriptional control of SRY, SF1 and SOX9 via a conserved testis-specific enhancer of Sox9 (TES). Regulation of SOX9 in human sex determination is however poorly understood.Methodology/Principal FindingsWe show that a human embryonal carcinoma cell line (NT2/D1) can model events in presumptive Sertoli cells that initiate human sex determination. SRY associates with transcriptionally active chromatin in NT2/D1 cells and over-expression increases endogenous SOX9 expression. SRY and SF1 co-operate to activate the human SOX9 homologous TES (hTES), a process dependent on phosphorylated SF1. SOX9 also activates hTES, augmented by SF1, suggesting a mechanism for maintenance of SOX9 expression by auto-regulation. Analysis of mutant SRY, SF1 and SOX9 proteins encoded by thirteen separate 46,XY DSD gonadal dysgenesis individuals reveals a reduced ability to activate hTES.Conclusions/SignificanceWe demonstrate how three human sex-determining factors are likely to function during gonadal development around SOX9 as a hub gene, with different genetic causes of 46,XY DSD due a common failure to upregulate SOX9 transcription.

89 MALE-TO-FEMALE SEX REVERSAL IN WOLF DERIVED FROM SOMATIC CELL NUCLEAR TRANSFER WITH 78,XY KARYOTYPE

Normal sexual differentiation relies on a complex cascade of numerous genes, many of which have yet to be identified. Gene defects can cause disorders of sexual development with varying severity. Among them, SRY (sex-determining region on Y chromosome) genes are involved in the early steps of maleness determination. In human, mutations of the SRY gene have been diagnosed in up to 20% cases of females with XY karyotype. There have been a few instances of intersexuality such as true hermaphrodites or pseudo hermaphrodites, but no reports yet in canid of XY male-to-female sex reversal. Recently, we reported the cloning of endangered male gray wolves (Canis lupus) from somatic cells collected postmortem (Oh HJ et al. 2008 Theriogenology). In this study, the 3 wolves were delivered with normal karyotype (78,XY), but 1 wolf had female external genitalia such as a vulva and clitoris. For further diagnosis, we conducted macroscopic, radiologic, surgical, histological, and cytogenetic study. On gonadotropin-releasing hormone stimulation test, the blood serum testosterone concentration was low (<1 ng mL–1). Imaging diagnosis by radiography in the form of uterogram and by ultrasonography revealed a normal uterus and bilateral ovary-like structures located caudal to the kidney. During exploratory laparotomy, we found a normal uterus and bilateral ovary-like mass. Histopathological analysis showed the uterus and ovary to be normal, but no evidence of the presence of testicular tissue. The molecular analysis of the SRY genes with a direct DNA sequencing technique detected nucleotide changes more than one position in this affected animal compared with that of the control groups (cell donor and other female litter mates) although at a low rate. However, we did not yet analyze the nature of this mutation such as amino acid change, location within gene, protein function, and so on, so it will be needed further studies. These results indicate that this abnormal sex development of the studied wolf was probably caused by SRY gene mutations. Herein, we reported the case of a cloned wolf with normal ovaries and uterus having a 78,XY karyotype. Further studies are required to elucidate whether this mutation in the SRY gene could impair the normal function of the SRY protein. This study was financially supported by the Korean MEST, through KOSEF (grant # M10625030005-08N250300510) and the BK21 program for Veterinary Science, and SNU foundation(Benefactor; RNL BIO)/Hanwha L&C.

Y chromosome mosaicism and occurrence of gonadoblastoma in cases of Turner syndrome and amenorrhoea

In the present study, 73 cases with a clinical diagnosis of Turner syndrome, or with primary or secondary amenorrhoea without frank Turner phenotype, were evaluated for presence of low level Y chromosome mosaicism using molecular methods. Fluorescence in-situ hybridization for centromere and q arm of the Y chromosome and nested polymerase chain reaction for the sex determining region on Y (SRY) gene were performed in peripheral blood, buccal cells and gonadal biopsies. The overall frequency of Y chromosome mosaicism was found to be 18% (13/73 cases). Four cases (16%) of Turner syndrome had Y chromosome mosaicism, seven cases (28%) with primary amenorrhoea and two cases (9%) with secondary amenorrhoea had Y chromosome mosaicism. Histologically detectable gonadoblastoma was observed in one of seven cases (14%) that had Y chromosome mosaicism. This frequency is lower than that reported previously, underscoring the need for large prospective investigations to determine the frequency of Y chromosome mosaicism and occurrence of gonadoblastoma in cases of Turner syndrome and other forms of amenorrhoea.

A novel sex-determining region on Y ( SRY) nonsense mutation identified in a 45,X/47,XYY female

Objective: To determine whether an SRY mutation participated in the phenotypic outcome in the case of a 45,X/47,XYY female. Design: Analysis of genomic DNA for mutations in SRY. Setting: An academic teaching hospital. Patient(s): A family that included one phenotypic female with 45,X/47,XYY mosaicism. Intervention(s): Extraction of DNA, polymerase chain reaction analysis, nucleotide sequencing, and restriction enzyme analysis. Main Outcome Measure(s): Comparison of control and subject DNA sequences. Result(s): The patient demonstrated one nucleotide (thymine, T) deletion at position 422, leading to a frame-shift mutation. This mutation changes the codon for Tyr (TAT) to a stop codon (TAG) within the open reading frame just upstream of a conserved DNA-binding motif. Neither other mutations nor nucleotide mosaicisms were found in the remaining regions of the gene. This mutation was not present in the patient’s normal father. Conclusion(s): The mutant SRY may be assumed to induce a nonfunctional SRY-coded protein that lacks a DNA-binding motif. These results explain the phenotypic female and the gonadal dysgenesis in the 45,X/47,XYY sex-reversed offspring.

Absence of microdeletions in the Y chromosome in patients with a history of cryptorchidism and azoospermia or oligospermia

Objective: To determine if cryptorchidism is associated with microdeletions of interval 6 of the Y chromosome, we evaluated this locus in men with a history of cryptorchidism with and without azoospermia or oligospermia and in a control group. Design: Clinical study. Setting: Academic research environment. Patient(s): Men in whom surgical treatment of cryptorchidism had been performed in childhood and healthy control male subjects. Intervention(s): None. Main Outcome Measure(s): Genotyping of interval 6 of the Y chromosome. Result(s): Analysis of semen obtained from men treated for cryptorchidism in childhood showed azoospermia or oligospermia in 14 of 38 (37%) men. No microdeletions were identified with polymerase chain reaction amplification of 17 distinct sequence tagged sites located on the long arm of the Y chromosome and the sex determining region on Y ( SRY) gene. Conclusion(s): Microdeletions of interval 6 of the Y chromosome were not detected in either the formerly cryptorchid or in the healthy subjects. Although we cannot exclude the possibility of point mutations, we conclude that cryptorchidism or cryptorchidism associated with azoospermia or oligospermia is not due to microdeletions involving interval 6 of the Y chromosome.

A 47, XXY female

Klinefelter syndrome (47,XXY) with male phenotype is the most common sex chromosomal abnormality. It is believed that SRY (sex determining region on Y) is the major gene necessary to induce the undifferentiated bipotential gonadal primordium to develop as testis. Recently, several SRY-boxrelated (SOX) genes have been identified on autosomes. Mutations in the SRY or SOX gene have been implicated in sex reversal. We report an individual having 47,XXY chromosome constitution, normal SRY, SOX9, and ZFY genes and yet with a female phenotype. A 15-year-old phenotypic female has well developed breasts; prominent labioscrotal folds; an enlarged clitoris; feminine pubic hair distribution; urethra in the centre of the vestibule; a urogenital sinus 5 cm deep; a uterus; prepubertal in shape and size, palpable per rectum; and a cervix which could not be palpated. Ultrasonography of the abdomen revealed normal shape of urinary bladder with smooth and regular walls. Uterus was small in size, with normal shape and outline. Myometrium was homologous, cavity was empty, midline echo was normal. Laparoscopic assessment revealed a normal uterus. Right ovary was normal in size and shape with a cyst and a normal Fallopian tube. Left ovary was not seen as it was hidden beneath an epithelial fold. Chromosome analysis showed 47,XXY karyotype in all 100 metaphases analysed. Hormone profiles showed average female range of corticotrophin, T3, T4, thyrotrophin, and testosterone. Progesterone and prolactin were higher when compared with normal female levels. Histology of the right gonad showed features compatible with ovarian stroma. No RESEARCH LETTERS

Paternal somatic and germ-line mosaicism for a sex-determining region on Y (SRY) missense mutation leading to recurrent 46,XY sex reversal: Hines R.S.; Tho S.P.T.; Zhang Y.Y.; Plouffe L. Jr.; Hansen K.A.; Khan I.; McDonough P.G. USA Fertil Steril 1997 67/4 (675–679)

Paternal somatic and germ-line mosaicism for a sex-determining region on Y (SRY) missense mutation leading to recurrent 46,XY sex reversal: Hines R.S.; Tho S.P.T.; Zhang Y.Y.; Plouffe L. Jr.; Hansen K.A.; Khan I.; McDonough P.G. USA Fertil Steril 1997 67/4 (675–679)

Paternal somatic and germ-line mosaicism for a sex-determining region on Y (SRY) missense mutation leading to recurrent 46,XY sex reversal

Objective: To determine the etiology for recurrent 46,XY sex reversal in a family with two Swyer siblings. Design: Deoxyribonucleic acid (DNA) from peripheral lymphocytes and sperm were analyzed for duplication of the dosage sensitive sex locus (DSS) and for mutations in sex-determining region on Y (SRY). Setting: An academic teaching hospital. Patients: A family consisting of mother, father, and five phenotypic daughters, of which two were 46,XY sex-reversed females. Intervention: Deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR), Southern blotting, dosage densitometry, single-strand conformation polymorphism (SSCP), and sequencing. Main Outcome Measure: Comparison of control and subject DNA. Results: Deoxyribonucleic acid (DNA) analysis of SRY in genomic DNA from the 46,XY sexreversed siblings revealed identical missense mutations (T → G) in both sisters. Analysis of the SRY gene in paternal lymphocyte and sperm DNA revealed mosaicism for wild and mutant (T→ G) SRY sequences. SRY analysis of sperm DNA also demonstrated the same mosaicism for the T → G missense mutation. Conclusion: A postembryonic SRY mutation gave rise to paternal mosaicism for two distinct cell populations (SRY+/SRY-). The presence of a wild type SRY in the somatic cell line may account for a normal pattern of male sexual differentiation, whereas the presence of a mutated SRY in the germ line resulted in two 46,XY sex-reversed offspring. These results confirm a proposed mechanism for the condition of recurrent 46,XY sex-reversed females.

Sex determination and gonadogenesis: a transcription cascade of sex chromosome and autosome genes.

G onadal determination and differentiation are key events in the process of sex differentiation as the gonadal sex controls embryological differentiation of the accessory structures and later sexual maturation. The formation of a testis or ovary from the bipotential primordial gonad is regulated by the presence or absence of the Y chromosome encoded testis determining factor known as SRY (sex determining region on Y). SRY contains an 80 amino acid domain resembling the divergent class of the high mobility group (HMG) b ox that, in related proteins, binds to DNA and regulates gene transcription. Thus, SRY probably regulates directly or indirectly the transcription of a cascade of genes necessary for testicular determination and differentiation. If SRY is not present, as in XX females, an alternate genetic program executes and ovaries form. Proteins other than SRY are also required for proper gonadogenesis, some working independently, and others working either upstream or downstream of SRY. The importance of these proteins is clearly shown in the many human disorders of gonadal determination that are autosomal or Xlinked and therefore not due to defects in SRY. This review discusses the recent discovery of the testis determining switch, SRY, its possible mechanism of action and the evidence for several proteins with postulated roles in gonadogenesis revealed through work in both mice and humans. These proteins include anti-mullerian hormone, one of the Wilms’ tumor suppressor loci, WT-1, and the receptor tyrosine kinase c-kit and its ligand.