Endocrine autoimmunity in Turner syndrome

Analysis of genetic variability in Turner syndrome linked to long-term clinical features

Background

Women with Turner syndrome (TS) (45,X and related karyotypes) have an increased prevalence of conditions such as diabetes mellitus, obesity, hypothyroidism, autoimmunity, hypertension, and congenital cardiovascular anomalies (CCA). Whilst the risk of developing these co-morbidities may be partly related to haploinsufficiency of key genes on the X chromosome, other mechanisms may be involved. Improving our understanding of underlying processes is important to develop personalized approaches to management.

Objective

We investigated whether: 1) global genetic variability differs in women with TS, which might contribute to co-morbidities; 2) common variants in X genes - on the background of haploinsufficiency - are associated with phenotype (a "two-hit" hypothesis); 3) the previously reported association of autosomal TIMP3 variants with CCA can be replicated.

Methods

Whole exome sequencing was undertaken in leukocyte DNA from 134 adult women with TS and compared to 46,XX controls (n=23), 46,XX women with primary ovarian insufficiency (n=101), and 46,XY controls (n=11). 1) Variability in autosomal and X chromosome genes was analyzed for all individuals; 2) the relation between common X chromosome variants and the long-term phenotypes listed above was investigated in a subgroup of women with monosomy X; 3) TIMP3 variance was investigated in relation to CCA.

Results

Standard filtering identified 6,457,085 autosomal variants and 126,335 X chromosome variants for the entire cohort, whereas a somatic variant pipeline identified 16,223 autosomal and 477 X chromosome changes. 1) Overall exome variability of autosomal genes was similar in women with TS and control/comparison groups, whereas X chromosome variants were proportionate to the complement of X chromosome material; 2) when adjusted for multiple comparisons, no X chromosome gene/variants were strongly enriched in monosomy X women with key phenotypes compared to monosomy X women without these conditions, although several variants of interest emerged; 3) an association between TIMP3 22:32857305:C-T and CCA was found (CCA 13.6%; non-CCA 3.4%, p<0.02).

Conclusions

Women with TS do not have an excess of genetic variability in exome analysis. No obvious X-chromosome variants driving phenotype were found, but several possible genes/variants of interest emerged. A reported association between autosomal TIMP3 variance and congenital cardiac anomalies was replicated.

Thyroid autoimmunity and autoimmune thyroid disease in Malaysian girls with Turner syndrome: An understudied population

AIMS

Knowledge on the spectrum of thyroid disorders amongst Turner syndrome (TS) patients in Southeast Asia is limited. This study aimed to evaluate the prevalence of thyroid autoimmunity, the spectrum of autoimmune thyroid disease and association with age and karyotype amongst Malaysian TS girls.

METHODS

A cross-sectional study was conducted at 11 paediatric endocrine units in Malaysia. Blood samples for antithyroglobulin antibodies, antithyroid peroxidase antibodies and thyroid function test were obtained. In patients with pre-existing thyroid disease, information on clinical and biochemical thyroid status was obtained from medical records.

RESULTS

Ninety-seven TS patients with a mean age of 13.4 ± 4.8 years were recruited. Thyroid autoimmunity was found in 43.8% of TS patients. Nineteen per cent of those with thyroid autoimmunity had autoimmune thyroid disease (Hashimoto thyroiditis in 7.3% and hyperthyroidism in 1% of total population). Patients with isochromosome X and patients with 45,X mosaicism or other X chromosomal abnormalities were more prone to have thyroid autoimmunity compared to those with 45,X karyotype (OR 5.09, 95% CI 1.54-16.88, P = 0.008 and OR 3.41, 95% CI 1.32-8.82, P = 0.01 respectively). The prevalence of thyroid autoimmunity increased with age (33.3% for age 0-9.9 years; 46.8% for age 10-19.9 years and 57.1% age for 20-29.9 years) with autoimmune thyroid disease detected in 14.3% during adulthood.

CONCLUSION

Thyroid autoimmunity was significantly associated with the non 45,X karyotype group, particularly isochromosome X. Annual screening of thyroid function should be carried out upon diagnosis of TS until adulthood with more frequent monitoring recommended in the presence of thyroid autoimmunity.

Novel insights in Turner syndrome

PURPOSE OF REVIEW

Turner syndrome is the most common sex chromosome abnormality in female individuals, affecting 1/2000-1/2500 female newborns. Despite the high incidence of this condition, the mechanisms underlying the development of multiorgan dysfunction have not been elucidated.

RECENT FINDINGS

Clinical features involve multiple organ systems and include short stature, dysmorphic facial features, delayed puberty and gonadal failure, cardiac and renal abnormalities, audiologic abnormalities, and a high prevalence of endocrine and autoimmune disorders. Paucity of available genotype/phenotype correlation limits the ability of clinicians to provide accurate guidance and management. Given the advent of robust genetic testing and analysis platforms, developments in the genetic basis of disease are materializing at a rapid pace.

SUMMARY

The objective of this review is to highlight the recent advances in knowledge and to provide a framework with which to apply new data to the foundational understanding of the condition.

[Thyrotoxicosis in a patient with Turner syndrome: radioactive iodine therapy]

Turner syndrome (TS) is a chromosomal disorder affecting female and characterized by complete or partial monosomy of the X chromosome. These genetic changes lead to the abnormalities in growth and development and increase the risk of autoimmune diseases, including those affecting the thyroid. Thyroid pathology in TS may include autoimmune thyroiditis, hypothyroidism, thyrotoxicosis (Graves disease, AIT in the hyperthyroid state).Thyrotoxicosis is the clinical syndrome of excess circulating thyroid hormones. One of the main causes of thyrotoxicosis is Graves' disease (GD), an organ-specific autoimmune disease caused by the production of stimulating thyrotropin receptor antibodies. There are three treatment options for thyrotoxicosis: anti-thyroid drugs, radioactive iodine and thyroidectomy. A personalized approach to disease management is especially important in cases of genetic diseases.We present a clinical case of a patient with TS and GD, who has been referred to a radiologist at the Department of Radionuclide Therapy of Endocrinology Research Center. The patient was diagnosed with congenital hypothyroidism at neonatal screening, but thyroid hormones therapy was initiated aged three. Based on the survey, GD was diagnosed aged twenty one. Anti-thyroid drug therapy was started, which resulted in toxic hepatitis. Taking into account intolerance to anti-thyroid drugs, radioiodine therapy has been recommended, which led to hypothyroidism.

Immunological Profile and Autoimmunity in Turner Syndrome

Turner syndrome (TS), characterized by the partial or complete absence of an X-chromosome, provides a unique insight into the role of the X-chromosome and the immune system. While women have a 10-fold higher incidence of autoimmune disease (AD) compared with men, the risk in women with TS is thought to be further doubled. TS is associated with a propensity for a wide variety of ADs that increase in incidence across the life span. Isochromosome Xq as well as isolated Xp deletion karyotypes may predispose to higher rates of AD in TS suggesting the impact of X-chromosome gene dosage. It is likely, however, that epigenetic changes across the genome and the hormonal milieu may also have a profound impact on the immune profile in TS. This review explores the immune phenotype and the spectrum of ADs in TS. Genotype-phenotype correlations are presented with a brief overview of the genetic and hormonal underpinnings.

Histopathological and immunohistochemical changes of the marginal periodontium in patients with Turner syndrome

Turner syndrome (TS) is characterized by partial or complete loss of a sexual chromosome, resulting in an incomplete development of the body, gonadic failure, cardiac and renal abnormalities, oro-dental changes, etc. In our study, we proposed to perform a histological and immunohistochemical (IHC) study of the periodontium changes in patients with TS. The biological material under study was represented by fragments of gingival mucosa harvested from 18 patients with TS who presented advanced periodontal lesions and required dental extractions. The fragments of gingival mucosa were processed by the classical histological technique of paraffin inclusion, subsequently the obtained sections being stained by the Hematoxylin–Eosin (HE) and examined under the optical microscope. For the IHC study, there were performed serial sections incubated with anti-cluster of differentiation (CD) 3, anti-CD20 and anti-CD68 antibodies for highlighting immune cells, as well as with anti-matrix metalloproteinase (MMP) 2 and anti-MMP8 antibodies for highlighting MMPs (MMP2 and MMP8) involved in the periodontal tissue lesions. In the present study, during the histological examination, there were observed morphological changes, both in the epithelium and in the gingival mucosa chorion. Epithelial changes consisted in the onset of acanthosis processes, in the thickening of the epithelium due to the increase of the spinous layer, as well as in the parakeratosis phenomenon. In the chorion, there was observed the presence of inflammatory infiltrates in various stages, presence of fibrosis (extended in some cases) and the presence of an important vascularization in some cases, with a high number of immunocompetent cells involved in the inborn immune response, but also in the adaptive one, as well as a more or less intense immunoexpression of MMP2 and MMP8. Our study suggests that TS may contribute to the development of some inflammatory processes in the marginal periodontium.

Prevalence of Celiac Disease in Patients With Turner Syndrome: Systematic Review and Meta-Analysis

Introduction: Celiac disease (CD) is a multifactorial autoimmune disorder, and studies have reported that patients with Turner syndrome (TS) are at risk for CD. This systematic review and meta-analysis aimed to quantify the weighted prevalence of CD among patients with TS and determine the weighted strength of association between TS and CD.

Methods: Studies published between January 1991 and December 2019 were retrieved from four electronic databases: PubMed, Scopus, Web of Science, and Embase. Eligible studies were identified and relevant data were extracted by two independent reviewers following specific eligibility criteria and a data extraction plan. Using the random-effects model, the pooled, overall and subgroup CD prevalence rates were determined, and sources of heterogeneity were investigated using meta-regression.

Results: Among a total of 1,116 screened citations, 36 eligible studies were included in the quantitative synthesis. Nearly two-thirds of the studies (61.1%) were from European countries. Of the 6,291 patients with TS who were tested for CD, 241 were diagnosed with CD, with a crude CD prevalence of 3.8%. The highest and lowest CD prevalence rates of 20.0 and 0.0% were reported in Sweden and Germany, respectively. The estimated overall weighted CD prevalence was 4.5% (95% confidence interval [CI], 3.3–5.9, I², 67.4%). The weighted serology-based CD prevalence in patients with TS (3.4%, 95% CI, 1.0–6.6) was similar to the weighted biopsy-based CD prevalence (4.8%; 95% CI, 3.4–6.5). The strength of association between TS and CD was estimated in only four studies (odds ratio 18.1, 95% CI, 1.82–180; odds ratio 4.34, 95% CI, 1.48–12.75; rate ratio 14, 95% CI, 1.48–12.75; rate ratio 42.5, 95% CI, 12.4–144.8). Given the lack of uniformity in the type of reported measures of association and study design, producing a weighted effect measure to evaluate the strength of association between TS and CD was unfeasible.

Conclusion: Nearly 1 in every 22 patients with TS had CD. Regular screening for CD in patients with TS might facilitate early diagnosis and therapeutic management to prevent adverse effects of CD such as being underweight and osteoporosis.

Subclinical hypothyroidism in children: updates for pediatricians

Subclinical hypothyroidism (SH) is defined as serum thyroid-stimulating hormone (TSH) above the upper limit of the reference range in the presence of normal free T4 concentrations. Depending on the degree of TSH elevation, SH could be defined as mild (TSH, 4.5-10 mIU/L) or severe (TSH&gt;10 mIU/L). While there is a general consensus to treat children with serum TSH levels above 10 mU/L, the management of the mild form is uncertain and should be individualized. In this mini-review, we present a brief review of SH in children based on extensive literature review and long-standing clinical experience. This review provides the prevalence, causes, clinical presentation, consequences, investigation, and up-to-date therapeutic approach of SH in children. Generally, the purpose of the review is to provide pediatricians with an update of this common and continuously evolving condition.

Hashimoto's Thyroiditis and Graves' Disease in Genetic Syndromes in Pediatric Age

Autoimmune thyroid diseases (AITDs), including Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), are the most common cause of acquired thyroid disorder during childhood and adolescence. Our purpose was to assess the main features of AITDs when they occur in association with genetic syndromes. We conducted a systematic review of the literature, covering the last 20 years, through MEDLINE via PubMed and EMBASE databases, in order to identify studies focused on the relation between AITDs and genetic syndromes in children and adolescents. From the 1654 references initially identified, 90 articles were selected for our final evaluation. Turner syndrome, Down syndrome, Klinefelter syndrome, neurofibromatosis type 1, Noonan syndrome, 22q11.2 deletion syndrome, Prader–Willi syndrome, Williams syndrome and 18q deletion syndrome were evaluated. Our analysis confirmed that AITDs show peculiar phenotypic patterns when they occur in association with some genetic disorders, especially chromosomopathies. To improve clinical practice and healthcare in children and adolescents with genetic syndromes, an accurate screening and monitoring of thyroid function and autoimmunity should be performed. Furthermore, maintaining adequate thyroid hormone levels is important to avoid aggravating growth and cognitive deficits that are not infrequently present in the syndromes analyzed.

Vitamin D receptor (VDR) gene polymorphisms and expression profile influence upon the immunological imbalance in Turner syndrome

PURPOSE

Turner syndrome (TS) patients display considerable immune misregulation, and it is hypothesized that Vitamin D (VTD) activity may fluctuate according to Vitamin D receptor (VDR) polymorphisms and/or expression profile. To uncover a possible relationship between VDR genotype and clinical conditions in TS patients, we investigated two functional VDR variants (Cdx-2 and FokI) for allele and genotype frequencies, as well as expression profile in TS individuals versus healthy controls (HC).

METHODS

We performed a genetic association study including 100 TS patients and 116 HC. Genotyping for VDR Cdx-2 G > A (rs11568820) and FokI C > T (rs2228570) was performed using Taqman Genotyping Assays. VDR gene expression was also evaluated in 15 TS and 15 HC, using fluorogenic probes by qPCR. Statistical analyses were performed using nonparametric Mann-Whitney test, with a 5% significance level (p < 0.05) to uncover differences between groups. In addition, we investigated whether shifted VDR mRNA levels were associated with Cdx-2 and FokI variants in TS patients.

RESULTS

We detected a significantly higher frequency of T allele (p = 0.006) as well as T/T genotype (p = 0.01) for FokI in TS patients when compared to HC. When assessing VDR expression, we identified a downregulation in TS woman (- 2.84 FC) versus HC (p < 0.001). Furthermore, C/T (11.24 FC; p = 0.01) and T/T (9.20 FC; p = 0.01) FokI genotypes were upregulated when compared to C/C reference genotype.

CONCLUSION

TS patients show different distribution of FokI polymorphism. Downregulation of VDR gene expression may contribute to immunological imbalance in TS.

Autoimmune Thyroid Disease in Specific Genetic Syndromes in Childhood and Adolescence

Autoimmune thyroid disease (ATD) is the most frequent cause of acquired thyroid dysfunction, most commonly presenting either as Hashimoto's thyroiditis or Graves' Disease. Hashimoto's thyroiditis is characterized by the presence of thyroid-specific autoantibodies, more commonly anti-thyroperoxidase antibodies in the serum and the typical inhomogeneous echostructure of the thyroid on a thyroid ultrasound examination. Hashimoto's thyroiditis can for a long time be accompanied by normal thyroid function and hypothyroidism can only progressively be established. Graves' disease is much less frequent in childhood and adolescence and presents with overt hyperthyroidism. After the onset of puberty, ATD affects females with a higher incidence than males, while during the prepubertal period there is not such a clear preponderance of affected females. ATD can occur either isolated or in the context of other autoimmune disorders, such as type 1 Diabetes mellitus (T1D), celiac disease, alopecia areata, vitiligo, etc. Especially at the pediatric age, a higher incidence of ATD is also observed in the context of specific genetic syndromes, such as trisomy 21 (Down syndrome), Klinefelter syndrome, Turner syndrome, or 22q11.2 deletion syndrome. Nevertheless, although thyroid dysfunction may also be observed in other genetic syndromes, such as Prader-Willi or Williams syndrome, the thyroid dysfunction in these syndromes is not the result of thyroid autoimmunity. Interestingly, there is emerging evidence supporting a possible link between autoimmunity and RASopathies. In this review article the incidence, as well as the clinical manifestation and accompanied pathologies of ATD in specific genetic syndromes will be presented and regular follow-up for the early identification of the disorder will be proposed.

Autoimmune diseases in Turner syndrome: an overview

Turner syndrome (TS) results from a sex-chromosomal anomaly characterized by presence of one normal X chromosome and the loss of the second X-chromosome in phenotypic females. Autoimmunity has been recognized as one of the more prominent characteristics of TS. The risk of autoimmune diseases in patients with TS is approximately twice as high as in the general female population. The spectrum includes, Hashimoto’s thyroiditis, coeliac disease (CD), type 1 diabetes (T1DM), alopecia areata, inflammatory bowel disease, juvenile rheumatoid arthritis and some cutaneous disorders as vitiligo and Halo nevus. This review will address the autoimmune disorders associated with TS, their pathophysiologic mechanisms and clinical characteristics. (www.actabiomedica.it)

An isolated Xp deletion is linked to autoimmune diseases in Turner syndrome

Background Females with Turner syndrome (TS) are prone to develop autoimmune diseases (AIDs). The X chromosome contains several immune-related genes. Growth hormone (GH) and estrogens modulate the immune system. We aimed to clarify whether the loss of a specific X chromosome gene locus and the administration of GH and estradiol facilitate the development of AIDs in TS females. Methods Retrospective data on clinical course, AIDs, karyotype and treatment were analyzed from a cohort of 286 Czech females with TS (current age 2.8-43.3 years; median age 18.7 years). The karyotypes were sorted using two different classification systems: a mosaicism-focused and an isochromosome (isoXq)-focused approach. Karyotype subgroups with a significantly higher prevalence of AIDs were further evaluated. Data of common therapies were correlated with the prevalence of AIDs. Results The most frequent AIDs were autoimmune thyroid disease (AITD; 37.4%; n = 107) and celiac disease (CD; 8.7%; n = 25). All karyotype subgroups were prone to develop AIDs. Females with an isolated Xp deletion had a significantly higher prevalence of AITD and CD compared to all other individuals with TS (AITD: 66.0% vs. 31.5%, p < 0.0001; CD: 17.4% vs. 7.2%; p = 0.04, respectively). We observed no link between the mean age at initiation as well as the duration of GH and/or estrogen administration and the occurrence of AIDs. Conclusions Isolated Xp deletion contributes to the development of AIDs in TS patients. The haploinsufficiency of genes located in Xpter-p11.2 may explain this observation. Common therapies used in TS do not modify the risk of AIDs.

Autoimmunity Predisposition in Girls With Turner Syndrome

Background: Turner Syndrome is associated with an increased risk of autoimmune diseases, such as autoimmune thyroiditis, coeliac disease, type 1 diabetes mellitus, inflammatory bowel disease, alopecia areata, or vitiligo. The presence of isochromosome iXq and exposure to estradiol may contribute to the development of the autoimmune process. The aim of this study was to determine the prevalence of autoimmune diseases in a group of TS patients and to assess the impact of karyotype and puberty on the development of autoimmune diseases. Patients and Methods: The analysis encompassed clinical and biochemical data of 134 patients treated between 2001 and 2018. All the patients were examined for autoimmune disease symptoms and tested for the presence of antithyroperoxidase (anti-TPO) and antithyreoglobulin (anti-TG) antibodies. In 73 of the patients, anti-transglutaminase (anti-tTG) antibodies were measured. Thyroid function was assessed by measuring TSH and fT4 levels. Results: The mean follow-up was 5.7 ± 3 years. An autoimmune disease was diagnosed in 46 (34.3%) patients: 39 (29.1%) had only one disorder, whilst 7 (5.2%) presented two disorders. The most common disorder, observed in 40 (29.9%) patients, was thyroid autoimmunity. Hashimoto disease was diagnosed in 20 (14.9%) patients. Of the 73 patients tested for coeliac disease, 4 (5.5%) had anti-tTG and 2 (2.7%) presented overt coeliac disease. Vitiligo was diagnosed in 3 (2.2%) patients, type 1 diabetes mellitus or psoriasis were diagnosed in 2 (1.5%) patients, whilst alopecia areata or lichen sclerosus were diagnosed in 1 (0.7%) patient. The impact of karyotype or estradiol exposure on developing autoimmune diseases were not statistically significant. Conclusions: Our study showed a higher incidence of autoimmune diseases in TS, which is in line with the literature; however, the impact of iXq, or spontaneous/inducted puberty was not confirmed.

Prevalence of autoimmune thyroid diseases among the Turner Syndrome patients: meta-analysis of cross sectional studies

Objective

This meta-analysis was done to estimate the prevalence of autoimmune thyroid diseases (ATDs) in Turner Syndrome patients, and to determine the clinical status of thyroid autoimmune diseases that occur frequently in association with Turner Syndrome.

Results

A total of 18 studies were included in the meta-analysis. The pooled overall prevalence of autoimmune thyroid diseases in Turner Syndrome patients was 38.6% (95% CI 29.7–47.6%), with 12.7% (95% CI 9.30–16.1%) of them had clinical hypothyroidism and 2.6% (95% CI 1.5–3.8%) had hyperthyroidism. I-squared test had a high result of heterogeneity. In subgroup analyses, the prevalence of ATDs was higher in the European region than Asian region. Autoimmune thyroid diseases are commonly associated with Turner Syndrome. Early detection of thyroid diseases by optimal screening among children with Turner Syndrome is required to ensure effective management.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3950-0) contains supplementary material, which is available to authorized users.

21-hydroxylase autoantibodies are more prevalent in Turner syndrome but without an association to the autoimmune polyendocrine syndrome type I

Turner syndrome (TS) is associated with an increased frequency of autoimmunity. Frequently observed autoimmune diseases in TS are also seen in the autoimmune polyendocrine syndrome type I (APS I), of which Addison disease is a key component. An overlapping antibody profile between TS and APS I could be considered. The aim of this work was to study women with TS regarding 21-hydroxylase (21-OH) antibodies and interferon omega (IFN-ω) antibodies, a highly specific marker for APS I, to determine if there are immunological overlaps between TS and APS I. Blood samples from 141 TS were assayed for 21-OH antibodies and IFN-ω antibodies using in-vitro-transcribed and translated autoantigen. Indices with a cut-off point of 57 and 200 for 21-OH antibody and IFN-ω antibody were used as reference. The median age of TS was 31·6 years (range = 11·2-62·2). Positive indices of 21-OH antibodies were present in six TS (4%), with a mean of 144·8 (range = 60-535). None had apparent adrenal insufficiency. There was no age difference comparing 21-OH antibody-positive TS (median age = 33·9 years, range = 17·7-44·7) and 21-OH antibody-negative TS (median age = 31·6 years, range = 11·2-62·2) (P = 0·8). No TS was positive for IFN-ω antibodies (mean = 42·4, range = -435-191). No overlapping autoimmune profile between TS and APS I was found. Autoimmunity against 21-OH among TS patients was more prevalent than previously identified, suggesting an increased risk of adrenal failure in TS. However, whether adrenal impairment will develop remains unknown.

Turner Syndrome: transition from childhood to adolescence

Transition from pediatric to adult care for young women with Turner Syndrome (TS) is characterized by high drop-out rates and inadequate follow-up, leading to increased morbidity and mortality. The complexity of the health issues young women with TS face or new problems that may arise warrants a well-structured and efficiently coordinated gradual transition plan, which is adapted to the individual needs of the emerging young adult and is based on interdisciplinary communication between physicians. In order to achieve a high level of care, it is important for the patient to be sincerely informed about her condition but also supported throughout this critical period of rising responsibility and autonomy by an experienced, multidisciplinary team. In this review, we present the basic concepts that should characterize transition and the major health issues that should be thoroughly addressed, including growth, Hormone Replacement Treatment and fertility options, cardiovascular disease, bone health, gastrointestinal disorders, autoimmunity, orthopaedic and ENT issues, as well as the overall psychological well-being of the young adult with TS.

Nationwide Study of Turner Syndrome in Ukrainian Children: Prevalence, Genetic Variants and Phenotypic Features

Objective

We aimed to investigate the prevalence of Turner syndrome (TS) in the Ukrainian population, the frequency of karyotype variants, the age of children at diagnosis, the degree of short stature and phenotypic features in TS girls.

Methods

A retrospective analysis was made in 538 TS girls aged 0.11-18.2 years within the time period of 2005-2015 with detailed examination of 150 patients.

Results

The prevalence of TS in Ukraine is 77.5 in 100.000 live female births. The average age at diagnosis is 9.33±4.93 years. The relative proportions of karyotypic abnormalities found were: 45,X (59.3%); mosaicism 45,X/46,XX (22.9%); and structural abnormalities in chromosome X (17.8%). The most frequently encountered findings were growth delay (98.8%), shortening of the 4th and 5th metacarpal bones (74.6%), abnormal nails (73.3%), broad chest (60.7%), short neck (58.6%), hypertelorism of nipples (51.4%), malformations of the cardiovascular (19.6%) and urinary systems (13.8%) and pathology related to vision (20.1%) and hearing (22.0%).

Conclusion

In the Ukrainian population, the highest proportion of patients with TS had a karyotype 45,X. TS was accompanied by a lower frequency of malformations of internal organs compared to other countries.

Atypical phenotypic aspects of autoimmune thyroid disorders in young patients with Turner syndrome

Aim of this commentary is to analyze the current views about the phenotypic features of Hashimoto’s thyroiditis (HT) and Graves’ disease (GD) in Turner syndrome (TS) girls, in terms of epidemiology, clinical and biochemical presentation, long-term course and metamorphic autoimmunity evolution. In TS GD course is not atypical, whereas HT course is characterized by both a mild presenting picture and a severe long-term evolution of thyroid function tests. Furthermore, TS girls seem to have an increased risk of switching over time from HT to GD. On the light of these findings, it may be concluded that TS girls with HT need a careful monitoring of thyroid status over time.

Conclusions: 1) In children the association with TS is able to condition a peculiar phenotypic expression of HT in terms of epidemiology, presentation course and long-term metamorphic autoimmunity; 2) by contrast, children with TS do not exhibit an atypical clinical and biochemical course of GD, but only a significantly higher prevalence of this disease.

Immunological Profile and Predisposition to Autoimmunity in Girls With Turner Syndrome

OBJECTIVE

The risk of autoimmune diseases (AD) in patients with Turner Syndrome (TS) is twice higher than in the general female population and four times higher than in the male population. The causes of the increased incidence of AD in TS are still under discussion. We hypothesized the presence of a specific humoral, cellular, and regulatory T cell (Treg) immunity profile which predisposes to AD, disorders of immunity, and disorders of immune regulation.

METHODS

The study encompassed 37 girls with TS and with no signs of infection. The control group included 11 healthy girls with no hormonal disorders. A medical history focused on AD and immunity disorders was taken from all participants. The levels of: immunoglobulins IgG, IgA, IgM, total lymphocytes, lymphocytes subpopulations CD3+, CD4+, CD8+, CD19+, natural killer cells, Treg cells (CD4+ CD25+ CD127- FOXP3+), anti-inflammatory cytokines (interleukin-10, transforming growth factor-β), anti-nuclear antibodies, glutamic acid decarboxylase (GAD65 Abs), anti-thyroid peroxidase (anti-TPO Ab), and anti-thyroglobulin (anti-TG Ab) autoantibodies were determined in each participant.

RESULTS

The mean age and BMI in the TS group and in controls were comparable (11.9 ± 4.1 vs. 12.5 ± 4.0 years; 19.2 ± 3.4 vs. 19.7 ± 4.6, p > 0.05). Mean hSDS was significantly higher in controls (-2.2 ± 0.9 vs. -0.4 ± 1.5, p < 0.0001). AD and recurrent otitis media with complications were previously confirmed in 9 (24.3%) and 10 (27.0%) girls with TS. The TS group had significantly lower levels of IgG (p = 0.02), lower%CD4 (p < 0.001) and a significantly lower CD4:CD8 ratio than the controls (p < 0.001). There were no differences in mean Treg% between girls with TS and healthy controls. However, comparing Treg% between the TS group with coexisting autoimmunity and the remaining participants, a statistically significant difference was observed (2.09 ± 0.5 vs. 2.77 ± 1.6, p = 0.048). Patients with iXq had lower CD4% and more frequently had positive anti-TPO Ab and anti-TG Ab compared to the remaining girls with TS and controls (p = 0.001, p < 0.001, p = 0.01).

CONCLUSION

TS predisposes to AD, especially if associated with coexisting iXq. Our preliminary findings show that patients with TS may present a specific profile of humoral and cellular immunity markers, different from healthy girls.

The Turner syndrome life course project: Karyotype-phenotype analyses across the lifespan

INTRODUCTION

Turner syndrome (TS) is associated with a variety of morbidities affecting nearly every body system, some of which increase in prevalence in adult life. The severity of clinical features in TS is roughly in parallel with the magnitude of the deficit of X-chromosome material. The aim of this study was to extend the established karyotype-phenotype relationships using data from a large adult cohort.

MATERIALS AND METHODS

Karyotypes were available in 656 women with TS. 611 of whom could be classified into five major groups within the cohort: 45,X; 45,X mosaicism (45,X/46,XX); isochromosome X (isochromosome Xq); mosaicism 45,X/46,XY and ring X. Continuous variables such as blood pressure and biochemical markers from clinic data were binarised allocating those in the upper quartile to represent at-risk individuals. With the exception of bone mineral density T-score for which the lower quartile was allocated as at risk. For comorbidities, initiation of formal treatment was recorded.

RESULTS

45,X/46,XX had considerably lower frequency of comorbidities compared to 45,X. The isochromosome group experienced similar outcomes to 45,X. Novel associations were found between the XY mosaic karyotype group and a decreased prevalence of thyroid disease and severe hearing loss. A previously unreported increased incidence of metabolic syndrome was noted within the ring chromosome subgroup.

CONCLUSIONS

Karyotype may play an important factor against stratifying risk of comorbidity in TS and should be taken into consideration when managing adults with TS. Further investigations of the isochromosome (Xq) and ring groups are necessary to further clarify their associations with comorbidities.

Seronegative Myasthenia Gravis, as a Rare Autoimmune Condition in Turner Syndrome

Girls with Turner syndrome (TS), especially with isochromosome 46,X,i(X)(q10), are prone to develop autoimmunity. Associations of several autoimmune conditions with TS have been frequently described in the past. However, the unique combination of TS and myasthenia gravis (MG) has been reported only once before in a girl with mosaic monosomy 45,X/46,XX. Here, we present the second case of a girl affected with seronegative MG but with mosaic isochromosome TS. This is a child with developmental delay presented with muscle weakness, frequent fall, and bilateral ptosis. Diagnosis of MG was made based on positive Tensilon and electromyography tests and excellent response to intravenous immunoglobulin. At the age of 11 years due to short stature and developmental delay, a karyotype was done and revealed the mosaic isochromosome 45,X/46,X,i(X)(q10). Overall, clinicians should be aware of the vulnerability of girls with TS to autoimmunity, especially if the isochromosome 46,X,i(X)(q10) karyotype is identified. Furthermore, if a child with TS develops muscle weakness, ptosis, or ophthalmoplegia, MG should also be included in the differential diagnosis, particularly if other concurrent autoimmune conditions are present.

Pituitary Antibodies in an Adolescent with Secondary Adrenal Insufficiency and Turner Syndrome

BACKGROUND/AIMS

Autoimmune hypophysitis (AH) is a rare inflammatory disease of the pituitary gland causing varying degrees of hypopituitarism and/or sellar compression. Cranial MRI remains the best noninvasive tool to diagnose AH, although a diagnosis of certainty requires pituitary biopsy. The objective of this study was to assess the utility of detecting pituitary antibodies for the diagnosis of AH.

METHODS

A 15-year-old female with Turner syndrome (TS), hypothyroidism, and ovarian failure presented acutely with hypocortisolism. Laboratory studies revealed secondary adrenal insufficiency. MRI showed a hypotrophic pituitary gland and loss of the posterior pituitary bright spot. To establish an autoimmune basis for the adrenal insufficiency, serum was analyzed by double indirect immunofluorescence for the presence of pituitary autoantibodies.

RESULTS

The patient's serum contained autoantibodies that recognized 36% of the adrenocorticotropic hormone-secreting cells, suggesting that these adenohypophyseal cells were targeted by autoimmunity. The serum contained antibodies that identified the majority of the gonadotropin-secreting cells (FSH 77%, LH 65%). No recognition of GH-, prolactin-, and TSH-secreting cells was found. Preabsorption experiments showed that antigenic targets of autoantibodies were not anterior pituitary hormones themselves.

CONCLUSION

Demonstration of circulating pituitary antibodies expands the diagnostic options for AH. In this adolescent with TS, positive and cell-specific pituitary antibodies suggested that AH was the cause of her secondary adrenal insufficiency.

Five-year prospective evaluation of thyroid function in girls with subclinical mild hypothyroidism of different etiology

AIM

To follow-up for 5 years thyroid status evolution in 127 girls with mild (TSH 5-10 mU/l) subclinical hypothyroidism (SH) of different etiologies.

PATIENTS

The population was divided into two age-matched groups of 42 and 85 girls with either idiopathic (group A) or Hashimoto's thyroiditis (HT)-related SH (group B). Group B was in turn divided into three subgroups, according to whether SH was either isolated or associated with Turner syndrome (TS) or Down syndrome (DS).

RESULTS

At the end of follow-up the rate of girls who became euthyroid was higher in group A (61.9% vs 10.6%), whereas the rates of patients who remained SH (55.3% vs 26.2%), became overtly hypothyroid (30.6% vs 11.9%) or required levothyroxine (l-T4) therapy (63.5% vs 23.8%) were higher in group B. Among the girls of group B, the risk of remaining SH or developing overt hypothyroidism was higher in the subgroups with TS or DS than in those with isolated HT.

CONCLUSIONS

Long-term prognosis of mild and idiopathic SH is frequently benign, even though a l-T4 treatment may be needed throughout follow-up in almost a quarter of cases; long-term prognosis is different in the girls with either idiopathic or HT-related SH; and the association with either TS or DS impairs the outcome of HT-related SH.

The association with Turner syndrome significantly affects the course of Hashimoto's thyroiditis in children, irrespective of karyotype

Only few studies have investigated to now whether the association with Turner syndrome (TS) may affect the course of Hashimoto's thyroiditis (HT) in children. Aim of this study was to ascertain whether the presentation and long-term course of HT in TS children may be characterized by a peculiar and atypical pattern. The clinical and biochemical findings at HT diagnosis in 90 TS children (group A) were compared with those recorded in 449 girls with HT but without TS (group B); in group A patients, thyroid function tests were re-evaluated after a median time interval of 4.9 years. At HT diagnosis median TSH levels and the rate of cases presenting with a thyroid dysfunction picture were significantly lower in group A, irrespective of karyotype abnormalities. In group A only 34.8 % of the girls who had initially presented with euthyroidism remained euthyroid even at re-evaluation, whilst 67.7 % of those who had presented with subclinical hypothyroidism became overtly hypothyroid over time; also such evolutive pattern was irrespective of karyotype abnormalities. (1) In TS girls, HT presents with a milder hormonal pattern, which often deteriorates over time; (2) these biochemical features are not necessarily linked with a specific karyotype.

Heterogeneous phenotype in children affected by non-autoimmune hypothyroidism: an update

BACKGROUND

In the last decades, a higher incidence of congenital hypothyroidism (CH) has been recorded in Italy (1:1940) and worldwide, mainly due to the shift to lower screening TSH cutoffs. Although CH can also be caused by dysgenetic defects, most CH cases have recently been found to be more frequently associated with functional defects of an in situ thyroid gland. Although the clinical phenotype is milder with high prevalence of transient forms, some cases eventually prove to be permanent.

RESULTS

Possible explanations of the raised incidence of CH are ethnic modifications of the screened population and the increasing incidence of preterm birth and multiple pregnancies. These findings are important in terms of public health and standardization of screening programmes for special at-risk categories such as preterms, acutely ill term neonates, low birth weight and very low birth weight infants, and newborns with specific drug exposure. Other environmental factors have contributed to the increased incidence of hypothyroidism, including thyroid disrupting chemicals, iodine supply (excess/deficiency), and drugs interfering with thyroid function. Finally, an increased prevalence of hypothyroidism has been documented in obese children and patients with syndromic forms (Williams, Down, Turner, pseudohypoparathyroidism). The clinical and molecular phenotype of patients with CH will be better defined thanks to novel genetic approach based on the systematic analysis of a panel of genes (TSHR, DUOX2, DUOXA, TPO, PDS, TG, NKX2.1, JAG1, GLIS3, FOXE1, PAX-8).

CONCLUSIONS

This review summarizes significant advances in the epidemiology and aetiology of non-autoimmune hypothyroidism, with a focus on thyroid dysfunction in preterm infants.

Complex X chromosome rearrangement associated with multiorgan autoimmunity

BACKGROUND

Turner syndrome, a congenital condition that affects 1/2,500 births, results from absence or structural alteration of the second sex chromosome. Turner syndrome is usually associated with short stature, gonadal dysgenesis and variable dysmorphic features. The classical 45,X karyotype accounts approximately for half of all patients, the remainder exhibit mosaicism or structural abnormalities of the X chromosome. However, complex intra-X chromosomal rearrangements involving more than three breakpoints are extremely rare.

RESULTS

We present a unique case of a novel complex X chromosome rearrangement in a young female patient presenting successively a wide range of autoimmune diseases including insulin dependent diabetes mellitus, Hashimoto's thyroiditis, celiac disease, anaemia perniciosa, possible inner ear disease and severe hair loss. For the genetic evaluation, conventional cytogenetic analysis and FISH with different X specific probes were initially performed. The complexity of these results and the variety of autoimmune problems of the patient prompted us to identify the exact composition and breakpoints of the rearranged X as well as methylation status of the X chromosomes. The high resolution array-CGH (assembly GRCh37/hg19) detected single copy for the whole chromosome X short arm. Two different sized segments of Xq arm were present in three copies: one large size of 80,3 Mb from Xq11.1 to Xq27.3 region and another smaller (11,1 Mb) from Xq27.3 to Xq28 region. An 1,6 Mb Xq27.3 region of the long arm was present in two copies. Southern blot analysis identified a skewed X inactivation with ≈ 70:30 % ratios of methylated/unmethylated fragments. The G-band and FISH patterns of the rearranged X suggested the aspect of a restructured i(Xq) chromosome which was shattered and fortuitously repaired. The X-STR genotype analysis of the family detected that the patient inherited intact maternal X chromosome and a rearranged paternal X chromosome. The multiple Xq breakages and fusions as well as inverted duplication would have been expected to cause a severe Turner phenotype. However, the patient lacks many of the classic somatic features of Turner syndrome, instead she presented multiorgan autoimmune diseases.

CONCLUSIONS

The clinical data of the presented patient suggest that fragmentation of the i(Xq) chromosome elevates the risk of autoimmune diseases.

Peculiarities of autoimmune thyroid diseases in children with Turner or Down syndrome: an overview

Aim of this commentary is to summarize the salient literature news on the relationships between autoimmune thyroid diseases (ATDs) and either Down syndrome (DS) or Turner syndrome (TS).According to literature reports both Hashimoto's thyroiditis (HT) and Graves' disease (GD) are more frequent in children with DS or TS than in those without these chromosomopathies.An up-regulation of proinflammatory cytokines might be responsible for the enhanced susceptibility of TS children to ATDs, whereas a dysregulation of immune system may favor the development of ATDs in DS.In TS children biochemical presentation of HT is less severe than in peer controls. In both DS and TS GD picture at the time of diagnosis is not significantly different than in the pediatric general population.The evolution over time of GD in DS and TS does not differ from that observed in the pediatric general population, whereas the evolution of HT in both TS and DS is more severe than in girls without these chromosomopathies.

CONCLUSIONS

The association with TS or DS is able to affect both epidemiology and course of ATDs by conditioning: a) an increased susceptibility to these disorders; b) a less severe biochemical presentation and a more severe evolutive pattern of HT in TS girls; c) a more severe biochemical presentation and evolution of HT in DS patients.

Turner syndrome and associated problems in Turkish children: a multicenter study

OBJECTIVE

Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.

METHODS

Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.

RESULTS

The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.

CONCLUSION

This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan.

Turner syndrome--issues to consider for transition to adulthood

BACKGROUND

Turner syndrome (TS) is associated with a spectrum of health problems across the age span, which requires particular attention during the transition period in these adolescents.

AREAS OF AGREEMENT

The majority of girls with TS require oestrogen replacement from puberty onwards, which is important for adequate feminization, uterine development and maintenance of bone health. There is a lifetime increased risk from autoimmune conditions like hypothyroidism, coeliac disease, hearing loss and aortic dilatation with the potential to lead to aortic dissection. A systematic and holistic approach to provision of health care in TS is needed.

AREAS OF CONTROVERSY

Several unanswered questions remain, including the choice of hormone replacement therapy in the young person with TS and in adulthood; the optimal mode of cardiovascular assessment; the best management and assessment prior to and during pregnancy.

AREAS TIMELY FOR DEVELOPING RESEARCH

The optimal model of care and transition to adult services in TS requires attention. Further research is needed in relation to cardiovascular risk assessment, pregnancy management and hormone replacement therapy in TS.

Turner syndrome: update on biology and management across the life span

PURPOSE OF REVIEW

We review recent understanding of the pathophysiology, molecular biology, and management of Turner syndrome.

RECENT FINDINGS

Sophisticated genetic techniques are able to detect mosaicism in one-third of individuals previously thought to have monosomy X. Prenatal detection using maternal blood should permit noninvasive detection of most fetuses with an X chromosome abnormality. Disproportionate growth with short limbs has been documented in this condition, and a target gene of short stature homeobox, connective tissue growth factor (Ctgf), has been described. Liver disease is more common in Turner syndrome than previously recognized. Most girls have gonadal failure. Spontaneous puberty and menarche is more commonly seen in girls with XX mosaicism. Low-dose estrogen replacement therapy may be given early to induce a more normal onset and tempo of puberty. Oocyte donation for assisted reproduction carries a substantial risk, particularly if the woman has known cardiac or aortic disease. Neurodevelopmental differences in Turner syndrome are beginning to be correlated with differences in brain anatomy.

SUMMARY

An increased understanding of the molecular basis for aspects of this disorder is now developing. In addition, a renewed focus on health maintenance through the life span should provide better general and targeted healthcare for these girls and women.

Progress in pediatrics in 2013: choices in allergology, endocrinology, gastroenterology, hypertension, infectious diseases, neonatology, neurology, nutrition and respiratory tract illnesses

This review will provide new information related to pathophysiology and management of specific diseases that have been addressed by selected articles published in the Italian Journal of Pediatrics in 2013, focusing on allergology, endocrinology, gastroenterology, hypertension, infectious diseases, neonatology, neurology, nutrition and respiratory tract illnesses in children. Recommendations for interpretation of skin prick test to foods in atopic eczema, management of allergic conjunctivitis, hypertension and breastfeeding in women treated with antiepileptic drugs and healthy breakfast have been reported. Epidemiological studies have given emphasis to high incidence of autoimmune disorders in patients with Turner syndrome, increasing prevalence of celiac disease, frequency of hypertension in adolescents, incidence and risk factor for retinopathy of prematurity. Advances in prevention include elucidation of the role of probiotics in reducing occurrence of allergies and feeding intolerance, and events of foetal life that influence later onset of diseases. Mechanistic studies suggested a role for vitamin D deficiency in asthma and type 1 diabetes and for reactivation of Varicella-Zoster virus in aseptic meningitis. Regarding diagnosis, a new mean for the diagnosis of hyperbilirubinaemia in newborns, a score for recognition of impaired nutritional status and growth and criteria for early Dyke-Davidoff-Masson Syndrome have been suggested. New therapeutic approaches consist of use of etanercept for reducing insulin dose in type 1 diabetes, probiotics in atopic eczema, and melatonin in viral infections.