Autosomal and X chromosome structural variants are associated with congenital heart defects in Turner syndrome: The NHLBI GenTAC registry.

Turner Syndrome (TS) is a developmental disorder caused by partial or complete loss of one sex chromosome. Bicuspid aortic valve and other left-sided congenital heart lesions (LSL), including thoracic aortic aneurysms and acute aortic dissections, are 30-50 times more frequent in TS than in the general population. In 454 TS subjects, we found that LSL are significantly associated with reduced dosage of Xp genes and increased dosage of Xq genes.

X chromosome parental origin and aortic stiffness in turner syndrome.

Introduction: Aortic abnormalities contribute to increased morbidity and mortality of women with Turner syndrome (TS). Impaired aortic stiffness may prove to have clinical prognostic value in TS as is the case in other diseases such as Marfan syndrome, diabetes and hypertension. Additionally, the parental origin of the X chromosome in TS may influence aortic stiffness.

Spectrum of aortic valve abnormalities associated with aortic dilation across age groups in Turner syndrome.

Background: Congenital aortic valve fusion is associated with aortic dilation, aneurysm, and rupture in girls and women with Turner syndrome. Our objective was to characterize aortic valve structure in subjects with Turner syndrome and to determine the prevalence of aortic dilation and valve dysfunction associated with different types of aortic valves.

Methods And Results: The aortic valve and thoracic aorta were characterized by cardiovascular MRI in 208 subjects with Turner syndrome in an institutional review board-approved natural history study.

Single-nucleotide polymorphism array genotyping is equivalent to metaphase cytogenetics for diagnosis of Turner syndrome.

Purpose: Turner syndrome is a developmental disorder caused by partial or complete monosomy for the X chromosome in 1 in 2,500 females. We hypothesized that single-nucleotide polymorphism (SNP) array genotyping could provide superior resolution in comparison to metaphase karyotype analysis to facilitate genotype-phenotype correlations.

Methods: We genotyped 187 Turner syndrome patients with 733,000 SNP marker arrays.

High levels of education and employment among women with Turner syndrome.

Background: Turner Syndrome (TS) is due to X chromosome monosomy and affects ~1 per 2500 females at birth. The major features are short stature and primary ovarian failure. Short stature and monosomy for a maternal X chromosome have been implicated in impaired functionality in adult life; however, data on adult outcomes in TS are limited.

Multilocus loss of DNA methylation in individuals with mutations in the histone H3 lysine 4 demethylase KDM5C.

Background: A number of neurodevelopmental syndromes are caused by mutations in genes encoding proteins that normally function in epigenetic regulation. Identification of epigenetic alterations occurring in these disorders could shed light on molecular pathways relevant to neurodevelopment.

Results: Using a genome-wide approach, we identified genes with significant loss of DNA methylation in blood of males with intellectual disability and mutations in the X-linked KDM5C gene, encoding a histone H3 lysine 4 demethylase, in comparison to age/sex matched controls.

Perturbation of the transforming growth factor β system in Turner syndrome.

Objective: To measure components of the circulating transforming growth factor β (TGFβ) system in patients with Turner syndrome (TS) compared to relevant controls and to ascertain correlation with endocrine and cardiovascular parameters.

Methods: TGFβ1, TGFβ2 and endoglin (a vascular TGF receptor component) were measured using enzyme-linked immunoassays in the sera of 40 subjects with TS and 40 healthy volunteer women. The cardiovascular phenotype in TS subjects was extensively characterized by cardiac magnetic resonance (MR) and echo.

N-terminal pro-brain natriuretic peptide levels and aortic diameters.

Background: Women with X-chromosome monosomy or Turner syndrome (TS) are at increased risk for aortic dilation and dissection. To better understand the pathology and develop tools to monitor the risk of aortic disease, we investigated N-terminal pro-brain natriuretic peptide (BNP) (NT-proBNP) levels in women with TS and healthy female controls.

Methods: We evaluated NT-proBNP levels in women with karyotype-proven TS and healthy female volunteers in relation to ascending aortic diameter and descending aortic diameter measured by cardiovascular magnetic resonance imaging.

Genomic imprinting and Turner syndrome.

The term 'genomic imprinting' refers to selective repression of transcription from distinct chromosomal regions determined by their maternal or paternal inheritance. There are two potentially important aspects of imprinting that may manifest in individuals with X monosomy, or Turner syndrome (TS). Given that men are monosomic for Xm while women are mosaic for Xm:Xp, genomic imprinting of important X-linked genes should be associated with sexually dimorphic traits, e.

Serious aortic complications in a patient with Turner syndrome.

An asymptomatic young woman was discovered to have life-threatening aneurysms and dissection of the thoracic aorta during routine evaluation in a Turner syndrome (TS) study. The presence of a heart murmur and hypertension had led to diagnosis and surgical repair of an atrial septal defect at age 5 and of aortic coarctation at age 12. The diagnosis of TS was made at 16 years of age due to short stature and delayed pubertal development.

Autoimmune disorders in women with turner syndrome and women with karyotypically normal primary ovarian insufficiency.

The higher prevalence of autoimmune diseases in women compared to men could be due to effects of ovarian hormones, pregnancy and/or the presence of a second X chromosome. To elucidate the role of these factors, we investigated the prevalence and spectrum of autoimmune diagnoses in women with primary ovarian insufficiency associated with X chromosome monosomy (Turner syndrome, TS, n = 244) and women with karyotypically normal (46,XX) primary ovarian insufficiency (POI, n = 457) in a prospective study, conducted at the National Institutes of Health. We compared the study group prevalence to normative data for the U.

Outcomes of spontaneous and assisted pregnancies in Turner syndrome: the U.S. National Institutes of Health experience.

Objective: To assess fetal and maternal outcomes of pregnancies in women with Turner syndrome (TS).

Design: Retrospective case series.

Setting: Clinical research center.

Aneurysmal dilatation of medium caliber arteries in Turner syndrome.

Turner syndrome is the most common chromosomal abnormality in female subjects, affecting 1 in 2000 live births. The condition is associated with a generalized vasculopathy as well as congenital cardiac and other defects. We report aneurysmal dilation of medium caliber arteries involving the celiac axis and coronary vessels in two women with Turner syndrome.

Monosomy for the X chromosome.

Dosage compensation serves to equalize X chromosome gene expression in mammalian males and females and involves extensive silencing of the 2nd X chromosome in females. If dosage compensation mechanisms completely suppressed the 2nd X chromosome, then actual physical loss of this "eXtra" chromosome should have few consequences. However, X monosomy has major effects upon normal development, fertility and longevity in humans and some other species.

X-chromosome gene dosage and the risk of diabetes in Turner syndrome.

Background: Turner syndrome (TS) is caused by the absence or fragmentation of the second sex chromosome. An increased risk of diabetes mellitus (DM) has consistently been noted, but the specific phenotype and genetic etiology of this trait are unknown.

Methods: In a prospective study, we examined the prevalence of DM in adult participants in an intramural National Institutes of Health (NIH) TS study.

Turner syndrome 2008.

Background: Fetuses with prenatal diagnoses of 45,X Turner syndrome (TS) and abnormal fetal ultrasounds have poor prognoses for survival, but with modern medical management, those that do survive to birth may have good clinical outcomes. Fetuses with incidental diagnoses of mosaicism for 45,X associated with normal ultrasounds have a high survival rate and may have no or only mild features of TS.

Current Guidelines: At present, appropriate treatment for girls with TS may include growth-promoting therapy and pubertal induction with the dual aims of optimizing adult height and facilitating psychosocial adjustment.

Facilitative glucose transporters in articular chondrocytes. Expression, distribution and functional regulation of GLUT isoforms by hypoxia, hypoxia mimetics, growth factors and pro-inflammatory cytokines.

Articular cartilage is a unique and highly specialized avascular connective tissue in which the availability of oxygen and glucose is significantly lower than synovial fluid and plasma. Glucose is an essential source of energy during embryonic growth and fetal development and is vital for mesenchymal cell differentiation, chondrogenesis, and skeletal morphogenesis. Glucose is an important metabolic fuel for differentiated chondrocytes during postnatal development and in adult articular cartilage and is a common structural precursor for the synthesis of extracellular matrix glycosaminoglycans.

Aortic dissection in Turner syndrome.

Purpose Of Review: Turner syndrome is a relatively common disorder of female development with cardinal features of short stature and congenital cardiovascular defects (CHD). Turner syndrome is the most common established cause of aortic dissection in young women, but has received little attention outside pediatric literature. This review focuses on emerging knowledge of the characteristics of aortic disease in Turner syndrome in comparison with Marfan-like syndromes and isolated aortic valve disease.

Aortic valve disease in Turner syndrome.

Objectives: Our goal was to determine the prevalence and characteristics of aortic valve disease in girls and women with monosomy for the X chromosome, or Turner syndrome (TS).

Background: Complications from congenital aortic valve disease are a major source of premature mortality in TS, but accurate data on the prevalence of aortic valve abnormalities and their association with aortic root dilation are not available.

Methods: This prospective study characterized the aortic valve and proximal aorta in 253 individuals with TS age 7 to 67 years using transthoracic echocardiography as our primary screening tool, supplemented with magnetic resonance imaging.

Fracture risk and bone mineral density in Turner syndrome.

Bone health is a major lifelong concern in caring for women and girls with Turner syndrome (TS). There is an approximately 25% increase in fracture risk most of which is related to medium or high impact trauma. The long bones, especially of the forearm are predominantly affected.

Congenital cardiovascular disease in Turner syndrome.

Turner syndrome (TS), or monosomy X, occurs in approximately 1/2000 live born females. Intelligence is normal and short stature is the most obvious and consistent feature of the syndrome. Congenital cardiovascular disease affects approximately 50% of individuals and is the major cause of premature mortality in adults.