Selective reduction in cortical bone mineral density in turner syndrome independent of ovarian hormone deficiency

Bone mineral density: Comparison between women under hormone replacement therapy with Turner syndrome or idiopathic premature ovarian insufficiency

CONTEXT

Turner syndrome (TS) is characterized by short stature and premature ovarian insufficiency (POI). The main long-term complication of POI is osteoporosis, which can be prevented by hormone replacement therapy (HRT).

OBJECTIVE

The objective of our study was to compare initial bone mineral density (BMD) and progression between TS and idiopathic POI patients under HRT.

METHODS

A single-center retrospective study was conducted between 1998 and 2018. All women had undergone at least two bone densitometry assessments at least 2 years apart.

RESULTS

Sixty-eight TS patients and 67 idiopathic POI patients were included. Mean age at initial assessment was 27 years (IQR, 21-35.5 years) in TS patients and 31.5 years (IQR, 23-37 years) in idiopathic POI patients (P=0.1). Lumbar and femoral neck BMD were lower in the TS group than in the idiopathic POI group (respectively 0.89g/cm2 versus 0.95g/cm2, P=0.03; 0.70g/cm2 versus 0.77g/cm2, P<0.0001). Mosaic karyotype was associated with better BMD in TS patients while history of growth hormone treatment had no impact on BMD. Over time, a significant gain in vertebral BMD was observed in TS patients versus a loss of BMD in idiopathic POI patients (P=0.0009).

CONCLUSION

TS patients had a lower BMD at baseline than idiopathic POI patients, at both spinal and femoral levels. Over time, on HRT, a significant gain in vertebral BMD was observed in patients with TS, compared with a loss of BMD in patients with idiopathic POI. We hypothesized that earlier initiation and longer duration of HRT played an important role in this finding. Long-term prospective follow-up to assess the incidence of fractures in TS would be useful.

Organ Abnormalities Caused by Turner Syndrome

Turner syndrome (TS), a genetic disorder due to incomplete dosage compensation of X-linked genes, affects multiple organ systems, leading to hypogonadotropic hypogonadism, short stature, cardiovascular and vascular abnormalities, liver disease, renal abnormalities, brain abnormalities, and skeletal problems. Patients with TS experience premature ovarian failure with a rapid decline in ovarian function caused by germ cell depletion, and pregnancies carry a high risk of adverse maternal and fetal outcomes. Aortic abnormalities, heart defects, obesity, hypertension, and liver abnormalities, such as steatosis, steatohepatitis, biliary involvement, liver cirrhosis, and nodular regenerative hyperplasia, are commonly observed in patients with TS. The SHOX gene plays a crucial role in short stature and abnormal skeletal phenotype in patients with TS. Abnormal structure formation of the ureter and kidney is also common in patients with TS, and a non-mosaic 45,X karyotype is significantly associated with horseshoe kidneys. TS also affects brain structure and function. In this review, we explore various phenotypic and disease manifestations of TS in different organs, including the reproductive system, cardiovascular system, liver, kidneys, brain, and skeletal system.

Skeletal Characteristics of Children and Adolescents with Turner Syndrome

Turner syndrome (TS) is a chromosomal disorder characterized by a short stature and gonadal dysgenesis, the latter of which requires estrogen replacement therapy (ERT) to induce and maintain secondary sexual characteristics. Insufficient ERT is associated with compromised skeletal health, including bone fragility, in adults with TS. In particular, estrogen insufficiency during adolescence is critical because the acquisition of a defective bone mass during this period results in impaired bone strength later in the life. In addition to bone mass, bone geometry is also a crucial factor influencing bone strength; therefore, a more detailed understanding of the skeletal characteristics of both bone mass and geometry during childhood and adolescence and their relationships with the estrogen status is needed to prevent compromised skeletal health during adulthood in TS. Although a delay in the initiation of ERT is associated with a lower bone mineral density during adulthood, limited information is currently available on the effects of ERT during adolescence on bone geometry. Herein, we summarize the current knowledge on skeletal characteristics in children and adolescents with TS and their relationships with estrogen sufficiency, and discuss the potential limitations of the current protocol for ERT during adolescence in order to achieve better skeletal health in adulthood.

Turner Syndrome: An Update

Turner syndrome is the most common sex chromosome abnormality in women. Infertility and short stature are the most striking findings seen in these patients. Unfortunately, many girls are still being diagnosed too late and therefore early diagnosis and treatment key. Turner syndrome affects many systems of the body; therefore, a comprehensive approach is key for therapeutic intervention.

Role of Wnt-signaling inhibitors DKK-1 and sclerostin in bone fragility associated with Turner syndrome

PURPOSE

Girls affected with Turner syndrome (TS) present with low bone mineral density (BMD) and osteopenia/osteoporosis. Thus, they have an increased risk to develop fractures compared to normal population. The aim of this study was to deepen the pathophysiology of skeletal fragility in TS subjects by evaluating the serum levels of Dickkopf-1 (DKK-1) and sclerostin, main regulators of bone mass, as well as the percentage of circulating osteoblast precursors (OCPs).

METHODS

Thirty-four TS girls and 24 controls were recruited. All subjects underwent anthropometric measures (height, weight, body mass index-BMI). A peripheral venous blood sample was collected to determine serum levels of active intact parathyroid hormone (PTH), 25-OH vitamin D, calcium, phosphorus, bone alkaline phosphatase (bALP), osteocalcin, sclerostin, DKK-1, RANKL and OPG. OCPs were detected by flow cytometry. In TS subjects bone mineralization was measured at lumbar spine by dual energy X-ray absorptiometry (DXA).

RESULTS

bALP, 25-OH Vitamin D, and osteocalcin levels were significant lower in TS subjects than in the controls. Statistically significant higher levels of sclerostin, DKK-1 and RANKL were measured in patients compared with the controls. The percentage of OCPs did not show significant differences between patients and controls. Sclerostin and DKK-1 levels were related with anthropometric parameters, bone metabolism markers, HRT, rhGH therapy, RANKL and lumbar BMAD-Z-score.

CONCLUSION

TS patients showed higher levels of sclerostin and DKK-1 than controls which can be related to HRT, and to reduced bone formation markers as well as the increased bone resorption activity.

The bone densitometry is normal in Turner syndrome prepubertal patients after height age correction

Abstract Objectives: to evaluate the bone mass in prepubertal patients with Turner Syndrome (TS) according to height age (HA) and verify the influence of karyotype and adiposity. Methods: retrospective and analytical study of prepubertal TS patients. The variables analyzed were: karyotype, age at bone densitometry (BD), height, body mass index (BMI) and BD result. The result of the BD was corrected using HA. BMI and BD were calculated on Z score for chronological age (CA) and for HA. Results: thirty-seven prepubertal patients were selected and after exclusion criteria, 13 cases between 10 and 13 years old were included in the study. The BD for HA was significantly higher than for CA (0.39 ± 1.18 x −1.62 ± 1.32), without karyotype (p=0.369) and BMI (p=0.697) influence. Conclusion: prepubertal TS patients present normal BD when corrected for HA, without influence of karyotype and BMI.

A current perspective into young female sex hormone replacement: a review

INTRODUCTION

Hormone replacement in females with hypogonadism is advocated to address the various clinical aspects of estrogen deficiency.

AREAS COVERED

This article focuses on hormone replacement in young females with hypogonadism, including a rationale as to why hormone replacement in such patients differs from treatment in postmenopausal females, a summary of symptoms encountered by females with hypogonadism and a comprehensive discussion of the various treatment options available, specifically focusing on the latest advances in the subject. A Medline search was conducted using different combinations of relevant keywords, giving preference to recent publications.

EXPERT OPINION

Whilst traditionally oral contraceptive pills (containing ethynyl estradiol) were commonly used as a form of hormone replacement, it is now increasingly recognized that this is not the optimal treatment option. Physiological hormone replacement with transdermal estradiol is found to be superior. Evidence suggests that micronized progesterone may be associated with fewer side effects, although its effect on endometrial protection is not yet proven. Synthetic progestins confer varying degrees of androgenic and thromboembolic properties which should be kept in mind when prescribing individualized treatment. Further studies in different sub-cohorts of female patients with hypogonadism might help address the specific needs of individual patients.

Monitoring and maintaining bone health in patients with Turner syndrome

INTRODUCTION

Subjects affected with Turner Syndrome (TS) suffer low bone mineral density and high risk of fracture from a young age. Estrogen deficiency is considered the main risk factor but other factors, such as intrinsic bone abnormalities, enhanced osteoclastogenesis, vitamin D deficiency and other comorbidities may contribute to the exalted bone fragility.

AREAS COVERED

The authors performed a literature search in PubMed and EMBASE, using selected key words. They focused their search on pathogenetic mechanisms of osteoporosis in TS and updated the diagnosis, prevention and therapeutic interventions.

EXPERT OPINION

Bone health is a concern in subjects with TS, and strategies to prevent osteoporosis and fractures should be considered from childhood. Advice on how to live a healthy lifestyle, including physical activity and correct nutrition, should be given during childhood in order to prevent bone impairment later in life. The screening for vitamin D deficiency should be performed between the ages of 9 and 11, and every 2-3 years thereafter. Early initiation of estrogen replacement therapy (ERT) between 11-12 years of age, prompt titration to the adult dose after 2 years, and long-term follow-up to guarantee compliance with ERT, are the key points of osteoporosis prevention in women with TS.

Turner syndrome and osteoporosis

Turner syndrome is one of the most common sex chromosomal anomalies, characterized by the complete or partial loss of one X chromosome. Females with Turner syndrome are characterized by skeletal abnormalities, short stature and primary ovarian insufficiency. The aim of this narrative review was to identify the underlying mechanisms of osteoporosis in Turner syndrome, summarize its clinical manifestations and provide suggestions regarding the management of osteoporosis. Girls and women with Turner syndrome have lower bone mineral density and a higher fracture rate than healthy individuals. The most important risk factors for osteoporosis are inadequately treated primary ovarian insufficiency, followed by intrinsic bone abnormalities. Comorbidities that further increase the risk of osteoporosis include vitamin D deficiency, celiac disease and inflammatory bowel disease. In addition, hearing problems can predispose to falls. Early initiation of hormone replacement therapy (HRT) at the age of 11-13 years, prompt titration to the adult dose after 2 years and long-term follow-up to ensure compliance with HRT are the cornerstones of osteoporosis prevention in women with Turner syndrome.

Prevalence of diverse complications and its association with karyotypes in Japanese adult women with Turner syndrome-a questionnaire survey by the Foundation for Growth Science

The reported prevalence of complications in Turner Syndrome (TS) was highly variable because of the rarity and the limited numbers analyzed. Again, possible presence of other complications that are not described as specific for TS, is also speculated. To resolve these issues, a questionnaire survey was conducted in hGH treated 492 patients with adult TS (17-42 years). The possible association with these complications and karyotypes were also analyzed. The complications and their prevalence were as follows: chronic thyroiditis (25.2%), inflammatory bowel disease (1.8%), congenital cardiovascular anomaly (11.8%), urinary tract malformation (11.8%), low bone mineral density (BMD) (42.9%), scoliosis (8.4%), hearing loss (6.2%), epilepsy (2.8%) and schizophrenia (0.9%). The majority of prevalence of these diseases in TS was higher than in the general population. In distribution, the most frequent karyotype was 45,X monosomy (28.9%), followed by 45,X/46,X,Xi (16.9%), 46,X,Xi (9.1%), and 45,X/46,XX (6.3%), while other mosaic 45,X was noted in 29.9%. Regarding the karyotype, cardiovascular anomaly was more frequent in the 45,X group and less in the 46,X,Xi group. Urinary tract malformation and epilepsy were frequently associated with the chromosome 45,X. The prevalence of low BMD was noticed more in the chromosome 46,X,Xi and 45,X/46,X,Xi, and less in other mosaic 45,X. In conclusion, the more exact prevalence of diverse complications was clarified and it exceeded the prevalence of the majority of complications in general population. As novel findings, it was observed that the prevalence of epilepsy was significantly high, and epilepsy and low BMD were frequently associated with the specific karyotypes.

Causes of low peak bone mass in women

Peak bone mass is the maximum bone mass that accrues during growth and development. Consolidation of peak bone mass normally occurs during early adulthood. Low peak bone mass results from failure to achieve peak bone mass genetic potential, primarily due to bone loss caused by a variety of conditions or processes occurring at younger ages than usual. Recognized causes of low peak bone mass include genetic causes, endocrine disorders, nutritional disorders, chronic diseases of childhood or adolescence, medications, and idiopathic factors.

Dosage of estradiol, bone and body composition in Turner syndrome: a 5-year randomized controlled clinical trial

OBJECTIVE

Reduced bone mineral density (BMD) is seen in Turner syndrome (TS) with an increased risk of fractures, and body composition is characterized by increased body fat and decreased lean body mass. To evaluate the effect of two different doses of oral 17B-estradiol in young TS women on bone mineral density (BMD), biochemical markers of bone turnover and body composition with the hypothesis of a positive effect of the higher dose.

DESIGN

A double-blind 5-year randomized controlled clinical trial. 20 young TS women participated. Inclusion criteria were diagnosis of TS, age 15-25 years and current treatment with 2 mg oral estradiol daily.

METHODS

The low-dose (LD) group was administered 2 mg 17B-estradiol/day orally and placebo, the high-dose (HD) group was administered 2 + 2 mg 17B-estradiol/day orally. Main outcome measures were whole body and regional bone mineral density (BMD), lean body mass (LBM), fat mass (FM) measured yearly by DXA scan and resorptive and formative bone markers in serum.

RESULTS

BMD, whole body and regional, increased over time with an attenuation toward the end of the study, and bone turnover markers decreased over time, both with no differences between the treatment groups (P = 0.2-0.9). LBM increased significantly more in the HD group (P = 0.02). FM remained stable in both groups.

CONCLUSIONS

A steady increase in BMD over time in TS was found similar to healthy young women. The higher estrogen dose did not differentially affect BMD or bone markers. The positive effect on body composition may have long-ranging health benefits in TS.

Poor Compliance to Hormone Therapy and Decreased Bone Mineral Density in Women with Premature Ovarian Insufficiency

Premature ovarian insufficiency leads to through infertility and estrogen deficiency. Optimal management encompasses estrogen replacement therapy. Long-term outcome of women with POI is not known. We design a study to evaluate the medical care, hormone replacement therapy compliance and bone mineral density (BMD) in POI women with at least a five-year follow-up after the first evaluation. One hundred and sixty-two patients (37.3±8.0 years) were evaluated (follow-up 7.9±2.8 years). Sixty-nine patients (42.6%) had stopped their hormone replacement therapy (HRT) for at least one year during the follow up period. BMD determination at initial evaluation and at follow-up visit was completed in 92 patients. At first evaluation, 28 patients (30%) had osteopenia and 7 (8%) had osteoporosis. At follow up, 31 women (34%) had BMD impairment with osteopenia in 61% and osteoporosis in 5%. In univariate analysis and multivariate analysis, there was a significant loss of femoral BMD in women who had stopped their HRT for over a year. In conclusion, this first study concerning long-term follow-up of POI patients shows the poor compliance to their HRT, despite its importance in the prevention of bone demineralization. This study reinforces the need for follow up and specific care for POI women.

A Track Record on SHOX: From Basic Research to Complex Models and Therapy

SHOX deficiency is the most frequent genetic growth disorder associated with isolated and syndromic forms of short stature. Caused by mutations in the homeobox gene SHOX, its varied clinical manifestations include isolated short stature, Léri-Weill dyschondrosteosis, and Langer mesomelic dysplasia. In addition, SHOX deficiency contributes to the skeletal features in Turner syndrome. Causative SHOX mutations have allowed downstream pathology to be linked to defined molecular lesions. Expression levels of SHOX are tightly regulated, and almost half of the pathogenic mutations have affected enhancers. Clinical severity of SHOX deficiency varies between genders and ranges from normal stature to profound mesomelic skeletal dysplasia. Treatment options for children with SHOX deficiency are available. Two decades of research support the concept of SHOX as a transcription factor that integrates diverse aspects of bone development, growth plate biology, and apoptosis. Due to its absence in mouse, the animal models of choice have become chicken and zebrafish. These models, therefore, together with micromass cultures and primary cell lines, have been used to address SHOX function. Pathway and network analyses have identified interactors, target genes, and regulators. Here, we summarize recent data and give insight into the critical molecular and cellular functions of SHOX in the etiopathogenesis of short stature and limb development.

Impact of Growth Hormone on Adult Bone Quality in Turner Syndrome: A HR-pQCT Study

Women with Turner syndrome (TS) are known to be at risk of osteoporosis. While childhood growth hormone (GH) treatment is common in TS, the impact of this therapy on bone health has been poorly understood. The objective of this study was to determine the influence of childhood GH treatment on adult bone quality in women with TS. 28 women aged 17-45 with confirmed TS (12 GH-treated) agreed to participate in this cross-sectional study. Dual X-ray absorptiometry (DXA) of lumbar spine, hip, and radius and high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the radius and tibia were used to determine standard morphological and micro-architectural parameters of bone health. Finite element (FE) analysis and polar moment of inertia (pMOI) were used to estimate bone strength. GH-treated subjects were +7.4 cm taller (95% CI 2.5-12.3 cm, p = 0.005). DXA-determined areal BMD of hip, spine, and radius was similar between treatment groups. Both tibial and radial total bone areas were greater among GH-treated subjects (+20.4 and +21.2% respectively, p < 0.05), while other micro-architectural results were not different between groups. pMOI was significantly greater among GH-treated subjects (radius +35.0%, tibia +34.0%, p < 0.05). Childhood GH treatment compared to no treatment in TS was associated with an increased height, larger bones, and greater pMOI, while no significant difference in DXA-derived BMD, HR-pQCT micro-architectural parameters, or FE-estimated bone strength was detected. The higher pMOI and greater bone size may confer benefit for fracture reduction in these GH-treated patients.

Mechanisms of enhanced osteoclastogenesis in girls and young women with Turner's Syndrome

Subjects with hypergonadotropic hypogonadism due to Turner's syndrome show low cortical mineral density, osteoporosis and risk of fractures. It is not clear if this bone fragility derives from chromosomal abnormalities or is the result of inadequate bone formation due to estrogen deficiency. The aim of this study was to investigate the cellular mechanisms underlying bone fragility in subjects with Turner's syndrome before induction of puberty and after hormonal replacement therapy (HRT). For this purpose, we have evaluated the osteoclastogenic potential of non-fractioned and T-cell depleted cultures of peripheral blood mononuclear cells (PBMCs) belonging to girls with Turner's syndrome who had not been treated with HRT yet, girls and young women who were on HRT and age-matched controls. Untreated subjects showed high FSH serum levels, whereas the other subjects displayed normal FSH serum levels. T-cell immunophenotype was analyzed through flow cytometry. Biochemical and DXA analyses were performed. Spontaneous osteoclastogenesis in non-fractioned and T-cell depleted cultures of PBMC belonging to girls with high FSH levels was more evident than in cultures of subjects with normal FSH levels. In the former, osteoclastogenesis was sustained by monocytes expressing high levels of c-fms, TNF-α and RANK, and T-cells producing high RANKL and TNF-α; in the latter it was supported by T-cells expressing high RANKL levels. CD4(+)CD25(high) T-cells were reduced in all subjects, whereas CD3(+)/CD16(+)/CD56(+) NKT-cells were increased in those with high FSH levels. High RANKL and CTX levels were detected in the sera. Bone impairment was already detectable by DXA in subjects aged under 10, although it became more evident with aging. In conclusion, our results demonstrated that bone fragility in subjects with Turner's syndrome is associated to enhanced osteoclastogenesis. This process seems to be due to high FSH serum levels before HRT, whereas it is caused by high RANKL during HRT.

Safety and efficacy of oxandrolone in growth hormone-treated girls with Turner syndrome: evidence from recent studies and recommendations for use

There has been no consensus regarding the efficacy and safety of oxandrolone (Ox) in addition to growth hormone (GH) in girls with Turner syndrome (TS), the optimal age of starting this treatment, or the optimal dose. This collaborative venture between Dutch, UK and US centers is intended to give a summary of the data from three recently published randomized, placebo-controlled, double-blind studies on the effects of Ox. The published papers from these studies were reviewed within the group of authors to reach consensus about the recommendations. The addition of Ox to GH treatment leads to an increase in adult height, on average 2.3–4.6 cm. If Ox dosages<0.06 mg/kg/day are used, side effects are modest. The most relevant safety concerns are virilization(including clitoromegaly and voice deepening) and a transient delay of breast development. We advise monitoring signs of virilization breast development and possibly blood lipids during Ox treatment, in addition to regular follow-up assessments for TS. In girls with TS who are severely short for age, in whom very short adult stature is anticipated,or in whom the growth rate is modest despite good compliance with GH, adjunctive treatment with Ox at a dosage of 0.03–0.05 mg/kg/day starting from the age of 8–10 years onward scan be considered.

Current concepts surrounding bone health and osteoporosis in Turner syndrome

Although Turner syndrome is the most common chromosomal disorder in women, a great deal remains to be understood in terms of optimal patient care, particularly as it relates to bone health. These women are known to be at risk for osteoporosis and fracture later in life as a result of a multitude of risk factors. While estrogen replacement and childhood growth hormone treatment are now considered standard of care, little is known of the role of further interventions to prevent and treat osteoporosis in these women. This review aims to highlight the specifics of bone health in Turner syndrome. We explore the bone diagnostic modalities and therapeutic interventions available and their role in the coming years of bone health management in this unique population.

Bone mineral density in Turner's syndrome and the influence of pubertal development

AIM

To describe bone mineral density at the lumbar spine in a group of girls with Turner's syndrome and determine its relation to pubertal development.

METHODS

Girls with Turner's syndrome aged over 12 years were invited to participate in the study. All participants underwent auxology, pubertal assessment and laboratory evaluation. Bone mineral density was estimated by dual-energy X-ray absorptiometry. Bone mineral apparent density was then calculated, and the results were compared with age-matched Dutch reference data.

RESULTS

We studied 32 girls with Turner's syndrome, mean (SD) [range] age 16.7 (2.6) [12.4-20.2] years and height 148.3 (9.0) [126-159.2] cm. Bone mineral apparent density lumbar spine values were -0.87 SD, significantly lower than in the reference population (p <0.001). Bone mineral apparent density values were positively and significantly associated with breast Tanner stages and postmenarcheal status, but not spontaneous puberty. However, no significant association was found between bone mineral apparent density and karyotype, growth hormone or timing of oestrogen therapy.

CONCLUSION

Girls with Turner's syndrome have lower bone mineral apparent density values at the lumbar spine, even after correcting for size, compared with an age- and sex-matched general population. Pubertal development has significant impact on bone mineral apparent density in girls with Turner's syndrome.

Turner syndrome with primary hyperparathyroidism

Turner syndrome has multiple comorbidities such as osteoporosis, obesity, diabetes, hypothyroidism, and hypertension. As they are treatable conditions in Turner syndrome, early recognition and proper treatment should be needed. We report on a 23-year-old woman with Turner syndrome who presented with severe osteoporosis and hypercalcemia. Laboratory tests showed elevated levels of serum calcium and parathyroid hormone. Dual-energy X-ray absorptiometry showed severe osteopo-rosis (z score, -3.5). Ultrasound and (99m)Tc scintigraphy of parathyroid glands showed an adenoma in the right inferior gland. She was diagnosed with primary hyperparathyroidism due to an adenoma of the parathyroid gland. After excision of the adenoma, the patient's serum calcium and parathyroid hormone levels returned to normal. Although only a few cases of Turners syndrome with primary hyperparathyroidism have been reported, hyperparathyroidism should be considered in cases of Turner syndrome with severe osteoporosis and hypercalcemia.

Endocrine diseases, perspectives and care in Turner syndrome

Turner syndrome is a frequent chromosome disorder in clinical practice. It is characterized by short stature, gonadal dysgenesia and multisystemic involvement, responsible for a high morbidity and reduced life expectancy. The aim of the present paper is to describe the endocrinopathies and major problems at different ages, and to present suggestion for follow-up care in these patients.

Compromised trabecular microarchitecture and lower finite element estimates of radius and tibia bone strength in adults with turner syndrome: a cross-sectional study using high-resolution-pQCT

Although bone mass appear ample for bone size in Turner syndrome (TS), epidemiological studies have reported an increased risk of fracture in TS. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to measure standard morphological parameters of bone geometry and microarchitecture, as well as estimated bone strength by finite element analysis (FEA) to assess bone characteristics beyond bone mineral density (BMD) that possibly contribute to the increased risk of fracture. Thirty-two TS patients (median age 35, range 20-61 years) and 32 healthy control subjects (median age 36, range 19-58 years) matched with the TS participants with respect to age and body-mass index were studied. A full region of interest (ROI) image analysis and a height-matched ROI analysis adjusting for differences in body height between groups were performed. Mean bone cross-sectional area was lower in TS patients in radius (-15%) and tibia (-13%) (both p < 0.01) whereas cortical thickness was higher in TS patients in radius (18%, p < 0.01) but not in tibia compared to controls. Cortical porosity was lower in TS patients at both sites (-32% in radius, -36% in tibia, both p < 0.0001). Trabecular integrity was compromised in TS patients with lower bone volume per tissue volume (BV/TV) (-27% in radius, -22% in tibia, both p < 0.0001), trabecular number (-27% in radius, -12% in tibia, both p < 0.05), and higher trabecular spacing (54% in radius, 23% in tibia, both p < 0.01). In the height-matched ROI analysis, differences remained significant apart from total area at both sites, cortical thickness in radius, and trabecular number in tibia. FEA estimated failure load was lower in TS patients in both radius (-11%) and tibia (-16%) (both p < 0.01) and remained significantly lower in the height-matched ROI analysis. Conclusively, TS patients had compromised trabecular microarchitecture and lower bone strength at both skeletal sites, which may partly account for the increased risk of fracture observed in these patients.

Turner's syndrome presenting as metabolic bone disease

Turner's syndrome is a genetic disorder with a complete or partial absence of one X chromosome with characteristic phenotypic features. The prevalence of renal anomalies in turner syndrome is 30-40%. However, the renal function is usually normal. We report a case of Turner's syndrome presenting with chronic kidney disease and renal osteodystrophy.

Clinical review: Turner syndrome: updating the paradigm of clinical care

CONTEXT

Turner syndrome (TS), in which there is loss of all or part of one sex chromosome, occurs in one in 2500 live-born females and is associated with characteristic findings. Detailed healthcare checklists and screening guidelines are commonly used to detect known complications affecting individuals with TS. Even with the use of these guidelines, there remains an increased morbidity and mortality seen in TS as compared to the general population, leading to significant controversy on optimal management of several aspects of TS.

EVIDENCE ACQUISITION AND SYNTHESIS

A PubMed search of articles from the past 15 yr identified available studies related to the diagnosis and management of common issues related to TS as well as important historical articles. This review summarizes studies through January 2012 and highlights recent developments.

CONCLUSIONS

There remain many areas of uncertainty in the diagnosis and management of TS. Generalizations from experience in the care of other conditions in isolation (such as poor growth, follow-up of cardiac disease, or the treatment of ovarian failure) cannot be broadly applied when caring for individuals with TS. Specific differences include treatment of growth failure as early as possible; acquisition of adequate baseline cardiac studies, followed by serial magnetic resonance imaging, targeted to identify findings unique to TS that address the increased risk of aortic dissection; initiation of hormone replacement at the normal age of puberty, preferentially with transdermal estradiol; and detailed patient counseling to explain the long-term health risks commonly associated with this disorder. A revised paradigm of care using a standardized multidisciplinary evaluation, supplementing screening tests as advocated by expert opinion guidelines, can aid clinicians in interpreting the results of diagnostic testing in the context of TS. This approach optimizes medical care for women with TS and may reduce the increased morbidity and mortality currently seen in this population.

Sex hormone replacement in Turner syndrome

The cardinal features of Turner syndrome (TS) are short stature, congenital abnormalities, infertility due to gonadal dysgenesis, with sex hormone insufficiency ensuing from premature ovarian failure, which is involved in lack of proper development of secondary sex characteristics and the frequent osteoporosis seen in Turner syndrome. But sex hormone insufficiency is also involved in the increased cardiovascular risk, state of physical fitness, insulin resistance, body composition, and may play a role in the increased incidence of autoimmunity. Severe morbidity and mortality affects females with Turner syndrome. Recent research emphasizes the need for proper sex hormone replacement therapy (HRT) during the entire lifespan of females with TS and new hypotheses concerning estrogen receptors, genetics and the timing of HRT offers valuable new information. In this review, we will discuss the effects of estrogen and androgen insufficiency as well as the effects of sex HRT on morbidity and mortality with special emphasis on evidence based research and areas needing further studies.

Effects of hypogonadism on bone metabolism in female adolescents and young adults

Gonadal steroids, including androgens and oestrogens, play a critical part in bone metabolism, and conditions associated with a deficiency of gonadal steroids can reduce BMD in adults and impair bone accrual in adolescents. In addition, other associated hormone alterations, for example, insulin-like growth factor 1 deficiency or high cortisol levels, can further exacerbate the effect of hypogonadism on bone metabolism, as can factors such as calcium and vitamin D deficiency, low body weight and exercise status. This Review discusses the effects of different hypogonadal states on bone metabolism in female adolescents and young adults, with particular emphasis on conditions associated with low energy availability, such as anorexia nervosa and athletic amenorrhoea, in which many factors other than hypogonadism affect bone. In contrast to most hypogonadal conditions, in which replacement of gonadal steroids is sufficient to normalize bone accrual rates and BMD, gonadal steroid replacement may not be sufficient to normalize bone metabolism in these states of energy deficit.

Bone geometry and volumetric bone mineral density in girls with Turner syndrome of different pubertal stages

OBJECTIVE

An increased rate of fractures has been reported in patients with Turner syndrome (TS). We aimed to assess bone geometry and volumetric bone mineral density (vBMD) at the radius in girls with TS and to evaluate the relationships between bone parameters and fracture history.

METHODS AND DESIGN

Sixty-seven girls with TS aged 6-19 years treated currently or in the past with growth hormone (GH) and/or oestrogens were examined using peripheral quantitative computed tomography. Results were compared to reference data.

RESULTS

Cortical area and cortical thickness were low in all age groups (all P<0·001). Height-adjusted total bone area at the diaphysis was increased in prepubertal and postpubertal girls (mean Z-score 1·0, P<0·05 for both) and normal in the pubertal group (mean Z-score 0·1). Cortical vBMD was decreased (mean age-specific Z-scores -2·0, -1·6 and -1·0 for prepubertal, pubertal and postpubertal groups, respectively, P<0·01 for all groups). Height- , age- and cortical thickness-adjusted cortical vBMD was positively correlated to the duration of GH therapy (P=0·012) and to oestrogen administration (P=0·047). Girls with a history of fractures had lower total vBMD at the metaphysis compared to nonfractured TS girls (mean Z-scores -1·7 vs-0·9, P=0·04).

CONCLUSIONS

There is a cortical bone deficit in girls with TS characterized by low cortical area, thin cortex and probably decreased cortical vBMD. Early commencement of GH therapy, as well as oestrogen replacement, is associated with higher cortical vBMD. Further studies should investigate the potential causality of this relation.

Vitamin D receptor genotypes are associated with bone mass in patients with Turner syndrome

BACKGROUND

Turner syndrome (TS) patients present low bone mineral density (BMD) and increased fracture risk, probably due to a genetic defect aggravated by hormonal deficiency.

AIM

To study the relationship between vitamin D receptor (VDR) gene polymorphisms and BMD and bone parameters in TS patients.

METHODS

DNA from 65 TS patients and 110 controls was amplified by PCR and digested with FokI, BsmI and ApaI restrictases. Lumbar and femoral BMD were determined by DEXA and serum intact parathyroid hormone, osteocalcin and beta-CrossLaps by electrochemiluminescence.

RESULTS

Genotype distribution within the ApaI site was different in both groups: genotype Aa was more abundant in TS (63.8% vs. 41.3%; p<0.01), whereas AA predominated in controls (33.9% vs. 15.5%; p<0.01). Patients carrying genotype bb (BsmI) or ff (FokI) had lower BMD than those with other genotypes (p<0.01 and p<0.05, respectively).

CONCLUSION

BsmI and FokI polymorphic sites of VDR could be genetic determinants of BMD in TS patients.

Reduced cortical bone density with normal trabecular bone density in girls with Turner syndrome

SUMMARY

This study of 22 girls with Turner syndrome (TS) demonstrates a reduction in bone mineral apparent density (BMAD) at the femoral neck along with a reduction in cortical bone density at the radius (with sparing of trabecular bone). These findings may account for the increased fracture risk noted in this population.

INTRODUCTION

Increased fracture risk is a feature of TS; however, the reasons for this are unclear. Little is known regarding cortical and trabecular bone mineral density (BMD) in TS. We have addressed this by measurement of volumetric bone mineral density (vBMD) using peripheral quantitative computed tomography (pQCT).

METHODS

We studied 22 females with TS and 21 females without TS; mean ages 12.7 and 12.9 years, respectively. Bone mass measurements were made by dual-energy X-ray absorptiometry (DXA) of the lumbar spine and femur and pQCT of the radius. BMAD was calculated from DXA values. We utilized published reference data to generate Z-scores for both populations.

RESULTS

The mean BMAD Z-score at the lumbar spine was not significantly different in individuals with TS compared to the controls. At the femoral neck, individuals with TS had a significantly lower BMAD Z-score compared to the controls (-1.32 vs. -0.14, p = 0.001). At the distal radius, total vBMD Z-score and trabecular vBMD Z-score were not significantly different between the TS group and controls. A significant reduction in cortical vBMD at the proximal radius was noted in the TS group however (-2.58 vs. -1.38, p = 0.02). There was also a trend towards reduced cortical thickness at this site in the TS group (Z-score -2.89 vs. -1.73, p = 0.08).

DISCUSSION

TS is associated with reduced BMAD at the femoral neck; pQCT data suggests that cortical density is reduced with sparing of trabecular bone. This differential of cortical and trabecular BMD may predispose to fracture.

Androgen replacement therapy in Turner syndrome: a pilot study

CONTEXT

Women with Turner syndrome (TS) have reduced levels of androgens due to ovarian failure.

HYPOTHESES

Morbidity associated with TS, such as bone fragility, metabolic changes, obesity, neurocognitive profile, and sexual problems may partly relate to androgen insufficiency and improve on androgen replacement therapy (ART).

OBJECTIVES

The objective of the study was to determine the effect of androgens on morbidity in TS.

DESIGN

Fourteen TS women (aged 17-27 yr) participated in a randomized, double-blind, placebo-controlled crossover pilot. The study was conducted in a hospital outpatient clinic between December 2001 and July 2004.

INTERVENTION

TS patients were on estrogen/progestin replacement therapy. Subjects received oral 1.5 mg methyl testosterone (ART) or placebo for 1 yr and the alternative for another year.

MAIN OUTCOME MEASURES

The study compared body composition as a primary outcome, and physiology, biochemistry, visceral fat, cognition, and quality of life (QOL) as secondary outcomes.

RESULTS

ART as compared with placebo reduced total cholesterol, triglycerides, and high-density lipoprotein cholesterol. It improved bone mineral density, increased lean body mass, and decreased fat mass. ART improved attention, reaction time, and verbal memory and had no effect on executive functions and spatial cognition. Patients reported improved QOL, including general health, coping with stress, and sexual desire.

CONCLUSIONS

Androgen insufficiency plays a role in TS-impaired body composition, neurocognition, and QOL, and these aspects improve with ART, which was safe and effective when given for 1 yr.

Bone mineral density in estrogen-deficient young women

CONTEXT

Osteoporosis primarily affects postmenopausal women. However, young women with estrogen deficiency also are at increased risk for low bone density.

OBJECTIVE

The aim of the study was to assess bone density and associated risk factors for reduced bone density in young, estrogen-deficient women using primary ovarian insufficiency (POI) as the disease model.

DESIGN AND SETTING

We conducted a cross-sectional study at a tertiary care research center.

PARTICIPANTS

We studied women with POI (n = 442), concurrent controls (n = 70), and matched controls from NHANES III (n = 353).

PRIMARY OUTCOME MEASURE

We measured bone mineral density (BMD) using dual-energy x-ray absorptiometry.

RESULTS

Patients on average had 2-3% lower BMD at L1-L4, femoral neck, and total hip (P < 0.01 at all sites). The modifiable risk factors for BMD below the expected range for age (Z-score <-2) were: more than 1-yr delay in diagnosis of estrogen deficiency (P = 0.018), low (<32 ng/ml) vitamin D levels (P = 0.002), estrogen replacement nonadherence (P = 0.002), low calcium intake (P = 0.005), and lack of exercise (P = 0.005). As compared to Caucasians, African-American and Asian women with POI were 3.18 and 4.34 times more likely, respectively, to have Z-scores below -2 (P = < 0.0001 for both). Race was an overall risk factor, but on regression modeling, not an independent predictor of low bone density.

CONCLUSIONS

Women with POI have lower bone density compared to regularly menstruating women. Compared to Caucasians, minority women with estrogen deficiency are more likely to have BMD below the expected range for age. This racial disparity appears to be related to a combined effect of several modifiable risk factors. Delay in diagnosis of POI also contributes to reduced bone density by delaying proper therapy.

Turner syndrome: transition from pediatrics to adulthood

OBJECTIVE

To highlight the importance of an improved, seamless, and effective transition from pediatric to adult care, especially for medically complex conditions such as Turner syndrome (TS).

METHODS

The morbidities in adult patients with TS are reviewed, including features of the metabolic syndrome, congenital and acquired cardiovascular conditions, osteopenia and osteoporosis, autoimmune thyroid disease, and obesity, and psychobehavioral issues are addressed, in terms of promoting the development of independent self-care and autonomy in adolescent patients.

RESULTS

An essential component of high-quality health care, transition for adolescents with TS needs to be reengineered as a staged process initiated during early-stage adolescence (about age 12 years), when exogenous estrogen therapy is begun in coordination with the final phase of growth hormone therapy. At this time, the focus of care shifts from the parent to the adolescent and from maximizing final adult height to inducing puberty with gradually increasing doses of estrogen. During this transition, the development of healthful and independent healthcare behaviors should be promoted to prepare patients with TS for the adult responsibility of self-care. During the final phase of transition, an adult care plan should be formulated in collaboration with the adolescent with TS and her providers of adult care to improve the likelihood that she will continue to be carefully monitored in a way that optimizes her adult health and longevity.

CONCLUSION

The transitional period from pediatrics to adulthood is the ideal time for patients with TS to be made aware of their health history and health needs and of the evolving impact of TS into adulthood.

Dual-energy X-ray aborptiometry assessment in children and adolescents with diseases that may affect the skeleton: the 2007 ISCD Pediatric Official Positions

The Task Force focusing on the use of dual energy X-ray absorptiometry (DXA) in children and adolescents with diseases that may affect the skeleton reviewed over 300 articles to establish the basis for the Official Positions. A significant number of studies used DXA-based outcome measures to assess the effects of specific interventions and charted the natural history of incremental changes in bone size and mass in specific disease states in children. However, the utility of DXA in clinical practice has not been evaluated systematically, in large part due to the lack of a workable definition for childhood osteoporosis. Thus, in combination with the Official Positions addressing the diagnosis of osteoporosis in children, and the reporting of DXA results in children, this document presents clear guidelines from which clinicians and researchers alike can work. This report delineates a set of disorders in which it is appropriate to use DXA as part of the comprehensive assessment of skeletal health in children and adolescents, and provides guidance concerning the initiation of assessment and the frequency of monitoring. Importantly, this document also highlights significant gaps in our knowledge, emphasizing areas for future research.

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. This fact may be due to a selective cortical bone deficiency in TS which is unrelated to hypogonadism. In addition, lack of adequate estrogen replacement can lead to trabecular bone deficiency and increase in vertebral compression fractures after age 45. Evaluation of bone density by dual X-ray absorptiometry (DEXA) is important, however, it should be used judiciously in TS in view of its inherent tendency to underestimate the bone density of people with short stature. Bone size-independent methods, such as QCT or volumetric transformation of DEXA data should be used in individuals shorter than 150 cm. Achieving optimal bone density is of critical importance for fracture prevention in TS, and should be pursued by timely introduction of hormone replacement therapy, adequate dose of estrogens during the young adult life, optimal calcium and vitamin D intake and regular physical exercise. In addition, other measures to prevent fall and trauma should be considered, including optimizing hearing and vision, avoiding contact sports and exercise to improve coordination.

The effect of growth hormone treatment on bone mineral density in prepubertal girls with Turner syndrome: a multicentre prospective clinical trial

BACKGROUND

Patients with Turner syndrome (TS) are treated with GH to increase adult height. Although it is well established that GH promotes longitudinal bone growth, the effects of GH treatment on bone density are less clear.

OBJECTIVE

To determine how GH treatment affects trabecular bone mineral density (BMD) in girls with TS at prepubertal ages in a prospective multicentre study.

PATIENTS AND METHOD

Twenty-two patients with TS in the prepubertal period with a mean age of 9.8 +/- 2.5 (range 3.6-12.8) years were included in the study. All girls with TS underwent measurement of areal BMD using dual-energy X-ray absorptiometry (DXA) to obtain pretreatment anteroposterior (AP) lumbar spine values at L1-L4. Patients received GH (Genotropin) subcutaneously for 1 year at a dose of 0.05 mg/kg/day. Height and weight were measured at 3-monthly intervals. The AP lumbar spine areal BMD was remeasured using the same technique after 1 year of treatment. Lumbar spine BMD Z-scores and volumetric BMD (vBMD) Z-scores were calculated using national standards.

RESULTS

The height SDS of our cases showed a significant increase with GH therapy. The pretreatment lumbar spine (L1-L4) BMD Z-score was -1.2 +/- 1.2 SD and the vBMD Z-score was -0.8 +/- 1.6 SD. There were no significant changes in these values after 1 year of GH treatment. Prepubertal TS girls more than 11 years of age had lower vBMD Z-scores (-1.7 +/- 1.7 SD) than the girls aged less than 11 (-0.1 +/- 1.0 SD) (P < 0.05) at the onset of therapy. No significant changes were observed in these values after 1 year of GH therapy.

CONCLUSIONS

Osteopaenia becomes apparent in prepubertal TS patients as they reach pubertal age. BMD evaluation may be necessary in these prepubertal TS girls at diagnosis. Short-term GH therapy in these TS patients does not have a significant effect on bone density when measured at a site with a predominance of trabecular bone.

A Case of Turner Syndrome with Hyperparathyroidism in an Adult

Turner syndrome is a hereditary chromosomal anomaly that affects girls and women. A result of gonadal dysgenesis, its primary characteristics are short stature, osteoporosis, neck webbing, and cardiac defects. Turner syndrome may also involve the auditory system and kidneys. We report the case of a woman with Turner syndrome who presented late in adulthood with severe osteoporosis and hypercalcemia. She was subsequently diagnosed with primary hyperparathyroidism secondary to a parathyroid adenoma. After excision of the adenoma, the woman's serum calcium level normalized. To the best of our knowledge, only 4 other cases of Turner syndrome with hyperparathyroidism have been reported in the literature.

Normal DXA bone mineral density but frail cortical bone in Turner's syndrome

CONTEXT

Patients with Turner's syndrome have normal bone mineral density by dual energy X-ray absorptiometry (DXA), but a predisposition for fractures. Quantitative ultrasonography (QUS) measures cortical bone strength.

OBJECTIVE

To compare QUS with DXA in patients with Turner's syndrome.

PATIENTS AND METHODS

Twenty-seven Turner's syndrome patients, aged 21.1 +/- 6.3 years (mean +/- SD), were evaluated by DXA, measuring two-dimensional bone mineral density (BMD), and QUS, measuring speed of sound (SOS) of the radius and tibia. The results were compared to sex- and age-matched (Ctr A, n = 53) and height-matched (Ctr B, n = 34) control groups.

RESULTS

Fracture incidence per 1000 women years was 4.76 in Ctr A, 5 in Ctr B and 7.69 in Turner's patients. In Turner's syndrome patients, QUS results were significantly lower than in controls, whereas DXA Z-scores were not different from reference values. Correlation between tibia and radius SOS and height and age in controls (P < 0.0001) was not evident in Turner's syndrome. Oestrogen or growth hormone therapy had no effect on either QUS or DXA parameters.

CONCLUSIONS

Bone fragility in Turner's syndrome is reflected by low SOS but not by DXA BMD. Low QUS, which assesses the cortical bone only, supports a defect in cortical bone in Turner's syndrome. Lack of SOS correlation with age, height and hormonal therapy in Turner's syndrome suggests a primary bone defect, rather than enhanced resorption of endocrine origin.

Turner syndrome: update on current therapies

New treatments for girls and women with Turner syndrome (monosomy X) have dramatically improved their quality of life and health. Young girls are treated with growth hormone to enhance adult height, and with estrogen to induce and maintain feminization, and prevent osteoporosis. Vigilant screening for otitis, thyroid disease, hypertension, dyslipidemia and diabetes allows for early and effective medical treatment of these common problems. Comprehensive cardiovascular evaluation and regular monitoring of aortic diameter are essential to identify individuals at risk for dissection or rupture. Insights derived from the study of metabolic risk factors in women with Turner syndrome may illuminate gender differences in atherosclerotic heart disease.

The effects of growth hormone treatment on bone mineral density and body composition in girls with turner syndrome

BACKGROUND

Many girls with Turner syndrome (TS) are treated with GH to increase adult height. In addition to promoting longitudinal bone growth, GH has effects on bone and body composition.

OBJECTIVE

The objective was to determine how GH treatment affects bone mineral density (BMD) and body composition in girls with TS.

METHOD

In a cross-sectional study, we compared measures of body composition and BMD by dual energy x-ray absorptiometry, and phalangeal cortical thickness by hand radiography in 28 girls with TS who had never received GH and 39 girls who were treated with GH for at least 1 yr. All girls were participants in a National Institutes of Health (NIH) Clinical Research Center (CRC) protocol between 2001 and 2006.

RESULTS

The two groups were similar in age (12.3 yr, sd 2.9), bone age (11.5 yr, sd 2.6), and weight (42.8 kg, sd 16.6); but the GH-treated group was taller (134 vs. 137 cm, P = 0.001). The average duration of GH treatment was 4.2 (sd 3.2) yr (range 1-14 yr). After adjustment for size and bone age, there were no significant differences in BMD at L1-L4, 1/3 radius or cortical bone thickness measured at the second metacarpal. However, lean body mass percent was higher (P < 0.001), whereas body fat percent was lower (P < 0.001) in the GH-treated group. These effects were independent of estrogen exposure and were still apparent in girls that had finished GH treatment at least 1 yr previously.

CONCLUSIONS

Although GH treatment has little effect on cortical or trabecular BMD in girls with TS, it is associated with increased lean body mass and reduced adiposity.

Healthcare for adolescents with Turner syndrome

This review paper highlights important healthcare issues for adolescents with Turner Syndrome. Turner Syndrome potentially affects multiple organ systems including: cardiovascular, renal, endocrine, neurologic, gastrointestinal, skin, skeletal, auditory, and reproductive systems. Congenital and acquired cardiac defects remain the most significant health problem faced by women with Turner Syndrome.

Investigation of cardiac status and bone mineral density in Turner syndrome

This review highlights recent developments in the detection and management of congenital heart disease and osteoporosis in patients with monosomy X, or Turner syndrome (TS). Magnetic resonance angiography (MRA) using gadolinium as a contrast agent demonstrates a higher prevalence and greater diversity of congenital cardiovascular defects than previously recognized in TS. Almost 50% of girls and women with TS have marked tortuosity or ectasia of the aortic arch, suggesting that these individuals may be at greater risk for aneurysm formation or dissection and therefore require closer monitoring. MRA also reveals that major venous anomalies are common in TS, with partial anomalous pulmonary venous return and persistent left superior vena cava each found in about 13% of patients. MR imaging even without contrast is a valuable complement to routine cardiac ultrasound in detecting abnormalities of the aortic valve. Abnormal electrocardiographic findings, including prolongation of the QTc interval, have recently been documented in many individuals with TS. Conduction and repolarization abnormalities have not been associated with congenital anatomic defects and are as common in young girls as adults. The clinical significance of these electrophysiological findings is unknown at present, but attention to the ECG in TS is important, particularly in monitoring the QTc when prescribing drugs associated with QT prolongation. Patients with TS are at high risk for osteoporosis as a result of premature ovarian failure and intrinsic bone abnormalities specific to the syndrome. Low cortical bone mineral density (BMD) is apparent in prepubertal girls, and it remains low in adults, independent of estrogen treatment and other hormonal factors. The low mineralization of cortical bone in TS may be associated with a small increased fracture risk, but no treatments are known to increase cortical bone mineral content in TS. Trabecular BMD is normal in TS women who have received continuous estrogen treatment from their mid-teens, although areal densitometry scores may be misleadingly low in very small patients. However, young women with ovarian failure who have not received estrogen treatment for extended periods of time are at high risk for osteoporosis of trabecular bone of the spine, with associated compression fractures and height loss. Therefore, judicious management of estrogen therapy to prevent osteoporosis while minimizing estrogen-associated adverse events is a challenging aspect of care for girls and women with TS.

New issues in the diagnosis and management of Turner syndrome

This review has tried to update our view of TS, highlighting the less severe phenotype we are seeing today, aiming to motivate clinicians to scrutinize normal looking short girls more closely, and to provide more relevant information for those counseling prospective parents on the implications of a TS karyotype during prenatal screening. New approaches to cardiac evaluation, including imaging with MR and ECG analysis-were suggested to strengthen our ability to detect and prevent potentially life-threatening cardiac complications. The new emphasis on reproductive potential and concerns about the adequacy and safety of current HRT regimens certainly require further studies and adjustment of treatment strategies in light of new priorities and safety concerns. In the same vein, prospective studies are required to assess the outcome and safety of assisted pregnancy in TS, which, despite the warning ofa potential catastrophic increase in maternal morbidity is going to become a much more common occurrence in the near future.