Y-chromosome identification by PCR and gonadal histopathology in Turner's syndrome without overt Y-mosaicism

Recognition of the Y chromosome in Turner syndrome using peripheral blood or oral mucosa tissue

PURPOSE

Turner syndrome is defined as total or partial loss of the second sex chromosome in a phenotypically female patient. Due to the possibility of hidden mosaicism of fragments of the Y chromosome and development of gonadoblastoma, we evaluated the presence of such fragments in 2 tissues with different embryonic origins, peripheral blood lymphocytes (mesoderm), and oral mucosal cells (ectoderm) using multiplex polymerase chain reaction.

METHODS

DNA samples were collected from 109 patients, and primers for the SRY, TSPY, and AMELX genes were used.

RESULTS

We found 14 patients (12.8%) with positive molecular markers for the Y chromosome. The study of tissues of different embryological origin showed the same degree of agreement, sensitivity, and specificity.

CONCLUSION

Oral mucosa cells have a simpler method of collection that is less invasive and requires less time for DNA extraction at a lower cost.

A clinical algorithm to diagnose differences of sex development

The diagnosis and management of children born with ambiguous genitalia is challenging for clinicians. Such differences of sex development (DSDs) are congenital conditions in which chromosomal, gonadal, or anatomical sex is atypical. The aetiology of DSDs is very heterogenous and a precise diagnosis is essential for management of genetic, endocrine, surgical, reproductive, and psychosocial issues. In this Review, we outline a step-by-step approach, compiled in a diagnostic algorithm, for the clinical assessment and molecular diagnosis of a patient with ambiguity of the external genitalia on initial presentation. We appraise established and emerging technologies and their effect on diagnosis, and discuss current controversies.

Does having Turner syndrome affect quality of life in Brazilian women compared to common population?

OBJECTIVES

We aimed to measure the quality of life (QoL) of patients with Turner syndrome (PTS) and determine the extent to which their clinical or laboratory alterations influence QoL compared to reference women (RW) of the same age range.

SUBJECTS AND METHODS

From Dec-2013 to Dec-2014, 90 participants were recruited. They were 18 years and older: 48 with Turner syndrome (TS) (PTS) and 42 without (RW). Recruited subjects completed the Portuguese version of Short Form 36 (SF-36) questionnaire, and blood was drawn to measure LH, FSH, oestradiol (E2), progesterone (P4), SHBG, and SDHEA (by ECLIA) and testosterone (by LC MS/MS).

RESULTS

Age and schooling were similar between groups. The most common occupations for PTS were health worker, administration and education, and health worker or cashier for RW. Most participants were Catholic or Evangelical. Eighty-one percent (39/48) of cases used Hormonal Replacement Therapy (HRT), mostly transdermal (23/39). RW and PTS scored similarly on the SF-36 questionnaire. RW had higher oestradiol (p = 0,01), lower FSH (p = 0,01) and higher testosterone (p = 0,01) than PTS. Concentrations of P4, LH, SHBG or SDHEA were similar. Significant associations were found among QoL and hormones (E2 with Vitality and LH with Physical Role) only in the PTS group.

CONCLUSIONS

PTS do not consider that TS affects their QoL as measured by domains on the SF-36. Oestradiol was related with QoL, emphasising the importance of HRT.

Detection of the SRY gene in patients with Turner Syndrome

BACKGROUND

If turner syndrome (TS) patients have a Y-containing cell line, they have an increased risk for gonadal tumors. TS patients are therefore screened for Y-chromosome and Y-specific sequences, such as SRY, DYZ1, DYZ3, DYS132, ZFY, TSPY, etc. In addition, since the dysgenetic gonad may include the stroma and granulosa/sertoli cells, which produce androgens, virilization can seen in girls with Y-chromosomal material. Prophylactic gonadectomy may therefore be required for optimal management in such patients. Our aim is to discuss our observations in the follow-up of TS patients.

METHODS

SRY was investigated in 71 out of 85 TS cases (aged 3 months-27 years) between 2005 and 2017. Fluorescent in situ hybridization (FISH) was used until 2014, after which SRY analysis was performed using the polymerase chain reaction (PCR) method. SRY analysis was performed a second time using PCR in 25 cases previously investigated with FISH.

RESULTS

We identified no positive cases. No pathological findings in terms of virilization, clitoromegaly, or posterior labial adhesions were also determined in our TS cases. Further studies were not required since no pathological findings also were detected at ultrasonography.

CONCLUSION

If Y-chromosome material has not been detected by conventional cytogenetic methods in TS patients with masculine features, further techniques should be applied to prevent the risk of invasive tumors, such as multiple sequences beside the Y centromere. This approach will prevent overtreatment.

Gonadal malignancy risk and prophylactic gonadectomy in disorders of sexual development

Disorders of sex development (DSD) are a generic definition including any problem noted at birth where the genitalia are atypical in relation to the chromosomes or gonads. The most important clinical problems in DSD comprise physical and psychological disturbances and the risk of gonadal tumor development. Germ cell tumor risk is lowest (<5%) in patients with defects in androgene action or synthesis (such as complete androgen insensitivity syndrome, 5α-reductase deficiency), whereas the highest risk (15%-60%) is observed in 46,XY gonadal dysgenesis. The presence of Y chromosomal material in the karyotype increases the risk for the development of gonadal tumors. The reported age of tumor development varies based on the etiology of DSD (gonadal dysgenesis, androgen insensitivity syndrome, androgen synthesis defects, mixed gonadal dysgenesis, etc.). In the past, early gonadectomy was recommended for all cases of 46,XY DSD, however, according to current approaches, gonadal tumor risk is predicted based on the molecular diagnosis and the timing of the gonadectomy depends on the result of molecular analysis. Until now, optimal protocol in the management of DSD is still controversial. In addition to that, safe and well-accepted guidelines are needed. There is limited number of prospective studies on timing of a gonadectomy in childhood and adolescence. Therefore, evidence-based data on timing and indications of gonadectomy in patients with DSD are needed. In this review, recent data regarding gonadal malignancy risk in DSD and recommendations on timing of gonadectomy are presented.

Y chromosome in Turner syndrome: detection of hidden mosaicism and the report of a rare X;Y translocation case

Turner syndrome (TS) is a common genetic disorder in females associated with the absence of complete or parts of a second sex chromosome. In 5-12% of patients, mosaicism for a cell line with a normal or structurally abnormal Y chromosome is identified. The presence of Y-chromosome material is of medical importance because it results in an increased risk of developing gonadal tumours and virilisation. Molecular study and fluorescence in situ hybridisation approaches were used to study 74 Brazilian TS patients in order to determine the frequency of hidden Y-chromosome mosaicism, and to infer the potential risk of developing malignancies. Additionally, we describe one TS girl with a very uncommon karyotype 46,X,der(X)t(X;Y)(p22.3?2;q11.23) comprising a partial monosomy of Xp22.3?2 together with a partial monosomy of Yq11.23. The presence of cryptic Y-chromosome-specific sequences was detected in 2.7% of the cases. All patients with Y-chromosome-positive sequences showed normal female genitalia with no signs of virilisation. Indeed, the clinical data from Y-chromosome-positive patients was very similar to those with Y-negative results. Therefore, we recommend that the search for hidden Y-chromosome mosaicism should be carried out in all TS cases and not be limited to virilised patients or carriers of a specific karyotype.

Increased risk of gonadal malignancy and prophylactic gonadectomy: a study of 102 phenotypic female patients with Y chromosome or Y-derived sequences

STUDY QUESTION

What is the optimal protocol of management for phenotypic female patients with Y chromosome or Y-derived sequences, in particular for adult patients?

SUMMARY ANSWER

Immediate gonadectomy, long-term hormone therapy and psychological care are suggested to be the optimal management for older phenotypic female patients with Y chromosome or Y-derived sequences.

WHAT IS KNOWN ALREADY

Phenotypic female patients with Y chromosome or Y-derived sequences are at increasing risk of developing gonadal tumors with age. Early diagnosis and safe guidelines of management for these patients are needed.

STUDY DESIGN, SIZE, DURATION

One hundred and two phenotypic women with Y chromosome or Y-derived sequences were included in a straightforward, retrospective-observational study conducted over a period of 26 years from January 1985 to November 2010.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Patients aged 16-34 years presenting to our Academic Department of Gynecology with symptoms of disorders of sex development were subjected to history taking, hormonal evaluation, conventional cytogenetic analysis, PCR, histopathology and immunohistochemistry. Features of the gonads were examined and the outcome of prophylactic gonadectomy evaluated.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the patients recruited in our study, 48 patients (47.1%) were diagnosed with complete/partial androgen insensitivity syndrome (CAIS/PAIS) (46XY), 33 cases (32.4%) with gonadal dysgenesis (46XY) and the remaining subjects (20.1%) with mixed gonadal dysgenesis (with sex chromosome structural abnormalities). The total incidence of malignancy was 17.6%. Seventeen patients (16.7%) had gonadoblastoma, while one patient (1.0%) with gonadal dysgenesis had dysgerminoma. Gonadoblastoma were observed in 2/21 patients with sex chromosome structural abnormalities (9.5%), 3/33 patients with gonadal dysgenesis (9.1%), 9/30 patients with CAIS (30.0%) and 3/18 patients with PAIS (16.7%).

LIMITATIONS, REASONS FOR CAUTION

Selection bias in this cohort study may affect data interpretation due to the low incidence of disorders of sex development in the general population.

WIDER IMPLICATIONS OF THE FINDINGS

The risk for malignant transformation may occur in early life and highly increase with age in patients with Y chromosome or Y-derived sequences. Optimal timing of gonadectomy should be decided by multiple factors including the subgroup of disorder, age and degree of patient's maturity. In addition, gonadal biopsy is suggested when the disease is diagnosed and any evidence of premalignancy warranties gonadectomy.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Key Scientific Research Project (2013CB967404), Natural Science Funds of Zhejiang Province (Y13H04005), Zhejiang Qianjiang talent plan (2013R10027), the Fundamental Research Funds for the Central Universities and Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period (2012BAI32B04). The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER None.

State of the art review in gonadal dysgenesis: challenges in diagnosis and management

Gonadal dysgenesis, a condition in which gonadal development is interrupted leading to gonadal dysfunction, is a unique subset of disorders of sexual development (DSD) that encompasses a wide spectrum of phenotypes ranging from normally virilized males to slightly undervirilized males, ambiguous phenotype, and normal phenotypic females. It presents specific challenges in diagnostic work-up and management. In XY gonadal dysgenesis, the presence of a Y chromosome or Y-chromosome material renders the patient at increased risk for developing gonadal malignancy. No universally accepted guidelines exist for identifying the risk of developing a malignancy or for determining either the timing or necessity of performing a gonadectomy in patients with XY gonadal dysgenesis. Our goal was to evaluate the literature and develop evidence-based medicine guidelines with respect to the diagnostic work-up and management of patients with XY gonadal dysgenesis. We reviewed the published literature and used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) system when appropriate to grade the evidence and to provide recommendations for the diagnostic work-up, malignancy risk stratification, timing or necessity of gonadectomy, role of gonadal biopsy, and ethical considerations for performing a gonadectomy. Individualized health care is needed for patients with XY gonadal dysgenesis, and the decisions regarding gonadectomy should be tailored to each patient based on the underlying diagnosis and risk of malignancy. Our recommendations, based on the evidence available, add an important component to the diagnostic and management armament of physicians who treat patients with these conditions.

Hidden Y Chromosome Mosaicism in 48 Egyptian Patients with Turner’s Syndrome

Background. The presence of Y chromosome material in Turner's syndrome (TS) patients is a risk factor for the development of gonadoblastoma. Although conventional cytogenetic analysis is the definitive diagnosis of TS, low level Y chromosome mosaicism may be missed. Molecular analysis has demonstrated a higher proportion of mosaicism, but there is controversy regarding the prevalence of Y chromosome-derived material in those patients. Aim and Methods. This study was conducted to investigate the prevalence of hidden Y chromosome mosaicism in 48 TS Egyptian patients using polymerase chain reaction (PCR) for molecular DNA analysis of SRY gene and compare our results with those in the literature. Results. None of TS patients had a cytogenetically obvious Y chromosome; Y chromosome material was detected only at molecular analysis. SRY gene was found in 9 TS patients (18.75%) with the classical 45,X karyotype, whereas all other patients were SRY negative. Conclusion. Cytogenetically undetected Y chromosome mosaicism is common in TS patients; these data reinforce the need for adequate diagnosis of Y chromosome material in those patients. Molecular screening for Y chromosome-derived DNA should be routinely carried out in all TS patients.

Molecular detection of cryptic Y-chromosomal material in patients with Turner syndrome

A systematic search for a hidden Y-chromosome mosaicism, in Turner syndrome (TS) patients is justified by the evaluation of the risk of development of germ cell tumors. In this study, we analyzed cryptic Y-chromosome derivatives by polymerase chain reaction (PCR) coupled with fluorescence in situ hybridization (FISH) using Y-specific sequences in patients with TS, and validated this methodology. Unrelated patients with TS (n=32) of Mexican mestizo ethnic origin were diagnosed using cytogenetic analysis. Clinical assessment, endocrine evaluation, karyotyping, FISH and PCR analysis of the Y-chromosomal loci were performed. We found that 9.4% (3 out of 32) patients with TS had Y-chromosome material. Two patients showed Y-chromosome by conventional cytogenetics. One patient had no Y-chromosome by initial karyotyping (45, X) but was positive by lymphocyte PCR DNA analysis of the Y-sequence-specific sex-determining region Y (SRY) gene. Our results suggest that the detection of the Y-chromosome material using sensitive methods, such as PCR coupled with FISH, should be carried out in all patients with TS and should not be limited to TS patients with cytogenetically identifiable Y-chromosome and/or virilization.

Intersections of Epigenetics, Twinning and Developmental Asymmetries: Insights Into Monogenic and Complex Diseases and a Role for 3D Facial Analysis

For decades the relationships of twinning and alterations in body patterning, such as laterality and asymmetry, have been investigated. However, the tools to define and quantify these relationships have been limited and the majority of these studies have relied on associations with subjectively defined phenotypes. The emerging technologies of 3-dimensional (3D) facial scanning and geometric morphometrics are providing the means to establish objective criteria, including measures of asymmetry, which can be used for phenotypic classification and investigations. Additionally, advances in molecular epigenetics provide new opportunities for novel investigations of mechanisms central to early developmental processes, twinning and related phenotypes. We review the evidence for overlapping etiologies of twinning, asymmetry and selected monogenic and complex diseases, and we suggest that the combination of epigenetic investigations with detailed and objective phenotyping, utilizing 3D facial analysis tools, can reveal insights into the genesis of these phenomena.

Ovarian hilus cell hyperplasia as the cause of virilization in 45,X Turner's syndrome

OBJECTIVE

To describe a rare case of 45,X Turner's syndrome with elevated T and clitoromegaly caused by ovarian hilus cell hyperplasia.

DESIGN

Case report.

SETTING

Tertiary care pediatric hospital.

PATIENT(S)

An 11-and-a-half-year-old girl with 45,X karyotype showed signs of accelerated growth and clitoromegaly and was found to have elevated serum T. Fluorescence in situ hybridization was used to confirm her karyotype as monosomy X and absence of the SRY gene. Elevated gonadotropins indicated absence of ovarian function.

INTERVENTION(S)

Laparoscopic bilateral gonadectomy.

MAIN OUTCOME MEASURE(S)

Serum T level.

RESULT(S)

Pathology showed ovarian hilus cell hyperplasia within the removed gonads. Serum T levels returned to normal after gonadectomy.

CONCLUSION(S)

Ovarian hilus cell hyperplasia is an extremely rare cause of virilization in Turner's syndrome. Gonadectomy should be considered for patients with confirmed 45,X karyotype who exhibit virilization.

OCT4 gonadal gene expression related to the presence of Y-chromosome sequences in Turner syndrome

To show that in the dysgenetic gonads of 104 Turner syndrome patients no significant difference was found regarding the expression of the genes DAX1, FOG2, GATA4, OCT4, SF1, SRY, TSPY, WT1, and STRA8 compared with controls, except for genes OCT4, SRY, and TSPY in both gonads of a patient whose chromosomal constitution was 45,X/45,X,add(15)(p11). The expression analysis of genes OCT4, SRY, and TSPY in the dysgenetic gonads of Turner syndrome patients may allow introducing modifications in the microenvironment that could contributed to a malignant transformation process.

Y chromosome in Turner syndrome: review of the literature

Turner syndrome (TS) is one of the most common types of aneuploidy among humans, and is present in 1:2000 newborns with female phenotype. Cytogenetically, the syndrome is characterized by sex chromosome monosomy (45,X), which is present in 50-60% of the cases. The other cases present mosaicism, with a 45,X cell line accompanied by one or more other cell lines with a complete or structurally abnormal X or Y chromosome. The presence of Y-chromosome material in patients with dysgenetic gonads increases the risk of gonadal tumors, especially gonadoblastoma. The greatest concern is the high risk of developing gonadoblastoma or other tumors and virilization during puberty if chromosome Y-specific sequences are present. The role of the Y chromosome in human oncogenesis is still controversial. Even though gonadoblastoma is a benign tumor, it can undergo transformation into invasive dysgerminoma in 60% of the cases, and also into other, malignant forms of germ cell tumors. Although some authors have questioned the high incidence of gonadoblastoma (around 30%), the risk of developing any kind of gonadal lesion, whether tumoral or not, justifies investigation of Y-chromosome sequences by means of the polymerase chain reaction (PCR), a highly sensitive, low-cost and easy-to-perform technique. In conclusion, mosaicism of both the X and the Y chromosome is a common finding in TS, and detection of Y-chromosome-specific sequences in patients, regardless of their karyotype, is necessary in order to prevent the development of gonadal lesions.

Maternal endothelial progenitor colony-forming units with macrophage characteristics are reduced in preeclampsia

BACKGROUND

Endothelial progenitor cells (EPCs) provide paracrine support to the vascular endothelium and may also replace damaged or senescent endothelial cells. Low numbers of endothelial progenitor colony-forming units (CFU-ECs) in culture are a predictive biomarker of vascular disease. We hypothesized that the number of CFU-ECs derived from maternal blood are decreased in women with preeclampsia compared to normal pregnancy.

METHODS

Primigravid women with singleton normal (n = 12) or preeclamptic (n = 12) pregnancies were studied during the third trimester. The culture assay was performed using a pre-plating step to eliminate mature endothelial cells and nonprogenitor cells; colonies per well were counted and further characterized.

RESULTS

Colony numbers were fourfold lower on average in preeclampsia compared to control samples (P < 0.005). A majority of the cells comprising individual colonies were positive for both endothelial (Ulex europaeus lectin staining and acetylated low-density lipoprotein (LDL) uptake) and monocyte/macrophage (CD45, CD14, CD115) characteristics. The SRY gene was detected in CFU-ECs derived from umbilical cord blood samples from male fetuses but not in CFU-ECs from peripheral blood of mothers with male fetuses. Maternal plasma concentrations of the antiangiogenic factor, soluble fms-like tyrosine kinase-1 (sFlt-1) were elevated (P < 0.0001) whereas placental growth factor (PlGF) was reduced (P < 0.01) in women with preeclampsia, but these factors did not correlate with CFU-EC counts.

CONCLUSIONS

CFU-ECs derived from culture of peripheral blood mononuclear cells, a correlate of cardiovascular risk in nonpregnancy populations, are rarified in women with preeclampsia compared to normal pregnancy. PCR analysis is consistent with a maternal origin of these cells.

Molecular identification of chromosome Y sequences in Brazilian patients with Turner syndrome

The investigation of Y-specific sequences in patients with Turner Syndrome (TS) with karyotype 45,X or mosaic, has a fundamental role in the clinical management of these patients. The relationship between the presence of Y chromosome fragments and a higher risk of gonadoblastoma in TS has already been established. The aim of the study was to investigate the presence of Y-chromosome fragments in a population of 42 female Brazilian patients with TS from Mato Grosso state. Cytogenetic analysis has shown the karyotypes 45,X in 27 of them (64.3%) and mosaic in 15 (35.7%). The presence of the Y-primers SRY, DYZ3, ZFY, DYZ1, DYS1 and PABY was investigated in all patients. These markers were amplified by polymerase chain reaction (PCR) technique, using DNA genomic from peripheral blood lymphocytes. None of these patients had shown any Y-chromosome fragments when they were analysed only by the classic cytogenetic technique. The PCR analysis with the Y-specific sequences ZFY and DYZ3 were identified in two different patients (4.8%), both with karyotype 45,X. It was concluded that PCR is efficient in the investigation of hidden Y-fragments in TS patients. Therefore, this method should be included in the routine assistance of these patients.

Clinical implications of the detection of Y-chromosome mosaicism in Turner's syndrome: report of 3 cases

OBJECTIVE

To determine the clinical implications of the presence of a Y chromosome in Turner's syndrome patients with karyotype abnormalities.

DESIGN

To investigate the presence of Y-chromosome sequences in different tissue samples.

SETTING

Endocrinology outpatient clinic of a federal university in Brazil.

PATIENT(S)

Five Turner's syndrome patients with karyotype abnormalities such as marker chromosomes, additional material, or ring chromosomes.

INTERVENTION(S)

Peripheral blood, oral epithelial cells, and hair root samples were collected.

MAIN OUTCOME MEASURE(S)

The SRY gene and the DYZ3 repeat region were amplified by polymerase chain reaction followed by gel electrophoresis mobility of amplified genomic DNA, and ultraviolet visualization. Prophylactic gonadectomy was offered to the Y-positive patients.

RESULT(S)

The analysis of the different tissues revealed that three of the five patients studied presented Y-chromosome mosaicism. These three patients underwent prophylactic gonadectomy, and in one of them, the histopathologic study of the gonads disclosed hilus cell hyperplasia and stromal luteoma with contralateral nodular hyperthecosis.

CONCLUSION(S)

A systematic search for Y-chromosome mosaicism in Turner's syndrome patients is justified by the risk of developing gonadal tumors or androgen-producing lesions.

Detection of Y chromosomal material in patients with a 45,X karyotype by PCR method

A 45,X karyotype is one of the common chromosomal abnormalities characterized by short stature, lack of development of secondary sexual characteristics, webbed neck and cubitus valgus. This phenotype was described by Turner in 1938 and was called Turner syndrome (TS). About 40-60% of the patients with TS phenotype have a 45,X karyotype, the rest either have a structurally abnormal X or Y chromosome or mosaicism with a second cell line. Determination of Y chromosome derivatives in patients with a 45,X karyotype is important for the management of these patients due to increased risk of gonadoblastoma. Low level mosaicism of Y chromosome may be missed by cytogenetic methods. The aim of our study is to analyze cryptic Y chromosome derivatives using Y specific sequences in 40 Turkish patients with a pure 45,X karyotype. Fourteen different Y specific sequences along the Y chromosome were selected for the detection of cryptic Y chromosome material by PCR analysis. The present study demonstrated that 2 patients with a 45,X karyotype (5%) have Y specific sequences except sex related region Y (SRY). One of them had displayed enhanced virilisation whereas other showed no virilisation. In conclusion, it has been found by PCR analysis that 5% of patients with a 45,X karyotype have Y chromosome sequences in the absence of any marker chromosome by cytogenetic analysis. The data also suggest that the patients with a 45,X karyotype should be analyzed for the presence of Y chromosome derivatives by sensitive methods, such as PCR, in order to calculate the future risk of developing gonadoblastoma.

Neoplasms and pathology of sexual developmental disorders (intersex)

Continuing new insights into the biology of sexual development and advances in chromosome analysis have led to early identification and prompt treatment of the intersexual patient, the results of which facilitate a more normal life for affected individuals. Based on these advances, a classification of abnormal sexual development has been developed and refined that correlates the gonadal and genital anatomy with the chromosomal findings and specific genetic or metabolic defects. In a shift from a classification anchored on whether the intersex revolves about a specific gene or whole chromosomal abnormality, the current classification is organised by broader categories into which the intersexual disorders are divided into 'abnormalities of genital differentiation', due largely to the abnormal production or sensitivity of a single hormone, or 'abnormalities in sex determination', due to abnormal gonadal differentiation, usually testicular, with or without chromosomal aberration. The current classification is an integrated approach to this complex group of disorders and is organised according to the manner by which patients present as well as on the pathophysiological basis of the defect. The classification also groups patients who are at high risk for development of gonadal neoplasia.

Determination of the sexual phenotype in a child with 45,X/46,X,Idic(Yp) mosaicism: importance of the relative proportion of the 45,X line in gonadal tissue

We report on a girl who, despite her 45,X/46,X,der(Y) karyotype, showed no signs of virilization or physical signs of the Ullrich-Turner syndrome (UTS), except for a reduced growth rate. After prophylactic gonadectomy due to the risk of developing gonadoblastoma, the gonads and peripheral blood samples were analyzed by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) to detect Y-specific sequences. These analyses allowed us to characterize the Y-derived chromosome as being an isodicentric Yp chromosome (idic(Yp)) and showed a pronounced difference in the distribution of the 45,X/46,X,idic(Yp) mosaicism between the two analyzed tissues. It was shown that, although in peripheral blood almost all cells (97.5%) belonged to the idic(Yp) line with a duplicated SRY gene, this did not determine any degree of male sexual differentiation in the patient, as in the gonads the predominant cell line was 45,X (60%).

Detection of hidden Y mosaicism in Turner's syndrome: importance in the prevention of gonadoblastoma

The presence of Y chromosome fragments in patients with Turner's syndrome (TS) is known to increase the risk of gonadoblastoma. The investigation of Y sequences is usually performed only in the presence of marker chromosomes and therefore does not rule out the presence of hidden mosaicism in patients with 45,X TS without any marker.

AIMS

1. To investigate the presence of hidden Y mosaicism in non-mosaic 45,X patients with TS, using samples from different tissues, and its association with the development of gonadoblastoma.

STUDY DESIGN

Twenty patients with a 45,X karyotype were studied. The SRY and DYZ3 sequences were amplified by PCR, using genomic DNA from peripheral blood, oral epithelial cells and hair roots. Prophylactic gonadectomy was offered to the Y-positive patients.

RESULTS

The analysis of the different tissues revealed that seven (35%) out of the 20 patients studied presented hidden chromosome Y mosaicism. Four of these patients underwent prophylactic gonadectomy, and bilateral gonadoblastoma was found in one of them.

CONCLUSIONS

A systematic search for hidden Y chromosome mosaicism in patients with TS and 45,X karyotype is justified by the possibility of developing gonadoblastoma.

Germ cell tumors in the intersex gonad: old paths, new directions, moving frontiers

The risk for the development of germ cell tumors is an important factor to deal with in the management of patients with disorders of sex development (DSD). However, this risk is often hard to predict. Recently, major progress has been made in identifying gene-products related to germ cell tumor development (testis-specific protein-Y encoded and octamer binding transcription factor 3/4) and in recognizing early changes of germ cells (maturation delay, preneoplastic lesions, and in situ neoplasia). The newly recognized "undifferentiated gonadal tissue" has been identified as a gonadal differentiation pattern bearing a high risk for the development of gonadoblastoma. It is expected that the combination of these findings will allow for estimation of the risk for tumor development in the individual patient (high risk/intermediate risk/low risk). This article reviews the recent literature regarding the prevalence of germ cell tumors in patients with DSD. Some major limitations regarding this topic, including a confusing terminology referring to the different forms of intersex disorders and unclear criteria for the diagnosis of malignant germ cells at an early age (maturation delay vs. early steps in malignant transformation) are discussed. Thereafter, an overview of the recent advances that have been made in our knowledge of germ cell tumor development and the correct diagnosis of early neoplastic lesions in this patient population is provided. A new classification system for patients with DSD is proposed as a tool to refine our insight in the prevalence of germ cell tumors in specific diagnostic groups.

[Gonadal dysgenesis and tumors: genetic and clinical features]

Gonadal dysgenesis comprises a clinical spectrum of anomalies in patients with female, ambiguous or male phenotype, absent or impaired puberty and karyotype with or without Y chromosome and/or chromosome markers. Although Y-specific sequences are seldom cytogenetically evident, dysgenetic gonads are potentially prone to developing tumors. Gonadoblastoma, a mixed germ cell and sex-cord cells tumor with variable degree of focal calcification, is the most harmful due to its frequency. Other gonadal tumor, malign or not, also occur in gonadal dysgenesis. As they are not metastatic tumors and may be eradicated by selective excisions, the importance of detecting Y-sequences by molecular sensitized techniques is stressed in order to indicate prophylactic gonadectomy.

Gonadoblastoma in Turner syndrome and Y-chromosome-derived material

The identification of Y-chromosome material is important in females with Ullrich-Turner syndrome (UTS) due to the risk of developing gonadoblastoma or other gonadal tumors. There is controversy regarding the frequency of the Y-chromosome-derived material and the occurrence of gonadoblastoma in these patients. The aim of our study was to evaluate a large number of patients with UTS, followed before and during the pubertal age for the prevalence of Y-chromosome derived material, the occurrence of gonadoblastoma, and the incidence of possible neoplastic degeneration. An unselected series of 171 patients with UTS (1-34 years old), diagnosed cytogenetically, was studied for Y-chromosome markers (SRY and Y-centromeric DYZ3 repeats). The follow-up was of 2-22 years; 101 of these patients were followed during pubertal age. Y-chromosome material was found in 14 patients (8%): 12 of these were gonadectomized (2.8-25.9 years). A gonadoblastoma was detected in four patients under 16 years of age: in two, Y-material was detected only at molecular analysis (at conventional cytogenetic analysis, one was included in the 45,X group and one in the X + mar group) and one had also an immature teratoma and an endodermal sinus carcinoma. The prevalence of gonadoblastoma in our series of gonadectomized UTS patients with Y-positive material was of 33.3% (4/12). Our data suggest that the age of appearance and the possibility of malignant degeneration of gonadoblastoma can occur early in life. These patients, in particular those with 45,X or a marker chromosome may benefit from molecular screening to detect the presence of Y-chromosome material; PCR is a rapid and inexpensive technique. At the moment, laparoscopy and preventive gonadectomy performed as soon as possible remain the procedures of choice for patients with UTS, when Y-chromosome has been identified, as we are still unable to predict a future malignant evolution of gonadoblastoma.

Histologic analysis of gonadal tissue in patients with Ullrich-Turner syndrome and derivative Y chromosomes

To identify patients who had Ullrich-Turner syndrome (UTS) and were at risk for gonadoblastoma or associated germ cell tumors, molecular genetic analysis was carried out to detect Y chromosomal sequences. From peripheral blood samples of 5 patients who had cytogenetically confirmed UTS, genomic DNA was extracted and screened for Y chromosomal sequences by polymerase chain reaction. The morphology of the gonadal tissues was compared with results from polymerase chain reaction. Three phenotypic females showed UTS mosaicism with normal X chromosome accompanied by Y chromosomal material, and 2 patients showed marker chromosomes. Molecular analysis represented loci PABY, SRY, ZFY, TSPY, DYZ3, DYZ1 DXYS, 19Y, DYS-273, DYS-148, DYS218, DYS224, and DYZ1. Three patients showed gonadal tumors (1 with unilateral gonadoblastoma, 1 with unilateral dysgerminoma, and 1 patient had both tumors in 1 gonad). Molecular genetic screening for Y chromosomal sequences may be useful as an additional tool for the identification of patients at risk for a gonadal tumor. Careful, complete processing, including step sectioning, of the gonadectomy specimens to detect small lesions is recommended.

Refined quantitative fluorescent PCR of Y-chromosome DNA sequences mosaics in Turner's syndrome patients—alternative to real-time PCR

BACKGROUND

Real-time polymerase chain reactions (PCRs) are the most frequently used techniques for gonosomal mosaics quantification. The primary aim of this work is to assess and optimize the refined technique of quantitative fluorescent polymerase chain reaction (RQF PCR) in the quantification of Y-chromosome sequences in gonosomal mosaics. The method was applied to the analysis of Y-chromosome sequences (amelogenin gene, AMELX/Y-loci) in peripheral lymphocytes and gonadal tissues in Y-positive Turner's syndrome (TS) patients.

METHODS

RQF PCR was used for molecular quantification, and fluorescent in situ hybridization (FISH) technique was used for comparison.

RESULTS

Based on a formulated calibration curve, DNA mosaics from six Y-positive patients and gonads from one patient were deducted. For calculation of rare mosaics, it is possible to take advantage of a new empirical formula. FISH results were comparable to RQF PCR.

CONCLUSION

The sensitivity of RQF PCR brings significant progress in the analysis of gonosomal aberrations. RQF PCR also finds applications in prenatal diagnostics of maternal contaminations of amniotic fluid and foetal DNA in maternal blood and analysis of chimerism in patients after bone marrow transplantation. The method is very convenient for determining the number of testis-specific protein, Y-linked (TSPY) gene repetitions.

Gonadoblastoma in Turner syndrome patients with nonmosaic 45,X karyotype and Y chromosome sequences

Turner syndrome (TS) is a disorder caused by partial or complete X-chromosome monosomy. Studies in TS patients with different karyotypes have demonstrated the presence of Y-chromosome-derived sequences (4-61%). Early detection of Y-chromosome sequences in TS is of great importance because of the high risk of gonadal tumor development. We investigated the presence of Y-chromosome sequences in TS patients with a 45,X karyotype. One hundred seven unrelated 45,X Mexican TS patients recruited between 1992 and 2003 were included. Y-chromosome-derived sequences were found by polymerase chain reaction in 10 (9.3%) patients. Six subjects underwent gonadectomy and in one of them a gonadoblastoma was found; another developed a gonadoblastoma with dysgerminoma. Because of the high proportion (33%) of gonadal tumors in patients with Y-chromosome sequences found among our patients of mestizo origin, adequate counseling regarding a gonadectomy should be given.

Molecular and cytogenetic characterization of extra-structurally abnormal chromosomes (ESACs) found prenatally: outcome and follow-up

A 40-year-old woman underwent amniocentesis at 15.3 weeks of gestation. Chromosome analysis performed using QFQ, DA-DAPI and CBG banding revealed two de novo extra-chromosomal markers (ESACs) in 11 of the 16 colonies analysed. Fluorescence in situ hybridization (FISH) showed that both chromosomes came from the Yq11.22.1 region of the Y chromosome. PCR analysis of genes and STS localized on the Y chromosome excluded the Yp presence specifically of the SRY gene, and most of the euchromatic region of Yq. After extensive genetic counselling and considering both laboratory and second-level ultrasound data, the couple decided to continue the pregnancy. At 37.4 weeks of gestational age, a girl weighing 2750 g was born with an Apgar score of 9/10. A blood sample taken from the umbilical cord showed three cellular lines: mos47,XX, +mar1 ish.der (Y)(wcpY+) [21%]/48,XX, +mar1 ish.der (Y)(wcpY+), +mar2 ish.der (Y)(wcpY+) [41%]/46,XX [38%]. One year after birth, the baby was developing normally and had normal psychomotorial activity.

Complex chromosome re-arrangement 45,X,t(Y;9) in a girl with sex reversal and mental retardation

A girl with mental retardation and multiple minor anomalies was found to have a complex chromosome 9p re-arrangement comprising a deleted, translocated Y chromosome, a deletion of the sex reversal gene region (DMRT1) at 9p, together with an inverted duplication of the more proximal part of 9p. The karyotype was 45,X,der(Y;9)(Ypter-->Yq12::9p21.1-->9p22.2::9p22.2-->9qter) de novo. The karyotypic male, phenotypic female had a dysgerminoma of the left dysplastic ovary. The patient had typical 'trisomy 9p' syndrome, and we propose that the critical region for this phenotype is located between 9p22.1 and 9p22.2.

Ultrasound of a Patient With Gonadal Dysgenesis and Mixed Malignant Germ Cell Tumor

Both ovarian malignancy and gonadal dysgenesis in the adolescent period are rare. Ovarian tumors represent approximately 1% of childhood malignancies. Gonadal dysgenesis is also unusual and results when the germ cells are lacking and the ovary is replaced by a fibrous streak. An 18-year-old with primary amenorrhea,acute pelvic pain,and a 16-cm pelvic mass was found to have both a malignant mixed germ cell tumor and a contralateral streak ovary.

Detection of Y-specific sequences in 122 patients with Turner syndrome: nested PCR is not a reliable method

The incidence of Y chromosome sequences in patients with Turner syndrome has been evaluated in several studies, and its frequency varied from 0% to 61%, depending on the molecular methodology used. The aim of our study was to screen for Y chromosome sequences in 122 patients with Turner syndrome without cytogenetic evidence of this chromosome. DNA of 100 normal women was also screened and it was used as a negative control. To identify cryptic Y mosaicism, eight regions of Y chromosome were amplified by PCR. In order to increase the sensitivity of Y sequence detection, a nested PCR of the SRY and TSPY genes was also performed. All patients had several stigmata of Turner syndrome and none of them presented with signs of virilization. The most frequent karyotype was 45,X (54.1%), followed by mosaicism involving structural aberration of the X chromosome. There were 12 patients who carried a marker or ring chromosome. First-round PCR identified Y chromosome sequences in only four patients (3%), and all of them had a chromosome mosaicism with at least one cell lineage with a marker chromosome. After nested PCR, 25% of the patients and 14% of the normal women were positive for the presence of Y sequences. Contamination with extraneous genomic DNA was ruled out by microsatellite studies, but we cannot eliminate the possibility of contamination with PCR products, despite careful handling. We conclude that nested PCR overestimated the frequency of Y sequences in patients with Turner syndrome and should be avoided to prevent false positive results, which lead to unnecessary surgical treatment of these patients.

Turner's syndrome in adulthood

Turner's syndrome is the most common chromosomal abnormality in females, affecting 1:2,500 live female births. It is a result of absence of an X chromosome or the presence of a structurally abnormal X chromosome. Its most consistent clinical features are short stature and ovarian failure. However, it is becoming increasingly evident that adults with Turner's syndrome are also susceptible to a range of disorders, including osteoporosis, hypothyroidism, and renal and gastrointestinal disease. Women with Turner's syndrome have a reduced life expectancy, and recent evidence suggests that this is due to an increased risk of aortic dissection and ischemic heart disease. Up until recently, women with Turner's syndrome did not have access to focused health care, and thus quality of life was reduced in a significant number of women. All adults with Turner's syndrome should therefore be followed up by a multidisciplinary team to improve life expectancy and reduce morbidity.

Tumors of the testis in intersex syndromes

Patients with intersex syndrome are rare in the general population. In these patients, cryptorchid gonads that have an Y chromosome or Y chromosomal material are at risk for development of germinal and non-germinal neoplasm and non-neoplastic masses. Diagnosis of individual patients should be accurate for optimal care and risk assessment.

Insights into causes of sexual ambiguity

Our understanding of the causes of sexual ambiguity has progressed from the determination of the hormonal etiologies to defining the genetic basis of intersex disorders. The localization of specific genes involved in the process of sexual differentiation has made it possible to determine the mutations and other molecular events that result in sexual ambiguity. With this information, some disorders can now be diagnosed before birth and possibly even treated in utero.