Functional and regulatory aspects of oxidative stress response in X monosomy.

The partial/complete loss of one X chromosome in a human female leads to Turner syndrome (TS). TS individuals display a range of phenotypes including short stature, osteoporosis, ovarian malfunction, diabetes, and thyroid dysfunction. Epigenetic factors and regulatory networks are distinctly different in X monosomy (45, X). In a lifetime, an individual is exposed to a variety of stress conditions. To study whether X monosomy cells display a differential response upon exposure to mild stress as compared to normal 46, XX cells and whether this may contribute to various co-morbidities in aneuploid individuals, we have carried out a transcriptomic analysis of human fibroblasts 45, X and 46, XX after exposure to mild oxidative stress. Under these conditions, over 350 transcripts were seen to be differentially expressed in 45, X and 46, XX cells. Pathways associated with oxidative stress were differentially expressed highlighting the differential regulation of genes and associated phenotypes. It could be seen that X monosomy cells are more susceptible to oxidative stress as compared to normal cells and have altered molecular pathways both in normal conditions and also upon exposure to mild oxidative stress. To explore this aspect in detail, we have mapped the expressions of transcription factors (TFs) in 45, X and 46, XX cells. The network of transcription activating factors is differentially regulated in 45, X and 46, XX cells under stress exposure. It is tempting to speculate that the altered ability of 45, X (Turner) cells to respond to stress may play a significant role in the physiological function and altered phenotypes in Turner syndrome.

Fragile X prenatal analyses show full mutation females at high risk for mosaic Turner syndrome: fragile X leads to chromosome loss.

The fragile X mutation is an expansion of a CGG triplet repeat in the 5' untranslated region of the FMR1 gene. Expansion to >200 repeats (the "full mutation") silences FMR1 transcription and leads to the fragile X mental retardation syndrome in males and in some females. It also affects the structure of the mitotic chromosome as evidenced by a folate sensitive fragile site. Isolated cases of 45,X/46,XX (mosaic Turner syndrome) in full mutation females have been reported but an increased prevalence was not apparent from these reports. PCR and Southern analysis of the CGG repeat in 423 prenatal female samples identified 106 full mutation cases. Surprisingly five of these had 45,X/4,6XX mosaicism while none of the other 317 female fetuses did. In two of the five cases >or=50% of the cells were reported to be 45,X and in the other three,

Female pseudohermaphroditism due to classical 21-hydroxylase deficiency and insulin resistance in a girl with Turner syndrome.

We report five-year-old girl with female pseudohermaphroditism due to classical form of 21-hydroxylase deficiency associated with Turner's syndrome (45,X/46,XX) and insulin resistance. She had clitoromegaly since birth, but Turner's syndrome and 21-hydroxylase deficiency were diagnosed incidentally at one and five years of age, respectively. Moreover, we determined insulin resistance, which resolved following corticosteroid therapy for disease. We regard the rare combination as a coincidental occurrence. We stress that adrenal function should be assessed, at least in the presence of clitoral enlargement, in patients with Turner's syndrome, particularly if their karyotype does not contain a Y chromosome. We conclude that chronic hypersecretion of androgen precursors due to an inborn error of metabolism can induce a reduction in insulin sensitivity. Improvement in insulin resistance after treatment of hyperandrogenism has not been previously reported.

Twins discordant for 46,XX gonadal dysgenesis.

This case report describes twin sisters, one with rudimentary streak gonads and the other with normal ovarian function. Both siblings had normal 46, XX karyotypes, and zygosity testing indicated that they were identical twins. Discordance of identical twins for 46, XX pure gonadal dysgenesis suggests that environmental factors may be a causative factor in some of the karyotypically normal 46,XX forms of gonadal dysgenesis.

Gestación en paciente con insuficiencia ovárica primaria secundaria a mosaicismo de Síndrome de Turner / Pregnancy in a patient with primary ovarian insufficiency owing to a mosaicism of Turner Syndrome

RESUMEN La Insuficiencia Ovárica Primaria se define por una amenorrea secundaria de al menos cuatro meses de duración, deficiencia de esteroides sexuales (estradiol) y altas concentraciones séricas de hormona folículoestimulante (FSH) con al menos un mes de diferencia entre estas determinaciones, en mujeres menores de 40 años. Es una causa insidiosa de infertilidad pero en algunas ocasiones es transitoria y permite una gestación espontánea. El Síndrome de Turner es un trastorno genético caracterizado por la pérdida o anomalías estructurales de un cromosoma X y que afecta a 1 de cada 2.500 mujeres nacidas vivas. Las manifestaciones clínicas varían entre pacientes, pero generalmente se relaciona con talla baja, coartación aórtica, disgenesia gonadal e insuficiencia ovárica primaria. Las técnicas de reproducción asistida como la criopreservación de ovocitos y de tejido ovárico, la maduración in vitro o la donación de ovocitos ofrecen opciones reproductivas en aquellos casos en los que no se produzca un embarazo espontáneo.

ABSTRACT Primary Ovarian Insufficiency is considered a secondary amenorrhea of at least four months duration, sex steroid deficiency (estradiol) and high serum concentrations of follicle stimulating hormone (FSH) with at least one month difference between these determinations, in women under 40 years. It is an insidious cause of infertility but sometimes it is transient and allows a spontaneous pregnancy. Turner syndrome is a genetic disorder characterized by the loss or structural abnormalities of an X chromosome that affects 1 in 2,500 women born alive. Clinical manifestations vary among patients, but it is usually associated with short stature, aortic coarctation, gonadal dysgenesis, and primary ovarian failure. Assisted reproduction techniques such as cryopreservation of oocytes and ovarian tissue, in vitro maturation or oocyte donation offer reproductive options in those cases in which there is no spontaneous pregnancy.

Síndrome de Turner: nuestra experiencia en la creación del Registro Institucional y de la Unidad Interdisciplinaria en el Hospital Italiano de Buenos Aires: un primer paso para el mejor seguimiento / Turner syndrome: our experience in the creation of the Registry Institutional and Interdisciplinary Unit at the Italian Hospital of Buenos Aires: a first step to the best follow-up

El síndrome de Turner (ST) resulta de la ausencia completa o parcial del segundo cromosoma sexual en fenotipos femeninos. Tiene una incidencia de 1:2000- 2500 nacidas vivas. Recién en la última década se ha puesto atención a la salud de las adultas con ST. La mortalidad es 3 veces superior respecto de la población general debido al riesgo de disección aórtica por anomalías cardiovasculares estructurales y aterosclerosis vinculada a hipertensión arterial, diabetes, dislipidemia y obesidad. También presentan elevada prevalencia de enfermedades autoinmunitarias. Objetivo: evaluar la calidad del seguimiento clínico de pacientes adultas con ST, comparando los controles de salud preconformación y posconformación del Registro y de la Unidad Interdisciplinaria. En el año 2017 fuimos convocados para integrar el Programa de Enfermedades Raras del Hospital Italiano de Buenos Aires. A partir de la creación del Registro Institucional y del equipo multidisciplinario obtuvimos mejoría significativa en los controles por las especialidades de cardiología, endocrinología y otorrinolaringología, en los controles bioquímicos del metabolismo lipídico, hidrocarbonado, hepatograma, TSH y anticuerpos para celiaquía e imágenes cardiovasculares y densitometría ósea. En conclusión, el seguimiento sistematizado e institucional, mediante el Registro y la creación de la Unidad Interdisciplinaria de Síndrome de Turner, permitió encontrar las falencias del sistema de atención y optimizar el seguimiento de esta población. (AU)

Turner syndrome (TS) results from the complete or partial absence of the second sex chromosome in female phenotypes. It has an incidence of 1: 2000-2500 girls born alive. Only in the last decade has been paid attention to the health of adults women with TS. Mortality is 3 times higher than in the general population due to the risk of aortic dissection cause to structural cardiovascular anomalies and atherosclerosis related to hypertension, diabetes, dyslipidemia and obesity. They also have a high prevalence of autoimmune diseases. Until nowadays in Argentina do not exist a national registry of this disease that complies with the international follow-up recommendations for these patients. We proposed to develop the institutional register at 2014 and a multidisciplinary team was created to care and follow up girls and women with TS during 2015. It was indexed to Italian Hospital of Buenos Aires' Rare Diseases Program since 2017. After the creation of the institutional registry and the multidisciplinary team we obtained a significant improvement in cardiology, endocrinology and otorhinolaryngology schedule visits, in lipids and hydrocarbon metabolism, liver, thyroid and celiac diseases biochemical controls and in the performance of cardiovascular MNR and bone densitometry. In conclusion, the systematized and institutional follow-up, through the registry and the creation of the Interdisciplinary Unit of Turner Syndrome, allowed us to find the flaws of the care system and to optimize the follow up of this population. (AU)

Turner syndrome and metabolic derangements: another example of fetal programming.

BACKGROUND AND AIM: Turner syndrome (TS) patients have an increased risk of weight gain and metabolic syndrome. To date, it is unknown what factors are involved in this metabolic process, even though it is recognized that TS patients are frequently born small-for-gestational age. The aim of this study was to evaluate the correlation between lipid and glucose profiles with being overweight and birth weight and length in TS patients. STUDY DESIGN: This was a cross-sectional study. SUBJECTS AND OUTCOME MEASURES: Serum glucose, insulin (HOMA-IR), total cholesterol, and triglycerides were measured in 64 patients with TS. Data regarding birth weight and length and current body mass index (BMI) were also evaluated. RESULTS: Total cholesterol showed a significant negative correlation with birth weight and a positive correlation with BMI; triglycerides showed significant negative correlation with birth weight and length and a positive correlation with BMI; and HOMA-IR showed a significant negative correlation with birth weight and length. Low birth weight and a high BMI were predictive for 28% of total cholesterol and triglycerides; and low birth weight for 22% of HOMA-IR. CONCLUSIONS: Lipid profile was correlated with a high current BMI and low birth weight and length in TS patients and glucose profile only with low birth weight. Thus far, growth retardation may play a role in metabolic derangements in this group of patients, being considered another example of fetal programming.

The role of SRY mutations in the etiology of gonadal dysgenesis in patients with 45,X/46,XY disorder of sex development and variants.

BACKGROUND: The potential involvement of SRY in abnormal gonadal development in 45,X/46,X,der(Y) patients was proposed following the identification of SRY mutations in a few patients with Turner syndrome (TS). However, its exact etiological role in gonadal dysgenesis in patients with Y chromosome mosaicisms has not yet been clarified. AIMS: it was the aim of this study to screen for allelic variation in SRY in a large cohort of patients with disorders of sex development due to chromosomal abnormalities with 45,X/46,X,der(Y) karyotype. PATIENTS: twenty-seven patients, 14 with TS and 13 with mixed gonadal dysgenesis (MGD), harboring 45,X/46,X,der(Y) karyotypes were selected. METHODS: Genomic DNA was extracted from peripheral blood leukocytes of all patients and from gonadal tissue in 4 cases. The SRY coding region was PCR amplified and sequenced. RESULTS: We identified only 1 polymorphism (c.561C→T) in a 45,X/46,XY MGD patient, which was detected in blood and in gonadal tissue. CONCLUSION: our results indicate that mutations in SRY are rare findings in patients with Y chromosome mosaicisms. Therefore, a significant role of mutated SRY in the etiology of gonadal dysgenesis in patients harboring 45,X/46,XY karyotype and variants seems very unlikely.

Síndrome de Turner e polimorfismo genético: uma revisão sistemática / Turner syndrome and genetic polymorphism: a systematic review

Objetivo:Apresentar os principais resultados dos estudos que investigaram polimorfismos genéticos em síndrome de Turner, bem como sua associação com alguns sinais clínicos e etiologia desse distúrbio cromossômico.Fontes de dados:Revisão bibliográfica feita no PubMed, sem limite de período, com os seguintes termos: Turner syndrome and genetic polymorphism. Foram identificados 116 artigos e, de acordo com os critérios de inclusão e exclusão, 17 foram selecionados para leitura.Síntese dos dados:Os polimorfismos investigados em pacientes com síndrome de Turner estavam relacionados com déficit de crescimento, que causou baixa estatura, densidade mineral óssea baixa, autoimunidade e anomalias cardíacas, que podem estar presentes com frequências significativas nas pacientes. Também foi verificado o papel dos polimorfismos de único nucleotídeo (SNPs) na etiologia da síndrome de Turner, ou seja, na não disjunção cromossômica.Conclusões:Os polimorfismos genéticos parecem estar associados à síndrome de Turner. Entretanto, por conta dos poucos estudos publicados e dos achados contraditórios, pesquisas em diferentes populações são necessárias para esclarecer o papel dessas variantes genéticas para os sinais clínicos e a etiologia do distúrbio cromossômico.

Objective:To present the main results of the literature on genetic polymorphisms in Turner syndrome and their association with the clinical signs and the etiology of this chromosomal disorder.Data sources:The review was conducted in the PubMed database without any time limit, using the terms Turner syndrome and genetic polymorphism. A total of 116 articles were found, and based on the established inclusion and exclusion criteria 17 were selected for the review.Data synthesis:The polymorphisms investigated in patients with Turner syndrome were associated with growth deficit, causing short stature, low bone mineral density, autoimmunity and cardiac abnormalities, which are frequently found in patients with Turner syndrome. The role of single nucleotide polymorphisms in the etiology of Turner syndrome, i.e., in chromosomal nondisjunction, was also confirmed.Conclusions:Genetic polymorphisms appear to be associated with Turner syndrome. However, in view of the small number of published studies and their contradictory findings, further studies in different populations are needed in order to clarify the role of genetic variants in the clinical signs and etiology of the Turner syndrome.

Patología nefrourológica en niñas con síndrome de Turner / Nephrourologic pathology in girls with Turner syndrome

Las malformaciones nefrourológicas en el síndrome de Turner son frecuentes, por lo que su diagnóstico y seguimiento son importantes para disminuir la morbilidad de esta entidad. El objetivo de este trabajo retrospectivo fue analizar la patología nefrourológica en 72 niñas con síndrome de Turner atendidas entre 1989 y 2008 en el Hospital Garrahan. La prevalencia de patología nefrourológica fue del 33% (24 pacientes). Predominaron las anomalías del sistema urinario aisladas (10 pacientes, 42%) o asociadas a malformaciones renales (9 pacientes, 37%); 5 pacientes (21%) tuvieron anomalías estructurales renales aisladas. El 50% presentó complicaciones (8 infección urinaria, 2 proteinuria y 2 hipertensión arterial).

Nephrourologic malformations in Turner syndrome are frequent, its diagnosis and follow-up is important in order todiminish the morbidity of this disease. The aim of this retrospective study was to analyze the nephrourologic pathologyin 72 girls with Turner syndrome followed between 1989 and 2008 at Garrahan Hospital. The prevalence of nephrourologic involvement was 33% (24 patients). The most frequent findings were urinary system malformations, isolated (10 pacientes,42%) or associated with renal malformations (9 patients, 37%); 5 patients (21%) had only renal malformations. Fifty percent of patients developed complications (8 urinary tractinfection, 2 proteinuria and 2 arterial hypertension); however, none progressed to chronic renal failure. The prevalence of nephrourologic involvement was 33% and a half of these girls developed complications, our findings show the need of routine nephrological follow-up of girls with Turner syndrome and nephrourologic malformations.