Y chromosome sequences in Turner's syndrome and risk of gonadoblastoma or virilisation

Deficient knowledge in adult Turner syndrome care as an incentive to found Turner centers in Germany

OBJECTIVE

Turner syndrome (TS) is characterized by the complete or partial loss of the second sex chromosome and associated with a wide range of clinical manifestations. We aimed to assess the medical care of adult patients with TS in Germany.

DESIGN

Retrospective multicenter observational study.

METHODS

Data were collected from medical records of 258 women with TS treated between 2001 and 2017 in five non-university endocrinologic centers in Germany.

RESULTS

Mean age was 29.8 ± 11.6 years, mean height 152 ± 7.7 cm, and mean BMI 26.6 ± 6.3 kg/m2. The karyotype was known in 50% of patients. Information on cholesterol state, liver enzymes, and thyroid status was available in 81-98% of women with TS; autoimmune thyroiditis was diagnosed in 37%. Echocardiography was performed in 42% and cardiac MRI in 8.5%, resulting in a diagnosis of cardiovascular disorder in 28%. Data on growth hormone therapy were available for 40 patients (15%) and data concerning menarche in 157 patients (61%).

CONCLUSION

In 258 women with TS, retrospective analysis of healthcare data indicated that medical management was focused on endocrine manifestations. Further significant clinical features including cardiovascular disease, renal malformation, liver involvement, autoimmune diseases, hearing loss, and osteoporosis were only marginally if at all considered. Based on this evaluation and in accordance with recent guidelines, we compiled a documentation form facilitating the transition from pediatric to adult care and further medical management of TS patients. The foundation of Turner Centers in March 2019 will improve the treatment of TS women in Germany.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Malignancy in disorders of sex development

Disorders of sex development (DSD) represent a spectrum of conditions in which chromosomal, gonadal, or anatomic sex are atypical and affect 1 in 4,500-5,000 live births. The diagnosis of DSD raises concerns of tumor risk and treatment as well as future fertility preservation. We review the current understanding of the types of gonadal tumors that arise in DSD patients as well as possible markers and treatment. The goal is to inform the members of the DSD team (urologist, endocrinologist, geneticist, psychologist) of the latest findings regarding malignancy in DSD. PubMed^® and Google Scholar^TM literature searches were performed of current and past peer-reviewed literature on DSD (intersex) regarding gonadal development and tumor formation/treatment. Relevant reviews and original research articles were examined, including cited references, and a synopsis of the data was generated. DSD patients are at increased risk for the development of testicular carcinoma in-situ (CIS) and germ cell tumors (GCT), including seminoma, non-seminoma, juvenile granulosa cell, gonadoblastoma, and dysgerminoma. Cancer risk factors include Y-chromosomal material and gonadal position, especially for streak gonads. The 46 XX DSD patients [congenital adrenal hyperplasia (CAH)] with no genetic Y-chromosomal material are not at higher risk of cancer. Post-pubertal complete androgen insensitivity syndrome (AIS) patients remain prone to tumor development if the testes remain in the abdomen. Estimates of the risk of GCT in partial AIS for untreated undescended testes may be as high as 50%. The cancer risk of scrotal testes in partial AIS is unknown. CIS occurs almost exclusively in patients with hypovirilization, most notably in AIS. Persistent Mullerian Duct Syndrome (PMDS) confers the usual cancer risk associated with cryptorchidism, but also a possible tumor risk of the Mullerian remnant. Several markers are under investigation for tumor evaluation in the DSD population beyond hCG and AFP (Oct3/4, TSPY, WT-1). The management of patients with DSD is complex and evaluation of tumor risk is aided by advances in genotyping for Y-chromosomal material not evident in traditional karyotyping. More complete genetic screening for DSD patients should increasingly become the standard of care. Developments in pathologic diagnosis will further challenge our traditional understanding of the oncologic management and surveillance of these patients. Future studies utilizing more advanced histologic examination of gonads will improve our understanding of the true incidences of malignancy in this diverse population.

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.

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.

Cytogenetic findings in Serbian patients with Turner's syndrome stigmata

Cytogenetic findings are reported for 31 female patients with Turner's syndrome. Chromosome studies were made from lymphocyte cultures. Non-mosaicism 45,X was demonstrated in 15 of these patients, whereas only three were apparently mosaic. Eight patients showed non-mosaic and four patients showed mosaic structural aberrations of the X-chromosome. One non-mosaic case displayed a karyotype containing a small marker chromosome. Conventional cytogenetics was supplemented by fluorescence in situ hybridization (FISH) with an X-specific probe to identify the chromosomal origin of the ring and a 1q12-specific DNA probe to identify de novo balanced translocation (1;9) in one patient. To our knowledge, this is the first finding of karyotype 45,X,t(1;9)(cen;cen)/46,X,r(X),t(1;9)(cen;cen) in Turner's syndrome. The same X-specific probe was also used to identify a derivative chromosome in one patient.

Y-chromosome markers in Turner syndrome: Screening of 130 patients

BACKGROUND

The presence of Y-chromosome material in patients with Turner syndrome (TS) is a risk factor for the development of gonadoblastoma. Cytogenetic analysis detects Y-chromosome mosaicism in about 5% of Turner patients. However, if Y-chromosome sequences are present in only a few cells, they may be missed by routine analysis. The use of molecular techniques to detect the presence of Y-chromosome fragments in such patients is becoming increasingly important.

AIM

The objective of our study was to analyze cryptic Y-chromosome derivatives in Hungarian TS patient population by real-time PCR (RT-PCR).

SUBJECTS AND METHODS

Cytogenetic and RT-PCR methods were used to examine peripheral blood DNA of 130 Hungarian patients with TS for the presence of Y-chromosome. With RT-PCR, 4 regions throughout the Y-chromosome were analyzed.

RESULTS

Initial cytogenetic karyotyping assessing 10-50 metaphases revealed 3 patients with Y-chromosome positivity. RT-PCR revealed further 6 patients with Y-chromosome, who were initially considered as Y-negatives by standard kayotyping. The consecutive cytogenetic analysis of a large number (about 100) of metaphases (in 5 patients) and/or FISH (in 6 patients) however, also confirmed the presence of the Y-chromosome in these patients. Prophylactic gonadectomy was carried out in all 9 patients and 1 of them was diagnosed as having bilateral gonadoblastoma without clinical symptoms.

CONCLUSIONS

We recommend a routine molecular screening for hidden Y-chromosome sequences in Turner patients, who are negative for Y-chromosome by conventional cytogenetic analysis, in order to calculate the future risk of developing gonadoblastoma.

Gonadoblastoma and Turner syndrome

PURPOSE

The presence of a Y chromosome in the extrascrotal gonad of patients with intersex disorders has been associated with a high risk of GB and, potentially, GCT. Recently, modern sophisticated genotyping has revealed a subgroup of TS cases with a mosaic karyotype expressing a Y chromosome. We sought to evaluate this group of patients and address their risk of gonadoblastoma.

MATERIALS AND METHODS

We reviewed the records and genotyping of all females newly diagnosed with TS between 1990 and 2002 at Children's Hospital in Denver. All patients with TS and Y chromosome mosaicism underwent gonadectomy, and the specimens were evaluated for the presence of gonadoblastoma on histological analysis and to identify Y chromosome on genotyping.

RESULTS

A total of 192 girls with a clinical diagnosis of TS were identified between January 1990 and December 2002. Seven records were unavailable and 19 patients did not have karyotypic analyses available in the hospital charts. Of the remaining 166 patients 67 exhibited mosaic cell lines, of whom 8 had 45,X0/46,XY mosaic pattern and 59 had mosaic patterns without Y chromosomal elements. All 8 patients with Y mosaicism underwent uneventful laparoscopic gonadectomy on an outpatient basis. One patient observed to have bilateral dysgenetic gonads after gonadectomy was excluded from the study. Gonadoblastoma (bilateral 2 patients, unilateral 1) was detected in 3 of 7 patients (43%) with Y mosaicism.

CONCLUSIONS

In our series 4.8% of evaluable patients with TS carried a 45,X0/46,XY karyotype. Gonadoblastoma can be evident even at an early age in streak gonads with Y mosaicism and may be bilateral. We recommend prophylactic laparoscopic gonadectomy of streak gonads in patients with TS who carry a Y mosaic genotype, because fertility is not an issue, surgical morbidity is minor and there may be a high potential for malignant transformation of gonadoblastomas in this population.

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.

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 analysis in Turner syndrome

OBJECTIVE

The frequency of Y-chromosome material is high in Turner syndrome (TS), but the ocurrence of gonadoblastoma seems to be low. We performed a study to evaluate whether DNA analysis might be a useful tool in the evaluation of patients with TS.

SUBJECTS

Unrelated patients with TS (n = 52) of Venezuelan mestizo ethnic origin were diagnosed by cytogenetic analysis as having TS.

METHODS

Clinical assessment, karyotyping, endocrine evaluation, fluorescence in situ hybridization, and polymerase reaction chain analysis of the Y-chromosome loci.

RESULTS

We found that 7.69% (4 of 52) patients with TS had Y-chromosome material. A low occurrence of gonadoblastoma was also found (2 of 52 [3.85%]). Two patients showed a 45,X/46,XY karyotype, and gonadoblastoma in the gonadal biopsy specimen was not found. Two patients had no Y chromosome on initial karyotype; they were positive on lymphocyte DNA to Y-sequences specific. Both patients (45,X) had bilateral gonadoblastoma. The four patients with Y-chromosome material in peripheral blood lymphocytes had Y-chromosome sequences on gonadal DNA. Fluorescence in situ hybridization confirmed their Y-chromosome origin.

CONCLUSIONS

Our results suggest that the detection of Y-chromosome material should be carried out in all patients with TS and not be limited to patients with TS with cytogenetically identifiable Y chromosome and/or virilization.

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.

PCR-PRINS-FISH analysis of structurally abnormal sex chromosomes in eight patients with Turner phenotype

According to cytogenetic analysis, about 50% of Turner individuals are 45,X. The remaining cases have a structurally abnormal X chromosome or are mosaics with a second cell line containing a normal or abnormal sex chromosome. In these mosaics, approximately 20% have a sex marker chromosome whose identity cannot usually be determined by classical cytogenetic methods, requiring the use of molecular techniques. Polymerase chain reaction (PCR), primed in situ labeling (PRINS), and fluorescence in situ hybridization (FISH) analyses were performed in 8 patients with Turner syndrome and 45,X mosaic karyotypes to determine the origin and structure of the marker chromosome in the second cell line. Our data showed that markers were Y-derived in 2 patients and X-derived in the remaining 6 patients. We were also able to determine the breakpoints in the two Y chromosomes. The use of cytogenetic and molecular techniques allowed us to establish unequivocally the origin, X or Y, of the marker chromosomes in the 8 patients with Turner phenotype. This study illustrates the power of resolution and utility of combined cytogenetic and molecular approaches in some clinical cases.

Analysis of sex chromosome aneuploidy in 41 patients with Turner syndrome: a study of 'hidden' mosaicism

We performed a genetic study of sex chromosome mosaicism in 41 Turner syndrome patients. The investigation was carried out in four phases: cytogenetics (G-banding), FISH, PCR for SRY in all 41 cases, and sequencing of the SRY gene in the 2 patients with the Y chromosome. The application of classical alpha-satellite probes (CEP-X and CEP-Y), painting probes (WCP-X and WCP-Y) and also XIST, DXZ4 and two subchromosomal painting libraries (SCPL 116 and SCPL102) covering the short and the long arm of the X chromosome, respectively, allowed us to find new mosaic cell lines (mosaicism) in 37 out of 41 patients; only 4 patients were defined as 45,X non-mosaic. The most frequent hidden mosaic was 45,X/46,XX in 32% of the cases; the presence of isochromosomes comprised 25% and markers 5%. The patients who had been previously diagnosed as mosaics displayed a higher complexity in their karyotypes due to the presence of new cell lines. The Y chromosome and the SRY gene were present in blood and ovarian tissue in 2 patients with karyotypes 45,X/46,XY and 45,X/46,X,idic(Ynf). In both patients, the sequencing of the SRY gene confirmed a nucleotide sequence identical to that of a control male. Our results support the hypothesis of 'the necessity of mosaicism for survival', and thus, a mitotic origin for this syndrome.

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

OBJECTIVE

The frequency of gonadoblastoma is high in patients with Turner's syndrome bearing cells with Y or partial Y-chromosome. About 60% of patients with Turner's syndrome have a 45,X karyotype. In 30% of them a Y-sequence is disclosed by DNA analysis. To identify patients at risk of developing gonadoblastoma, a PCR based assay with SRY, ZFY and DYZ3 specific primers was carried out to detect different Y-sequences in the DNA of peripheral lymphocytes from patients with Turner's syndrome.

DESIGN AND PATIENTS

Peripheral blood karyotypes from 36 patients with Turner's syndrome were studied. Patients with proven Y-chromosomal material were excluded. Genomic DNA was extracted from peripheral blood. SRY and ZFY genes and DYZ3 repetion of Y-chromosome were amplified by PCR. Patients with clinical signs of hyperandrogenism or with positive Y-sequences by PCR underwent gonadectomy. The gonadal tissues were examined for Y-sequences using PCR, morphology and immunohistochemical study.

MEASUREMENTS

Turner's syndrome and signs of hyperandrogenism were evaluated both clinically and through laboratory tests. Haematoxylin and eosin staining was employed in gonadal morphology studies. The presence of testosterone was detected by immunohistochemistry using a monoclonal antibody.

RESULTS

Two patients who had Y-positive blood samples and three hyperandrogenic (2 hirsutes, 1 virilized) Y-negatives underwent gonadectomy. PCR was carried out on their gonadal tissue. The tissue from the two patients without hyperandrogenism was Y-positive. The gonadal tissue from the three hyperandrogenics was Y-negative. Gonadal morphology disclosed hilus cell hyperplasia in the 3 hyperandrogenic Y-negatives and in one Y-positive patient; stromal luteoma and hyperthecosis in the virilized patient, cystadenofibroma in one hirsute patient and gonadoblastoma in one Y-positive. Testosterone was detected immunohistochemically in the hilus cell hyperplasia, stromal luteoma and hyperthecosis found in the hyperandrogenic patients.

CONCLUSIONS

The molecular study was sensitive and useful in the evaluation of patients at risk of developing gonadoblastoma. Other nontumour, gonadotrophin-dependent and Y-independent mechanisms which deserve the same medical approach may be involved in the genesis of hyperandrogenic signs in Turner's syndrome.

Detection and incidence of cryptic Y chromosome sequences in Turner syndrome patients

The presence of Y chromosome sequences in Turner syndrome (TS) patients may predispose them to gonadoblastoma formation with an estimated risk of 15-25%. The aim of this study was to determine the presence and the incidence of cryptic Y chromosome material in the genome of TS patients. The methodology involved a combination of polymerase chain reaction (PCR) and nested PCR followed by Southern blot analysis of three genes the sex determining region Y (SRY), testis specific protein Y encoded (TSPY) and RNA binding motif protein (RBM) (previously designated as YRRM) and nine additional STSs spanning all seven intervals of the Y chromosome. The methodology has a high sensitivity as it detects one 46,XY cell among 10(5) 46,XX cells. Reliability was ensured by taking several precautions to avoid false positive results. We report the results of screening 50 TS patients and the identification of cryptic Y chromosome material in 12 (24%) of them. Karyotypes were divided in four groups: 5 (23.8%) patients out of the 21 TS patients which have the 45,X karyotype (group A) also have cryptic Y sequences; none (0%) of the 7 patients who have karyotypes with anomalies on one of the X chromosomes have Y mosaicism (group B); 1 (6.3%) of the 16 patients with a mosaic karyotype have Y material (group C); and 6 (100%) out of 6 patients with a supernumerary marker chromosome (SMC) have Y chromosome sequences (group D). Nine of the 12 patients positive for cryptic Y material were recalled for a repeat study. Following new DNA extraction, molecular analysis was repeated and, in conjunction with fluorescent in situ hybridization (FISH) analysis using the Y centromeric specific probe Yc-2, confirmed the initial positive DNA findings. This study used a reliable and sensitive methodology to identify the presence of Y chromosome material in TS patients thus providing not only a better estimate of a patient's risk in developing either gonadoblastoma or another form of gonadal tumor but also the overall incidence of cryptic Y mosaicism.

Morbidity in Turner syndrome

Turner syndrome afflicts approximately 50 per 100,000 females and is characterized by retarded growth, gonadal dysgenesis, and infertility. Much attention has been focused on growth and growth promoting therapies, while less is known about the natural course of the syndrome, especially in adulthood. We undertook this study to assess the incidence of diseases relevant in the study of Turner syndrome. The study period was from January 1, 1984 to December 31, 1993, and the study base was all women living in Denmark during the study period. We used data from the Danish Cytogenetic Central Register and the Danish National Registry of Patients to assess morbidity. This study supports several earlier studies reporting increased morbidity and confirms results of a recent study on cancer in Turner syndrome. Women with Turner syndrome seem to have an increased incidence of fractures, osteoporotic fractures in adulthood, and non-osteoporotic fractures in childhood. Furthermore, diabetes mellitus, both NIDDM and IDDM, was found with a markedly increased incidence in Turner syndrome, as well as ischemic heart disease, hypertension, and stroke. The risk of cancer, except cancer of the large bowel, does not seem to be elevated in Turner syndrome. Our data suggest that patients with Turner syndrome are extraordinarily prone to abnormalities constituting the metabolic syndrome (e.g., hypertension, dyslipidaemia, NIDDM, obesity, hyperinsulinemia and hyperuricemia). The present data may help to explain the decreased life span found in patients with Turner syndrome.

Coexistence of hereditary angioedema and Turner's syndrome

A 34-year-old woman presented to the out-patient clinic with angioedema and type II hereditary angioedema was confirmed immunologically. She also volunteered she had never had a menstrual period and physical examination identified several features of Turner's syndrome. A mosaic karyotype with XY and XO was found on chromosomal analysis and gonadectomy was performed in view of the high risk of gonadoblastoma. After commencing oestrogen at physiological replacement doses, the patient experienced a marked deterioration in both the severity and frequency of angioedema attacks. Coexistence of hereditary angioedema and Turner's syndrome has not previously been reported and this case highlights the detrimental C1 inhibitor level lowering effect of oestrogen in hereditary angioedema.

PCR and FISH analysis of a ring Y chromosome

A newborn male infant presented with midshaft hypospadias, chordee, and undescended left testis. Both gonads lacked the tunica albuginea and appeared to be adjacent to structures resembling fallopian tubes. On biopsy, there was marked dysgenesis of both gonads, with a paucity of testicular tubules and foci of ovarian-like stroma. Peripheral blood karyotype was 46,X,mar(Y) [39]/45,X [5]. Right gonadal biopsy material showed the same mosaicism but with a higher proportion of 45,X cells (46%). PCR and FISH analyses with primers/probes from different Yp, Yq, and Ycen loci defined the structure of the marker Y as a probable complex ring with breakpoints in Yq11.21 (very close to the centromere) and in Yp11.32 (the pseudoautosomal region). Based on the phenotype and the laboratory findings, the prognosis given to the patient was for short stature and azoospermia without an increased risk for gonadoblastomas.

Supernumerary marker chromosomes (SMCs) in Turner syndrome are mostly derived from the Y chromosome

DNA and FISH (fluorescence in situ hybridization) analysis were carried out in 12 patients with stigmata of Turner syndrome to determine whether the Supernumerary Marker Chromosome (SMC) found cytogenetically in each of these patients was derived from the Y chromosome. The presence of a Y chromosome in these patients may predispose them to develop gonadoblastoma. PCR-Southern blot analysis, followed by FISH, was used to detect the presence of Y chromosome material. The Sex determining Region Y (SRY), Testis Specific Protein Y-encoded (TSPY) and Y-chromosome RNA Recognition Motif (YRRM) genes, which map at Yp11.31, Yp11.1-11.2 and Yp11.2/Yq11.21-11.23, respectively, were selected as markers, because they span the whole Y chromosome, and more importantly, they are considered to be involved in the development of gonadoblastoma. It was shown that in 12 patients, all of whom had an SMC, the SMC of 11 was derived from the Y chromosome. Furthermore, the presence of the SRY, TSPY and YRRM gene sequences was determined and FISH analysis confirmed the Y origin of the SMCs. The methodology described in this report is a rapid, reliable and sensitive approach which may be easily applied to determine the Y origin of an SMC carried in Turner syndrome. The identification of an SMC is important for the clinical management and prognostic counseling of these patients with Turner syndrome.

Cytogenetic and molecular findings in patients with Turner's syndrome stigmata

Cytogenetic and DNA analysis in 12 people with stigmata of Turner's syndrome was carried out. Cytogenetic analysis of these patients showed two subjects with 46,X, i(Xq) karyotypes, one with 45,X/46,X, i(Xq), one with 46,X,t(X;Y), and eight with 45,X/46,X,mar. Molecular analysis of DNA samples was performed in nine out of 12 patients with marker chromosomes. PCR analysis with oligoprimers specific for SRY, DYZ1, or DYZ3 loci identified Y chromosome material in five patients in the latter group. The X chromosome origin of the marker chromosome was proved by FISH technique with biotin labelled pericentromeric X chromosome specific probe in four other patients. These results show that patients with a number of Turner's syndrome stigmata usually do not have a typical XO karyotype but have some structural chromosomal aberrations involving the X or Y chromosomes. Combined application of cytogenetic, molecular cytogenetic (FISH), and PCR techniques significantly improves the precision of marker chromosome identification and thus might be of practical importance for the proper management and treatment of affected patients. Peculiarities of pathological manifestations of different karyotypes bearing structural abnormalities of the X or Y chromosomes in patients with Turner's syndrome stigmata, as well as feasible genetic mechanisms of sex determination and differentiation abnormalities in these subjects, are briefly discussed.

Parental origin of the X chromosome, X chromosome mosaicism and screening for "hidden" Y chromosome in 45,X Turner syndrome ascertained cytogenetically

Our study confirms the finding that about 85% of X chromosomes in Turner girls are maternally derived. A new observation is the detection of a high frequency of mosaicism (15%) in Turner girls who by cytogenetic analysis were thought to have a pure 45,X karyotype. DNA examination of the material was done by hybridization with digoxigenin labelled, non-radioactive probes, and PCR products for microsatellite analysis were run on polyacrylamide gels. We screened for the presence of "hidden" Y chromosome mosaicism, using the primers SRY, ZFY, DYZ3, DYZ1 and DYS132. Contrary to other reports using the PCR technique to unravel "hidden" Y chromosome mosaics, we did not find any positive cases. A precise technical protocol for these new techniques is given, and the advantages are discussed.

Phenotype/karyotype correlations of Y chromosome aneuploidy with emphasis on structural aberrations in postnatally diagnosed cases

Over 600 cases with a Y aneuploidy (other than non-mosaic 47,XYY) were reviewed for phenotype/karyotype correlations. Except for 93 prenatally diagnosed cases of mosaicism 45,X/46,XY (79 cases), 45,X/47,XYY (8 cases), and 45,X/46,XY/47,XYY (6 cases), all other cases were ascertained postnatally. Special emphasis was placed on structural abnormalities. This review includes 11 cases of 46,XYp-; 90 cases of 46,XYq- (52 cases non-mosaic; 38 cases 45,X mosaic); 34 cases of 46,X,r(Y) (9 cases non-mosaic and 25 cases 45,X mosaic); 8 cases of 46,X,i(Yp) (4 non-mosaic and 4 mosaic with 45,X); 12 cases of 46,X,i(Yq) (7 non-mosaic and 5 mosaic); 44 cases of 46,X,idic(Yq); 80 cases of 46,X, idic(Yp) (74 cases had breakpoints at Yq11 and 6 cases had breakpoints at Yq12); 130 cases of Y/autosome translocations (50 cases with a Y/A reciprocal translocation, 20 cases of Y/A translocation in 45,X males, 60 cases of Y/DP or Y/Gp translocations); 52 cases of Y/X translocations [47 cases with der(X); 4 cases with der(Y), and 1 case with 45,X with a der(X)], 7 cases of Y/Y translocations; 151 postnatally diagnosed cases of 45,X/46,XY; 14 postnatally diagnosed cases of 45,X/47,XYY; 18 cases of 45,X/46,XY/47,XYY; and 93 aforementioned prenatally diagnosed cases with a 45,X cell line. It is clear that in the absence of a 45,X cell line, the presence of an entire Yp or a region of it including SRY would lead to a male phenotype in an individual with a Y aneuploidy, whereas the lack of Yp invariably leads to a female phenotype with typical or atypical Ullrich-Turner syndrome (UTS). Once there is a 45,X cell line, regardless of whether there is Yp, Yq, or both Yp and Yq, or even a free Y chromosome in other cell line, there is an increased chance for that individual to be a phenotypic female with UTS manifestations or to have ambiguous external genitalia. This review once again shows a major difference in reported phenotypes between postnatally and prenatally diagnosed cases of 45,X/46,XY, 45,X/47,XYY, and 45,X/46,XY/47,XYY mosaicism. It appears that ascertainment bias can explain the fact that all known patients with postnatal diagnosis are phenotypically abnormal, while over 90% of prenatally diagnosed cases are reported to have a normal male phenotype. Further elucidation of major Y genes and their clinical significance can be expected in the rapidly expanding gene mapping projects. More, consequently better, phenotype/karyotype correlations can be anticipated at both the cytogenetic and the molecular level.