Y chromosome sequences in Turner's syndrome: association with virilization and gonadoblastoma

Prevalence and characteristics of gonadoblastoma in a retrospective multi-center study with follow-up investigations of 70 patients with Turner syndrome and a 45,X/46,XY karyotype

INTRODUCTION

A gonadectomy is currently recommended in patients with Turner syndrome (TS) and a 45,X/46,XY karyotype, due to a potential risk of gonadoblastoma (GB). However, the quality of evidence behind this recommendation is low.

OBJECTIVE

This study aimed to evaluate the prevalence of GB, its characteristics, as well as its risk factors, according to the type of Y chromosomal material in the karyotype.

METHODS

Our study within French rare disease centers included patients with TS and a 45,X/46,XY karyotype, without ambiguity of external genitalia. Clinical characteristics of the patients, their age at gonadectomy, and gonadal histology were recorded. The regions of the Y chromosome, the presence of TSPY regions, and the percentage of 45,X/46,XY mosaicism were evaluated.

RESULTS

A total of 70 patients were recruited, with a median age of 29.5 years (21.0-36.0) at the end of follow-up. Fifty-eight patients had a gonadectomy, at a mean age of 15 ± 8 years. GB was present in nine cases. Two were malignant, which were discovered at the age of 14 and 32 years, without metastases. Neither the percentage of XY cells within the 45,X/46,XY mosaicism nor the number of TSPY copies was statistically different in patients with or without GB (P = 0.37). However, the entire Y chromosome was frequent in patients with GB (6/9).

CONCLUSIONS

In our study, including a large number of patients with 45,X/46,XY TS, the prevalence of gonadoblastoma is 12.8%. An entire Y chromosome appears as the main risk factor of GB and should favor early gonadectomy.

SIGNIFICANT STATEMENT

About 10% of patients with TS have a karyotype containing Y chromosomal material: 45,X/46,XY. Its presence is related to the risk of GB. Therefore, a prophylactic gonadectomy is currently recommended in such patients. However, the quality of evidence is low. Our objective was to evaluate the prevalence of GB according to the type of Y-chromosomal material. We found a prevalence of GB of 12.8% in a cohort of 70 TS patients. No sign of hyperandrogenism was observed. The entire Y chromosome was the most frequent type of Y-material in patients with GB. As the prognosis of these tumors was good, a delay of surgery might be discussed.

Neoplasia in Turner syndrome: a retrospective cohort study in a tertiary referral centre in Belgium

OBJECTIVES

Patients with Turner syndrome (TS), the most common sex chromosome abnormality in women, can suffer from a variety of well-researched reproductive, cardiovascular, metabolic, and autoimmune comorbidities. Few studies investigate the neoplasia risk. We assessed the general neoplasia risk in TS women, and more specifically, the gonadoblastoma/dysgerminoma risk in the subgroup with Y chromosome mosaicism, and evaluated potential risk factors for neoplasia development, such as karyotype, metabolic and autoimmune comorbidity, and treatment with growth hormone and/or estrogen replacement.

DESIGN

10-year retrospective cohort study in a tertiary referral centre in Belgium.

RESULTS

105 TS women were included (median age 29; range 2-69). Six malignant tumours were detected in 5 (4.8%) patients (SIR = 0.6, 95% CI 0.2-1.0). In addition, 2 benign meningiomas were observed, resulting in 3 (2.9%) tumours of the central nervous system (CNS; SIR = 19.9, 95% CI 4.0-35.8). No breast cancer was noted. Benign neoplasms occurred in 22 women (21.0%), with skin lesions being the most frequent. All patients with Y chromosome mosaicism (n = 9; 8.6%) underwent prophylactic gonadectomy, but gonadoblastoma/dysgerminoma was not detected. A weak association was found between any tumour type and autoimmune comorbidity (r = 0.24; p = 0.02).

CONCLUSION

The overall malignancy risk was not increased, but a different pattern of occurrence is apparent, with an increased risk of CNS and skin tumours and a decreased breast cancer risk. Gonadoblastoma/dysgerminoma was not reported. There is a need for centralised multidisciplinary care and prospective research to unravel and predict the neoplasia risk.

Recognition and management of adults with Turner syndrome: From the transition of adolescence through the senior years

Turner syndrome is recognized now as a syndrome familiar not only to pediatricians and pediatric specialists, medical geneticists, adult endocrinologists, and cardiologists, but also increasingly to primary care providers, internal medicine specialists, obstetricians, and reproductive medicine specialists. In addition, the care of women with Turner syndrome may involve social services, and various educational and neuropsychologic therapies. This article focuses on the recognition and management of Turner syndrome from adolescents in transition, through adulthood, and into another transition as older women. It can be viewed as an interpretation of recent international guidelines, complementary to those recommendations, and in some instances, an update. An attempt was made to provide an international perspective. Finally, the women and families who live with Turner syndrome and who inspired several sections, are themselves part of the broad readership that may benefit from this review.

Hepatocellular Carcinoma, Virilization, and Hilus Cell Hyperplasia in a Girl With Turner Syndrome

Patients with Turner syndrome (TS) are known to be at risk for excess androgen production and virilization associated with gonadoblastoma and Y chromosome mosaicism, and excess androgens are a risk factor for the development of hepatocellular carcinoma. However, virilization and hepatocellular carcinoma have not been described in a patient with TS. A 10-year-old with nonmosaic 45,X TS presented with clitoromegaly, accelerated linear growth velocity, advanced bone age, and elevated testosterone levels as well as a second occurrence of hepatocellular carcinoma. Gonadectomy was performed, and pathology revealed hilus cell hyperplasia. Immunohistochemical staining of both the original and recurrent hepatocellular carcinoma tissues was diffusely positive for androgen receptors. After gonadectomy, testosterone levels were measurable but normal, with no further virilization; however, the liver mass continued to grow. Ovarian hilus cell hyperplasia should be considered a potential etiology for virilization in the TS population. Excess endogenous testosterone exposure in girls and women with TS may be associated with hepatocellular carcinoma expressing the androgen receptor, though normalizing testosterone levels may not lead to tumor regression in these cases.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Gonadoblastoma in patients with 45,X/46,XY mosaicism: A 16-year experience

BACKGROUND

It is recognised that individuals with a 45,X/46,XY karyotype, known as Turner mosaic syndrome with Y chromosome material (TMSY), have an increased risk of developing gonadoblastoma (GB), which may then devolve into one of a number of germ cell malignancies. Hence, children with TMSY are usually recommended to undergo prophylactic gonadectomy.

OBJECTIVE

We designed this study to describe the phenotypic features of our series of children with TMSY who underwent prophylactic gonadectomy in order to evaluate the prevalence of GB and germ cell malignancies in their resected specimens.

STUDY DESIGN

This is a retrospective case series wherein we comprehensively reviewed the clinical, histological, and cytogenetic features of all patients who underwent prophylactic gonadectomy at three tertiary paediatric referral centres over 16 years. Cases were identified from surgical logbooks and through the institutional histopathology database. Data were collected with particular reference to clinical phenotype, predominant karyotype cell line, operative management, anatomical findings and the presence of neoplastic changes.

RESULTS

Fourteen children ranging in age at the time of surgery from 2 weeks to 17 years were included in the series. Eleven children were reared as females. The three children who were reared as males had severe penoscrotal hypospadias. The 46,XY cell line was the predominant cell line in seven (50%) cases in blood lymphocytes. The resected specimens from four patients (28.6%) contained GB, with three patients having bilateral GB. This sub-group of patients with GB were aged 5 months, 48 months, 71 months, and 13 years. GB arose in one patient with and three patients without genital virilisation. There was no focus of invasive germ cell tumour in any specimen.

DISCUSSION

GB may be present in infants with TMSY as young as 5 months, even with low levels of Y chromosome material. The prevalence of GB in prophylactic gonadectomy specimens is similar to many previously reported series, although the absence of dysgerminoma in our series is reassuring. The exclusive presence of GB in intra-abdominal gonads is in keeping with the findings of several other series.

CONCLUSION

Owing to the presence of gonadoblastoma in the gonads of children with TMSY as young as 5 months, we recommend that all patients with intra-abdominal gonads in the context of TMSY should duly undergo prophylactic gonadectomy, although the timing of such surgery can be discussed with parents during counselling regarding the risk of malignancy.

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.

Transitions in endocrinology: treatment of Turner's syndrome during transition

Transition in health care for young patients with Turner's syndrome (TS) should be perceived as a staged but uninterrupted process starting in adolescence and moving into adulthood. As a condition associated with high risk of short stature, cardiovascular diseases, ovarian failure, hearing loss and hypothyroidism, TS requires the attention of a multidisciplinary team. In this review paper, we systematically searched the relevant literature from the last decade to discuss the array of problems faced by TS patients and to outline their optimal management during the time of transfer to adult service. The literature search identified 233 potentially relevant articles of which 114 were analysed. The analysis confirmed that all medical problems present during childhood should also be followed in adult life. Additionally, screening for hypertension, diabetes mellitus, dyslipidaemia, and osteoporosis is needed. After discharge from the paediatric clinic, there is still a long way to go.

t(6;9)(p23;q34) presenting acute myeloid leukemia in a child with an unsuspected 45,X/46,X,derY [?t(Yp;Yq)] chromosomal constitution: yet another Y chromosome overdosage and malignancy association

Development of leukemia in patients with sexual chromosome abnormalities is relatively rare and mostly involves cases of monosomy X, Turner syndrome. Here, we report on a child having a 45,X/46,X,derY [?t(Yp;Yq)] chromosomal constitution (variant Turner syndrome) presenting with concordant acute myeloid leukemia and a rarely seen clonal neoplasic cell lineage-related karyotype, t(6;9)(p23;q34).

Dysgerminoma in a female with turner syndrome and Y chromosome material: A case-based review of literature

We report a 17-year-old girl evaluated for primary amenorrhea. Cytogenetic analysis of the peripheral blood lymphocytes revealed normal autosomes with 46X inv (Y) confirming the diagnosis of Turner's syndrome with Y cell line. Treatment was initiated with conjugated estrogen while recommending bilateral prophylactic oophorectomy to the patient. One year later the patient presented with abdominal mass, biopsy of the specimen following resection confirmed dysgerminoma originating from right ovary with no invasion or metastasis. The literature is reviewed with regard to the various pathogenetic mechanisms proposed for the development of germ cell tumors in ovary, the cytogenetic findings and recommendations to handle such scenario.

OCT4 immunohistochemistry may be necessary to identify the real risk of gonadal tumors in patients with Turner syndrome and Y chromosome sequences

BACKGROUND

The aim of this study was to investigate the frequency of gonadal tumors among patients with Turner syndrome (TS) carrying Y-derivative sequences in their chromosomal constitution.

METHODS

Six out of 260 patients with TS were selected based on mosaicism of the entire Y chromosome; 10 were included because Y-derivative sequences have been detected by PCR with specific oligonucleotides (sex-determining region on the Y, testis specific-protein, Y and DYZ3) and further confirmed by FISH. The 16 patients were subjected to bilateral gonadectomy at ages varying from 8.7 to 18.2 years. Both histopathological investigation with hematoxylin and eosin (H&E) and immunohistochemical analysis with anti-octamer-binding transcription factor 4 (OCT4) antibody were performed.

RESULTS

Gonadal neoplasia was not detected in any of the 32 gonads evaluated by H&E; however, four gonads (12%) from three patients (19%) had positive OCT4 staining in 50-80% of nuclei, suggesting the existence of germ cell tumors (gonadoblastoma or in situ carcinoma).

CONCLUSIONS

Evaluation of the real risk of development of gonadal tumors in TS patients with Y-derivative sequences in their chromosomal constitution may require a specific histopathological study, such as immunohistochemistry with OCT4.

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.

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.

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.

The Y-encoded TSPY protein: a significant marker potentially plays a role in the pathogenesis of testicular germ cell tumors

The testis-specific protein Y-encoded (TSPY) gene is the putative gene for the gonadoblastoma locus on the Y chromosome (GBY) that predisposes dysgenetic gonads of intersex patients to gonadoblastoma development. TSPY is expressed at high levels in gonadoblastoma tissues, supporting its possible oncogenic function in this type of germ cell tumors. To explore the possibility that this Y chromosome gene is also involved in pathogenesis of the more common testicular germ cell tumors (TGCTs), we have conducted various expression studies using immunohistochemistry, Western blotting, and reverse transcription-polymerase chain reaction analysis on 171 cases of TGCTs and selected normal testis controls. Our results demonstrated that TSPY protein is abundantly expressed in the precursor, carcinoma in situ or intratubular germ cell neoplasia unclassified, and seminoma, but only minimally or not expressed in various types of nonseminomas. TSPY coexpresses with established germ cell tumor markers (such as placental-like alkaline phosphatase, c-KIT, OCT4) and proliferative markers (such as Ki-67 and cyclin B1) in the same tumor cells at both RNA and protein levels. Ectopic TSPY expression in cultured cells up-regulates progrowth genes, including those at chromosome 12p13, frequently gained/amplified in TGCTs. Our results suggest that TSPY, in combination with other markers, could be an important marker for diagnosis and subclassification of TGCTs and support its role in the pathogenesis of both gonadoblastoma and TGCTs.

Testis-specific protein Y-encoded gene is expressed in early and late stages of gonadoblastoma and testicular carcinoma in situ

The testis-specific protein Y-encoded gene (TSPY) is a tandem repeat gene located at the critical region for the gonadoblastoma locus on Y chromosome that predisposes the dysgenetic gonads of intersex individuals to oncogenesis. The expression and molecular properties of TSPY suggest that it is the putative gene for the gonadoblastoma locus on Y chromosome. In this study, we examined the expression of TSPY and other germ cell tumor markers in 4 cases of gonadoblastoma using immunostaining techniques. Our results showed that TSPY expression was closely associated with initiation and various stages of gonadoblastoma development. TSPY protein localized with established germ cell tumor markers, such as the placental alkaline phosphatase, c-KIT, and OCT3/4, in the same tumor cells of both gonadoblastoma and adjacent carcinoma in situ, the precursor for germ cell tumors. These findings support the candidacy of TSPY as the gene for the gonadoblastoma locus on Y chromosome and suggest that TSPY could be a significant marker for these types of germ cell tumors.

Germ cell tumor showing partial trisomy 1 in a gonadectomized intersex child with monosomy X and double Y mosaicism

High incidence of germ cell tumors arising from dysgenetic gonads in patients with sexual chromosome abnormalities has been described, especially in patients with a Y chromosome bearing cell line. Here we report a 14-year-old patient with ambiguous genitalia. Constitutional karyotype showed 45,X/46,X,derY [?t(Yp;Yq)] mosaicism. The patient developed an abdominally located mixed malignant germ cell tumor 5 years after the removal of the dysgenetic gonads. Tumor karyotype showed partial trisomy 1q, a derivative 8q, and a hyperdiploidy with +X, +7, +12, +15, +19, +21, and an unidentified marker.

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.

Human Y-chromosome variation and male dysfunction

The Y-chromosome is responsible for sex determination in mammals, which is triggered by the expression of the SRY gene, a testis-determining factor. This particular gene, as well as other genes related to male fertility, are located in the non-recombining portion of the Y (NRY), a specific region that encompasses 95% of the human Y-chromosome. The other 5% is composed of the pseudo-autosomal regions (PARs) at the tips of Yp and Yq, a X-chromosome homologous region used during male meiosis for the correct pairing of sexual chromosomes. Despite of the large size of the human NRY (about 60 Mb), only a few active genes are found in this region, most of which are related to fertility. Recently, several male fertility dysfunctions were associated to microdeletions by STS mapping. Now that the complete genetic map of the human Y-chromosome is available, the role of particular NRY genes in fertility dysfunctions is being investigated. Besides, along with the description of several nucleotide and structural variations in the Y-chromosome, the association between phenotype and genotype is being addressed more precisely. Particularly, several research groups are investigating the association between Y-chromosome types and susceptibility to certain male dysfunctions in different population backgrounds. New insights on the role of the Y-chromosome and maleness are being envisaged by this approach.