scholarly journals A Review of Recent Developments in Turner Syndrome Research

2021 ◽  
Vol 8 (11) ◽  
pp. 138
Author(s):  
Allen C. Huang ◽  
Susan B. Olson ◽  
Cheryl L. Maslen

Turner syndrome is a rare disorder resulting from complete or partial loss of the second sex chromosome. Common manifestations include delayed growth, premature ovarian failure, congenital heart defects, endocrine disorders, lymphedema, and webbed neck. People with Turner syndrome have significantly increased mortality risk primarily due to cardiovascular abnormalities. The mechanisms that lead to these defects are not completely understood and are obscured by the significant variability of both karyotype and phenotype without consistent correlation between the two. This paper presents a review of the recent literature surrounding the symptoms, mechanisms, diagnosis, and treatment of Turner syndrome with a focus on cardiovascular manifestations. With technological advancements in genetics, the molecular processes of Turner syndrome have begun to be dissected. Certain genes on the X chromosome that typically escape inactivation have been implicated in both specific manifestations and broader risk categories. Recently identified genome-wide epigenetic changes may help explain the variability in presentation. It remains unclear as to how the combination of these factors results in the overall clinical picture, but advances in genomic, genetic, epigenetic, and -omics technology hold promise for providing insights that will improve the medical management of individuals with Turner syndrome.

2017 ◽  
Vol 5 ◽  
pp. 2050313X1668791 ◽  
Author(s):  
Evan Los ◽  
Hayley Baines ◽  
Ines Guttmann-Bauman

Most cases of Van der Woude syndrome are caused by a mutation to interferon regulatory factor 6 on chromosome 1. Turner syndrome is caused by complete or partial absence of the second sex chromosome in girls. We describe a unique case of the two syndromes occurring concurrently though apparently independently in a girl with Van der Woude syndrome diagnosed at birth and Turner syndrome at 14 years 9 months. Short stature was initially misattributed to Van der Woude syndrome and pituitary insufficiency associated with clefts before correctly diagnosing Turner syndrome. We discuss the prevalence of delayed diagnosis of Turner syndrome, the rarity of reports of concurrent autosomal chromosome mutation and sex chromosome deletion, as well as the need to consider the diagnosis of Turner syndrome in all girls with short stature regardless of prior medical history.


2019 ◽  
Vol 8 (11) ◽  
pp. 1483-1492
Author(s):  
Elin Kahlert ◽  
Martina Blaschke ◽  
Knut Brockmann ◽  
Clemens Freiberg ◽  
Onno E Janssen ◽  
...  

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.


Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xuqi Chen ◽  
Rebecca McClusky ◽  
Yuichiro Itoh ◽  
Karen Reue ◽  
Arthur P. Arnold

Abstract Three different models of MF1 strain mice were studied to measure the effects of gonadal secretions and sex chromosome type and number on body weight and composition, and on related metabolic variables such as glucose homeostasis, feeding, and activity. The 3 genetic models varied sex chromosome complement in different ways, as follows: 1) “four core genotypes” mice, comprising XX and XY gonadal males, and XX and XY gonadal females; 2) the XY* model comprising groups similar to XO, XX, XY, and XXY; and 3) a novel model comprising 6 groups having XO, XX, and XY chromosomes with either testes or ovaries. In gonadally intact mice, gonadal males were heavier than gonadal females, but sex chromosome complement also influenced weight. The male/female difference was abolished by adult gonadectomy, after which mice with 2 sex chromosomes (XX or XY) had greater body weight and percentage of body fat than mice with 1 X chromosome. A second sex chromosome of either type, X or Y, had similar effects, indicating that the 2 sex chromosomes each possess factors that influence body weight and composition in the MF1 genetic background. Sex chromosome complement also influenced metabolic variables such as food intake and glucose tolerance. The results reveal a role for the Y chromosome in metabolism independent of testes and gonadal hormones and point to a small number of X–Y gene pairs with similar coding sequences as candidates for causing these effects.


Author(s):  
C. Clark ◽  
H. Klonoff ◽  
M. Hayden

ABSTRACT:Regional cerebral glucose metabolism was examined in females with Turner syndrome, a sex chromosome abnormality. Previous studies have found a visual/spatial cognitive anomaly in these women but, to date, no abnormalities in brain structure or function have been associated with the condition. In the present study, decreases in regional metabolism were found in the occipital and parietal cortex. The involvement of the occipital cortex, although consistent with the observed cognitive anomalies, has not been suggested previously as an area dysfunction. Because the occipital cortex is a primary sensory cortex, the reduction of glucose metabolism in the parietal cortex may reflect a lack of innervation from the occipital cortex. Besides insight into the functional specialization of the brain, these findings are also consistent with previous reports on animals regarding the effects of estrogen in brain maturation.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Carolyn Bondy

The past decade produced important advances in molecular genetic techniques potentially supplanting the traditional cytogenetic diagnosis of Turner syndrome (TS). Rapidly evolving genomic technology is used to screen 1st trimester pregnancies for sex chromosomal anomalies including TS, and genomic approaches are suggested for the postnatal diagnosis of TS. Understanding the interpretation and limitations of new molecular tests is essential for clinicians to provide effective counseling to parents or patients impacted by these tests. Recent studies have advanced the concept that X chromosome genomic imprinting influences expression of the Turner phenotype and contributes to gender differences in brain size and coronary disease. Progress in cardiovascular MRI over the past decade has dramatically changed our view of the scope and criticality of congenital heart disease in TS. Cardiac MRI is far more effective than transthoracic echocardiography in detecting aortic valve abnormalities, descending aortic aneurysm, and partial anomalous pulmonary venous return; recent technical advances allow adequate imaging in girls as young as seven without breath holding or sedation. Finally, important developments in the area of gynecological management of girls and young women with TS are reviewed, including prognostic factors that predict spontaneous puberty and potential fertility and recent practice guidelines aimed at reducing cardiovascular risk for oocyte donation pregnancies in TS.


Author(s):  
Francisco Álvarez-Nava

Turner syndrome (TS) is a chromosomal disorder that is caused by a missing or structurally abnormal second sex chromosome. Subjects with TS are at an increased risk of developing intrauterine growth retardation, low birthweight, short stature, congenital heart diseases, infertility, obesity, dyslipidemia, hypertension, insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular diseases (stroke and myocardial infarction). The underlying pathogenetic mechanism of TS is unknown. The assumption that X chromosome-linked gene haploinsufficiency is associated with the TS phenotype is questioned since such genes have not been identified. Thus, other pathogenic mechanisms have been suggested to explain this phenotype. Morphogenesis encompasses a series of events that includes cell division, the production of migratory precursors and their progeny, differentiation, programmed cell death and integration into organs and systems. The precise control of the growth and differentiation of cells is essential for normal development. The cell cycle frequency and the number of proliferating cells are essential in cell growth. 45,X cells have a failure to proliferate at a normal rate, leading to a decreased cell number in a given tissue during organogenesis. A convergence of data indicates an association between a prolonged cell cycle and the phenotypical features in Turner syndrome. This review aims to examine old and new findings concerning the relationship between a prolonged cell cycle and TS phenotype. These studies reveal a diversity of phenotypic features in TS that could be explained by reduced cell proliferation. The implications of this hypothesis for our understanding of the TS phenotype and its pathogenesis are discussed. It is not surprising that 45,X monosomy leads to cellular growth pathway dysregulation with profound deleterious effects on both embryonic and later stages of development. The prolonged cell cycle could represent the beginning of the pathogenesis of TS, leading to a series of phenotypic consequences in embryonic/fetal, neonatal, pediatric, adolescence, and adulthood life.


2011 ◽  
Vol 30 (2-3) ◽  
pp. 77-87 ◽  
Author(s):  
Ulrike Schmidt ◽  
Florian Holsboer ◽  
Theo Rein

Development of psychiatric diseases such as posttraumatic stress disorder (PTSD) invokes, as with most complex diseases, both genetic and environmental factors. The era of genome-wide high throughput technologies has sparked the initiation of genotype screenings in large cohorts of diseased and control individuals, but had limited success in identification of disease causing genetic variants. It has become evident that these efforts at the genomic level need to be complemented with endeavours in elucidating the proteome, transcriptome and epigenetic profiles. Epigenetics is attractive in particular because there is accumulating evidence that the lasting impact of adverse life events is reflected in certain covalent modifications of the chromatin.In this review, we outline the characteristics of PTSD as a stress-related disease and survey recent developments revealing epigenetic aspects of stress-related disorders in general. There is also increasing direct evidence for gene programming and epigenetic components in PTSD. Finally, we discuss treatment options in the light of recent discoveries of epigenetic mechanisms of psychotropic drugs.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Siddharth Prakash ◽  
Michael Silberbach ◽  
Federico Asch ◽  
Giuseppe Limongelli ◽  
Hector Michelena ◽  
...  

Introduction: The prevalence of bicuspid aortic valves (BAV) is enriched thirty-fold in women with Turner Syndrome (TS) in comparison with the general population. Hypothesis: Common autosomal variants influence the development of BAV in TS women, who may be uniquely sensitized to these variants by the loss of one X chromosome. We sought to identify autosomal BAV susceptibility genes in a cohort of TS women (average age 30 years, 38% BAV, 18% coarctation). Methods: A total of 106 TS women of European ancestry with BAV and 173 TS women with tricuspid aortic valves were genotyped on Illumina Omni-Express arrays. Valve phenotypes were determined by independent review of echocardiograms from the enrolling sites. Tests of association were performed using logistic regression without adjustment for covariates and were summarized in a meta-analysis. Results: Xp dosage was inversely and quantitatively associated with BAV status (P=0.02). Large, recurrent copy number variants in 1p36.13, 3q29, 8p23.1 and 9p24.3 were significantly enriched in BAV cases. After exclusion of 26 outlier samples in multidimensional scaling analysis, there was no significant genomic inflation (lambda= 1.02). The strongest genome-wide association signals were observed in 1p36.23, 3q23, 12q21.2, 18q21 and 22q13.31, and did not overlap with previously reported loci for BAV. A total of 13 SNPs in 18q21 were positively associated with BAV (OR=2.5-4.3) with a minimum P value of 1x10-7. Replication of these regions in independent groups of cases is ongoing. Conclusion: Our results demonstrate that autosomal variants with large magnitudes of effect contribute to BAV in TS women, confirming our hypothesis, and provide evidence for gene-gene interactions in BAV formation.


Author(s):  
Helen E. Turner ◽  
Richard Eastell ◽  
Ashley Grossman

This chapter discusses the principles of endocrinology, starting with a description of the anatomy of endocrine glands, hormone structures, and hormone receptors. It similarly provides information on hormone measurements, such as immunoassays, mass spectrometry, hormonal-binding proteins, and biological matrices from serum, urine, and saliva. It relates autoimmunity to the endocrine system, and provides examples of studies of genetic endocrine disorders, such as linkage studies, complex endocrine disease-related case control studies, and genome-wide association studies. Providing information on the endocrine epidemiology, this chapter describes ethnic and geographic variation in disorders such as iodine deficiency, thyroid cancer, vitamin D deficiency, pituitary disease, diabetes, and multiple endocrine neoplasia.


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