Genotipificación del gen RHD en ADN fetal libre en plasma de embarazadas RhD negativo / Genotyping of the RHD gene in free fetal DNA in plasma of RhD negative pregnant women

Objetivo: Determinar el grupo RhD fetal a través del estudio del gen RHD en ADN fetal que se encuentra libre en plasma de embarazadas RhD negativo. Método: Se analizó la presencia de los genes RHD, SRY y BGLO en ADNfl obtenido de plasma de 51 embarazadas RhD negativo no sensibilizadas, utilizando una qPCR. Los resultados del estudio genético del gen RHD se compararon con el estudio del grupo sanguíneo RhD realizado por método serológico en muestras de sangre de cordón, y los resultados del estudio del gen SRY fueron cotejados con el sexo fetal determinado por ecografía. Se calcularon la sensibilidad, la especificidad, los valores predictivos y la capacidad discriminativa del método estandarizado. Resultados: El gen RHD estaba presente en el 72,5% de las muestras y el gen SRY en el 55,5%, coincidiendo en un 100% con los resultados del grupo RhD detectado en sangre de cordón y con el sexo fetal confirmado por ecografía, respectivamente. Conclusiones: Fue posible deducir el grupo sanguíneo RhD del feto mediante el estudio del ADN fetal que se encuentra libre en el plasma de embarazadas con un método molecular no invasivo desarrollado y validado para este fin. Este test no invasivo puede ser utilizado para tomar la decisión de administrar inmunoglobulina anti-D solo a embarazadas RhD negativo que portan un feto RhD positivo.

Objective: To determine the fetal RhD group through the study of the RHD gene in fetal DNA found free in plasma of RhD negative pregnant women. Method: The presence of the RHD, SRY and BGLO genes in fetal DNA obtained from plasma of 51 non-sensitized RhD negative pregnant women was analyzed using qPCR. The results of the genetic study of the RHD gene were compared with the RhD blood group study performed by serological method in cord blood samples, and the results of the SRY gene study were compared with the fetal sex determined by ultrasound. Sensitivity, specificity, predictive values and discriminative capacity of the standardized method were calculated. Results: The RHD gene was present in 72.5% of the samples and the SRY gene in 55.5%, coinciding 100% with the results of the RhD group detected in cord blood, and with the fetal sex confirmed by ultrasound, respectively. Conclusions: It was possible to deduce the RhD blood group of the fetus through the study of fetal DNA found free in the plasma of pregnant women with a non-invasive molecular method developed and validated for this purpose. This non-invasive test can be used to make the decision to administer anti-D immunoglobulin only to RhD-negative pregnant women carrying an RhD-positive fetus.

A rapid and useful method for gender identification of grey red-backed voles / 中国比较医学杂志

Objective Grey red-backed voles (Myodes rufocanus) are agile, fierce and hard to catch, thus, it is difficult to judge their gender by external appearance, especially for the juvenile voles. Therefore, it may cause difficulties to their allocation and later breeding in laboratories. The aim of this paper is to establish a rapid, simple and accurate method for gender identification of grey red-backed voles. Methods Fresh hair follicles were taken from 6 adult male voles, 3 adult females and 14 4-week-old juvenile voles, 5 male and 5 female 9-week-old Wistar rats, and 5 male and 3 female 6-week-old BALB/c mice. The genomic DNA was extracted using Chelex-100 resin and the zinc-finger Y/X gene (ZFY/ZFX) and the gene of sex-determining region of the Y (SRY) chromosome were amplified by PCR, and a double PCR amplification method was established. Results The ZFY/ZFX gene and SRY gene were simultaneously amplified from the male voles, while only the ZFY/ZFX gene was amplified from the females. The gender of all 23 voles, 10 Wistar rats and 8 BALB/c mice were correctly identified with this method, and the PCR results were consistent with the phenotypic and autopsy results. Conclusions Using fresh hair follicles as experimental materials for gender identification of grey redbacked voles can alleviate shock and damage to the animals. The established double PCR amplification method is accurate, simple, rapid, and deserves to be used for gender identification of grey red-backed voles.

Highly Sensitive and Specific Detection of SRY Gene for Non-invasive Prenatal Diagnosis / 分析化学

By detecting SRY gene of cell-free fetal DNA ( cffDNA) in maternal peripheral blood, the sex of fetuses was determined, the risks of sex-linked genetic disorders were assessed and the birth rate of sick fetuses was decreased. A method of real-time polymerase chain reaction ( PCR) coupled with invader assay was established to detect SRY gene. This method possessed the advantages such as high sensitivity, high specificity and non-contaminated with closed tube detection. Under the optimized reaction conditions such as 250 nmol/L detection probes, 7. 5 U FEN1 enzyme, 0. 5 U Taq polymerase and 67℃ of annealing temperature in pre-amplification, the simulated samples as low as 4% ( 4 copies/μL ) were detected and two clinical samples with the gestation age of 9 weeks and 10 weeks were successfully detected. The detection results showed that this method could be used to detect SRY gene of cffDNA in maternal peripheral blood, providing an effective technique for clinical non-invasive prenatal diagnosis based on SRY gene.

Highly Sensitive and Specific Detection of SRY Gene for Non-invasive Prenatal Diagnosis / 分析化学

By detecting SRY gene of cell-free fetal DNA ( cffDNA) in maternal peripheral blood, the sex of fetuses was determined, the risks of sex-linked genetic disorders were assessed and the birth rate of sick fetuses was decreased. A method of real-time polymerase chain reaction ( PCR) coupled with invader assay was established to detect SRY gene. This method possessed the advantages such as high sensitivity, high specificity and non-contaminated with closed tube detection. Under the optimized reaction conditions such as 250 nmol/L detection probes, 7. 5 U FEN1 enzyme, 0. 5 U Taq polymerase and 67℃ of annealing temperature in pre-amplification, the simulated samples as low as 4% ( 4 copies/μL ) were detected and two clinical samples with the gestation age of 9 weeks and 10 weeks were successfully detected. The detection results showed that this method could be used to detect SRY gene of cffDNA in maternal peripheral blood, providing an effective technique for clinical non-invasive prenatal diagnosis based on SRY gene.

A Case of Molecular Analysis of XX Male Syndrome / 대한법의학회지

Sex typing may become the start point in investigations that are usually performed through amelogenin typing. In cases involving genotype-phenotype discrepancy, amelogenin typing could yield misleading results. The rare XX male syndrome is characterized by a phenotypic male with a 46, XX female karyotype. In this point, this case report would help understand the importance of genotype-phenotype discrepancy.

A novel mutation of SRY gene identified in a 46,XY complete gonadal dysgenesis patient / 中华内分泌代谢杂志

The clinical and genetic characteristics in a patient with 46,XY complete gonadal dysgenesis was investigated. Clinical features and laboratory data were collected from the patient and the family. The exon of SRY gene was amplified by PCR and sequenced. The patient presented with primary amenorrhea, nonambiguous female external genitalia, slight breast development, and no axillary hair or pubic hair. The female internal reproductive organs consisted of uterus and streaks of ovarian tissue. Howerver, the chromosome karyotype was 46,XY. A missense mutation of A66T in SRY gene was identified, which was not previously reported. The novel SRY mutation caused the sex reversal in this 46,XY female patient.

Mechanism of recombinant human bone morphogenetic protein-2 in repairing hematopoietic injury in mice exposed to γ-rays / 中华放射医学与防护杂志

Objective To investigate the mechanism of recombinant human bone morphogenetic protein-2(rhBMP-2)in repairing hematopoietic injury in mice irradiated with γ-ray.To prepare SRY gene probe and study the effect of rhBMP-2 in repairing hematopoietic injury in mice by in situ hybridization.Methods Twenty-two BALB/c female mice were randomly divided into the irradiated group and BMP treated group,respectively.Bone marrow cells of normal male mice were transplanted into 22 female mice post-irradiation to 8.5 Gy of 60 Co γ rays.The left femurs of the survived female mice were re-irradiated with 9 Gy 14 days later.Mice in BMP treated group were given rhBMP-2 20 mg/kg while those in control group were treated with 0.9% saline by intraperitoneal injection every day for 6 days.These mice were killed 14 days later and paraffin sections of femurs were made.The SRY gene was detected with in situ hybridization.Results There were more positive blots in the left femurs of the mice in irradiated group than those in BMP treated group(T=155.0,P＜0.05).The number of positive blots between the left femurs of the mice in irradiated group and the right femurs of the mice in two groups was not significantly different(T=92.0,78.5,P＞0.05).The number of positive blots in the left femurs of the mice in BMPtreated group was significantly less than those in the right femurs of the mice in two groups(T=155.0,55.0,P＜0.05).Conclusions No donor cell of male mice was detected in the left femurs of BMP treated group,suggesting that rhBMP-2 promoted the restoration of residuary bone marrow cells.Thus,rhBMP-2 promotes the proliferation or differentiation of residuary mesenchymal stem cells,improves hematopoietic microenvironment and accelerates the hematopoietic restoration.

Identification of Y Chromosomal Material in Turner Syndrome by Fluorescence In Situ Hybridisation (FISH)

Turner syndrome is one of the most common chromosomal abnormalities affecting newborn females. More than half of patients with Turner syndrome have a 45X karyotype. The rest of the patients may have structurally abnormal sex chromosomes or are mosaics with normal or abnormal sex chromosomes. Mosaicism with a second X sex chromosome is not usually of clinical significance. However, Turner syndrome patients having a second Y chromosome or Y chromosomal material are at risk of developing gonadoblastoma later in life. The aim of this study is to compare the results of conventional (karyotyping) and molecular cytogenetics (FISH), and discuss the advantages and limitations in the diagnosis of Turner syndrome. We also aim to compare the degree of mosaicism identified using conventional cytogenetics and FISH techniques. Conventional cytogenetics and FISH analyses were performed on eight peripheral blood samples of patients with Turner syndrome collected between 2004 and 2006. From this study, two out of eight patients with Turner syndrome were found to have the sex determining region on the Y chromosome (SRY) gene by FISH analysis. Our results showed that the rate of detection of mosaic cases in Turner syndrome was also increased to 88% after using the FISH technique. We concluded that FISH is more superior to conventional cytogenetics in the detection of the Y chromosomal material. FISH is also a quick and cost effective method in diagnosing Turner syndrome and assessing the degree of mosaicism.

A Case of a 46,XX Male with SRY Gene

46,XX male is a rare sex constitution characterized by the development of bilateral testis in persons who lack a Y chromosome. Manifestations of 46,XX males are usually hypogonadism, gynecomastia, azoospermia, and hyalinations of seminiferous tubules. The incidence of XX male reversal is approximately 1 in 20,000 male neonates. The SRYgene is located at the short arm of the Y chromosome(Yp11.31) and codes for testis determining factor in humans. Here, the patient, who presented with a normal male phenotype, was referred for azoospermia. Conventional cytogenetic analysis showed a 46,XX karyotype. Quantitative fluorescent polymerase chain reaction(QF-PCR) and Multiplex PCR studies identified SRY gene. And, Fluorescence In Situ Hybridization(FISH) confirmed the SRY gene on the distal short arm of chromosome X. We identified the SRY gene on the distal short arm of chromosome X by molecular cytogenetic and molecular analyses. Therefore, molecular-cytogenetics and molecular studies were proved to be clinically useful adjunctive tool to conventional prenatal cytogenetic analysis.

Analysis of SRY Gene in 6 Cases With Sexual Abnormality / 医学研究杂志

Objective TO Provide information for clinical diagnosis and study the mechanism of sexual abnormality . Methods 6 cases of sexual abnormality were detected with PCR amplification and DNA sequencing techniques.ResultsSRY gene was positive in 45,XO male and 46,XY female whose DNA sequence of conserved region had no mutation.SRY gene was negative in 46,Xxmale.Three46,XY males with sexual abnormality showed SRY positive.Conclusions The sexual abnormality of 45,Xomale was caused by SRY positive.Conclusions The sexual abnormality of 45,XOmale was caused by SRY gene translocation .Sexual reverse infemale was caused by gene conseved region mutation but in male it might be caused by sexual related gene mutation on chromasome.

Congenital bilateral anorchia: hormonal, molecular and imaging study of a case

The aetiology of congenital bilateral anorchia is unknown. For many years there was speculation of an association between genetic factors and anorchia. We performed different tests in an anorchid boy, 2.5 years old, presented to us with micropenis and absence of both testes, in order to determine any possible factors contributing to the anorchia. Physical examination and hormonal, imaging, chromosomal, and molecular analyses of this case were performed. The basal FSH and LH levels were increased, and their increase in response to gonadotrophin-releasing hormone test was prolonged, while testosterone levels failed to increase after hCG administration. Ultrasonography of the pelvis and magnetic resonance of the abdomen were performed and failed to show any testicular tissue. Lastly, surgical exploration confirmed the absence of testicular structure. Chromosomal analysis revealed a normal male karyotype and molecular analysis did not reveal mutations or polymorphisms in the open reading frame of the SRY gene. Diagnostically, the lack of testosterone response to hCG stimulation is the hormonal hallmark of bilateral congenital anorchia. In addition, according to our case and previous studies, there is lack of association between genetic factors necessary for correct testicular descent and anorchia.

An infertile 45,X male carrying an unbalanced(Y,13) translocation:A clinical cytogenetic and molecular study / 医学研究生学报

Objective: To report a case of azoospermia with a karyotype of 45,X,der(Y)t(Y;13)(q11.2;q12),-13,accompanied with slight bilateral gynecomastia and multiple nodules.Methods: The karyotype was identified by karyotyping and FISH,and the breakpoints of the Y chromosome and the copy number of the BRCA2 gene in 13q12 determined by PCR-STS and DNA polymorphic analysis.The testis and nodule tissues of the patient were obtained for biopsy.Results: FISH confirmed SRY and centromere of the Y chromosome on the questionable 13 chromosome and the karyotype to be 45,X,der(Y)t(Y;13)(q11.1;q12),-13.ish der(Y)(SRY+,DYZ3+,wcp13+).PCR-STS showed the deletion of regions AZFa,b and C,with a breakpoint located inYq11.1 below sY82.No deletion of the BRCA2 gene was observed.The patient was diagnosed with Sertoli cell-only syndrome by testicular biopsy and with angiolipomata by pathological examination of the nodule tissue.Conclusion: The patient's phenotype of complete masculinization could be attributed to presence of the SRY gene,and his azoospermia with small testis to the absence of a fragment from Yq11.1 to Yqter.However,the molecular mechanism of angiolipoma remains unknown.

Detection of Y Chromosome-specific Sequences in Patients with Turner Syndrome / 대한산부인과학회잡지

Existence of Y derived chromosome in Turner patients is significant due to the risk of gonadoblastoma development, but cytogenetic analysis may fail to detect low levels of Y chromosomal materials. Recent studies using PCR based methods showed higher sensitivity to detect Y-specific sequences, in patients who were Y chromosome-negative cytogenetically. In this study PCR was performed on 44 Turner patients with no Y chromosome by cytogenetic analysis to detect the SRY, AMELY, ZFY, and DYZ1 sequences. Of seven patients whose karyotypes were 45,X/46,X,+mar, three patients were positive for SRY, ZFY, and AMELY. DYZ1 sequences was negative in them. And any of SRY, ZFY, AMELY, and DYZ1 sequences was detected in the remaining 37 patients. This result shows that PCR analysis for Y-specific sequences in Turner patients, especially in patients who have marker chromosome is a significant effort.

When Can We Identify Fetal Male Gene By Using Maternal Plasma DNA? / 대한산부인과학회잡지

OBJECTIVE: To know when we can identify fetal Y chromosome SRY gene by using fetal DNA in maternal plasma. METHODS: DNA from maternal plasma of 62 pregnant women (48: inpatients, 14: outpatients) underwent a sensitive Y-PCR assay to identify SRY gene of Y chromosome. RESULTS: Of the patients, fetus-derived Y sequences were detected in 37 (88.1%) of the 42 maternal plasma samples from women bearing male fetuses. One of the 20 women bearing female fetuses had positive result from plasma DNA. Seventh gestational week was the earliest gestation of gender identification. CONCLUSION: We could identify fetal gender using fetal DNA in maternal plasma (sensitivity 88.1%). The earlist to detect was 7th gestational week.

45,X / 47,XYY Mosaic Turner Syndrome / 대한산부인과학회잡지

45,X/47,XYY mosaicism is a rare sex chromosomal disorder with clinical information limited to 25 cases in the literature. We report an unusual mosaic Turner syndrome case in a 35-year old Korean woman with a phenotypic female, primary amenorrhea, short stature, immature secondary sexual characteristics. Cytogenetic analysis including G- and Q-banding revealed 45,X/47,XYY mosaicism, and SRY gene was demonstrated by polymerase chain reaction(PCR). Prophylactic bilateral gonadectomy was performed because the presence of Y-chromosomal sequences in Turner stigmata may predispose this patient to gonadoblastoma formation.

Clinical Characteristics in the 45XO/46XY Mosaicism and 45XO with SRY Gene Positive Patients / 대한비뇨기과학회지

PURPOSE: We investigated the clinical characteristics and relationship between chromosome and its phenotypic expression in patients with 45 XO/46XY mosaicism or 45 XO with SRY gene. MATERIALS AND METHODS: 11 patients with 45XO/46XY chromosomal abnormality and 4 patients with 45XO with SRY positive reaction admitted from 1990 to 1996 were evaluated. Patients were grouped according to chromosome and gonadal expression. Group A consisted of patients with 45XO/46XY chromosome and unilateral streak gonad, group B patients with 45XO chromosome, SRY positive reaction and unilateral streak gonad and group C patients with 45XO/46XY chromosome and bilateral streak gonads. RESULTS: Of the total 15 patients, the number of patients in group A, B, and C were 8, 4, and 3, respectively. SRY gene was positive in all group A and B patients but only one patient was positive in group C. Of the 8 patients in group A, 5 patients had a high XY mosaicism ratio compared to XO whereas an equal ratio was observed in the remaining 3 patients. Of the 4 male penotype patients only 1 patient had a high XY mosaicism ratio compared to XO while 3 patients displayed an equal ratio. There was no difference in associated anomaly and the degree of severity of ambiguity according to the mosaicism ratio in all patients. CONCLUSIONS: There was no definite correlation between the mosaicism ratio and phenotypic expression. Presence of SRY gene in 45XO patients may suggest MGD(mixed gonadal dysgenesis) and therefore, the evaluation SRY gene could be useful in the diagnosis of 45XO patients with ambiguous genitalia.

Molecular and Cytogenetic Findings in 46,XX Males

This paper reports 3 cases with 46,XX sex reversed male. Three 46,XX hypogonadal subjects showed complete sex reversal and had normal phallus and azoospermia. We studied them under clinical, cytogenetic and molecular aspects to find out the origin of the sex reversal. Patients had markedly elevated serum follicle-stimulating hormone (FSH) and lutenizing hormone (LH) and decreased or normal range of serum testosterone. The testicular volumes were small (3-8ml). Testicular biopsy showed Leydig cell hyperplasia and atrophy of seminiferous tubules. We obtained the results of normal 46,XX and XY dual fluorescent in situ hybridization (FISH) which could rule out the presence of Y chromosome mosaicism. By using polymerase chain reaction (PCR), we amplified short arm (SRY, PABY, ZFY and DYS14), centromere (DYZ3), and heterochromatin (DYZ1) region of the Y chromosome. PCR amplification of DNA from these patients showed the presence of the sex-determining region of the Y chromosome (SRY) but didn't show the centromere and heterochromatin region sequence. The SRY gene was detected in all the three patients. Amplification patterns of the other regions were different in these patients; one had four amplified loci (PABY+, SRY+, ZFY+, DYS14+), another had two loci (SRY+, ZFY+) and the other had two loci (PABY+, SRY+). We have found that each patient's translocation elements had different breakpoints at upstream and downstream of the SRY gene region. We conclude that the testicular development in 46,XX male patients were due to insertion or translocation of SRY gene into X chromosome or autosomes.

Analysis of SRY Gene in Korean Patients with Swyer Syndrome and their Family Members / 대한산부인과학회잡지

Individuals affected with Swyer syndrome are phenotypic females with 46, XY karyotype, sexual infantilism, mullerina derivatives, and bilateral streak gonads that may undergo neoplastic transformation. The pathogenesis of this syndrome is uncertain, but may be related to a defect in the regulation or expression of the testicular determining factor which is believed to be located on the short arm of the Y chromosome. Recently, a region termed "SRY", a single copy gene of the Y chromosome was identified as belonging to a testis-determining gene. This gene is Y-specific, highly conserved among mammals, and transcribed only in testis. The predicted amino acid sequence of SRY shares homology with DNA-binding domains of transcription factors such as chromatinassociated, nonhistone proteins HMG 1 and HMG 2. Hence, it was thought that there may be some change in SRY gene of the patients with Swyer syndrome. And it was reported in some cases that there was deletion or mutation in the gene, but no abnormality of SRY gene was observed in other cases. So, it is a new approach to understand the mechanism of the human sexual differentiation to investigate this syndrome in terms of DNA sequence of SRY gene. To verify the presence or absence of SRY, or the change in SRY, we performed polymerase chain reaction and DNA sequencing of the conserved region of SRY gene from four patients with Swyer syndrome and their family members. The results are as follows. 1) Four patients with Swyer syndrome, their father, and two normal male control were positive whereas two female control were negative for the band that represents the coding sequence of SRY. 2) The DNA sequences of SRY gene from four patients with Swyer syndrome, their father, and two normal male control were the same, and there was no deletion or mutation in the gene. In conclusion, there may be complex sex determining cascade including other genes not only on the Y chromosome, but also on the X chromosome or even autosome in human sexual differentiation.

SRY Gene Evaluation in Patients with the Disorders of Sexual Differentiation / 대한비뇨기과학회지

The disorders of sexual differentiation occurred due to the incompatibility of chromosomal sex, gonadal sex and phenotypic sex. A gene within Y chromosome such as SRY gene has been searched to explain this phenomenon. We report cases of defective sexual differentiation, where it is difficult to diagnose with Giemsa stain of Y chromosome alone but SRY gene evaluation was helpful in the diagnosis and treatment of these cases. Genomic DNA from WBC was extracted. XES 10 and XES 11 were used as primers in separately SRY gene by electrophoresis. A positive SRY gene facilitated in confirming the diagnosis of the following cases: Klinefelter`s syndrome with a positive SRY gene originally diagnosed as 46 XX male, Klinefelter`s syndrome with 46XX,a positive SRY gene that was thought to be chordee without hypospadias. Turner`s syndrome that was difficult to be diagnosed due to 46XY, a positive SRY gene, however, SRY gene detection was helpful to detect germ cell tumor development early. 46XX hermaphroditism without SRY gene was diagnosed as true intersex after pathologic examination. Two cases of 46XY hermaphroditism with SRY gene were diagnosed finally as 46 XY true intersex and mixed gonadal dysgenesis each other. Congenital adrenal hyperplasia and androgen receptor defect were confirmed by traditional methods such as hormonal tests and radiologic findings. SRY gene evaluation facilitated in identifying the pathophysiology of many defective sexual differentiations, however, this alone had a limit to explain all these cases. So future research into genes in the autosome, sex chromosome and Z protein will help in the diagnosis and treatment of patients with the disorders of sexual differentiation.