Down syndrome and thyroid function

Van Wyk-Grumbach Syndrome and Gonadectomy

Van Wyk-Grumbach syndrome (VWGS) refers to the development of peripheral precocious puberty, long-standing hypothyroidism, and gonadal masses; when not diagnosed, an unnecessary gonadectomy may be performed. Herein, we present a case of a 10-year-old girl with Down's syndrome, short stature, and vitiligo who presented to our hospital with vaginal bleeding and a palpable pelvic mass. Upon ultrasound and topographical examination, bilateral ovarian masses with negative tumor markers were detected. After bilateral gonadectomy, endocrine studies revealed profound hypothyroidism and peripheral puberty that led to the VWGS syndrome diagnosis (TSH 367.3 mUI/mL, isolated menstruation, indetectable LH, and elevated estradiol). Levothyroxine treatment improved obesity and short stature, and sexual hormone replacement began at 13 years of age. The literature on Van Wyk-Grumbach syndrome shows that it presents most often in women, and classic hypothyroidism symptoms always precede the diagnosis. Approximately 11% of patients have Down's syndrome, sometimes tumor markers are elevated, and some develop severe symptoms (myopathy, short stature, mental delay, ascites, pericardial effusion, Cullen's sign, pituitary hyperplasia, and severe anemia) that respond to levothyroxine treatment. Conclusions: Children with peripheral precocious puberty and gonadal masses must be studied for hypothyroidism before any radical decision is made.

Down Syndrome and Autoimmune Disease

Down syndrome is the most common genetic cause of intellectual disability and has previously been associated with a variety of autoimmune disorders affecting multiple organ systems. The high prevalence of autoimmune disease, in conjunction with other inflammatory and infectious diseases, in this population suggests an intrinsic immune dysregulation associated with triplication of chromosome 21. Emerging data on the role of chromosome 21 in interferon activation, cytokine production, and activation of B-cell mediated autoimmunity are emerging hypotheses that may explain the elevated prevalence of autoimmune thyroid disease, celiac disease, type I diabetes, autoimmune skin disease, and a variety of autoimmune neurologic conditions. As the life expectancy for individuals with Down syndrome increases, knowledge of the epidemiology, clinical features, management and underlying causes of these conditions will become increasingly important. Disorders such as Hashimoto's thyroiditis are prevalent in between 13 and 34% of individuals with Down syndrome but only 3% of the neurotypical population, a pattern similarly recognized in individuals with Celiac Disease (5.8% v 0.5-2%), alopecia areata (27.7% v. 2%), and vitiligo (4.4% v. 0.05-1.55%), respectively. Given the chronicity of autoimmune conditions, early identification and management can significantly impact the quality of life of individuals with Down syndrome. This comprehensive review will highlight common clinical autoimmune conditions observed in individuals with Down syndrome and explore our current understanding of the mechanisms of disease in this population.

Pregnancy, delivery, and neonatal outcomes among women living with Down syndrome: a matched cohort study, utilizing a population database

PURPOSE

We utilized a population database to address the paucity of data around pregnancy outcomes in women with Down syndrome (DS).

METHODS

We conducted a retrospective study using the Health Care Cost and Utilization Project-Nationwide Inpatient Sample Database over 11 years, from 2004 to 2014. A delivery cohort was created using ICD-9 codes. ICD-9 code 758.0 was used to extract the cases of maternal DS. Pregnant women with DS (study group) were matched based on age, race, income, and health insurance type to women without DS (control) at a ratio of 1:20.

RESULTS

There were a total of 9,096,788 deliveries during the study period. Of those, 184 pregnant women were found to have DS. The matched control group was 3680. After matching, most of the pregnancy and delivery outcomes, such as pregnancy-induced hypertension, gestational diabetes, preterm premature rupture of membrane, chorioamnionitis, cesarean section, operative vaginal delivery, or blood transfusion were similar between participants with and without DS. However, patients with DS were at increased risk of giving birth prematurely (aOR 3.09, 95% CI 2.06-4.62), and having adverse neonatal outcomes such as small for gestational age (aOR 2.70, 95% CI 1.54-4.73), intrauterine fetal demise (aOR 22.45, 95% CI 12.02-41.93), congenital anomalies (aOR 7.92, 95% CI 4.11-15.24), and fetal chromosomal abnormalities.

CONCLUSION

Neonates to mothers with DS are at increased risk of prematurity and other neonatal adverse outcomes. Hence, counseling patients with DS about these risks and increased antenatal surveillance is advised.

Hypothyroidism in Patients with Down Syndrome: Prevalence and Association with Congenital Heart Defects

This population-based study aimed to assess the prevalence of congenital hypothyroidism (CH) and overt hypothyroidism (OH) and their association with congenital heart defects (CHDs) in patients with Down syndrome (DS). The population included all live births residing in Tuscany (Italy) diagnosed with DS recorded in the Registry of Congenital Defects and in the Registry of Rare Diseases of Tuscany in the years 2003-2017. The prevalence of CH and OH in DS patients was calculated by sex and by period. The association of CH and OH with CHDs in DS patients was assessed using multivariate logistic regression. The cohort included 228 subjects. The prevalence of CH and OH was 11.4% (95%CI: 7.4-16.7%) and 12.7% (95%CI: 8.5-12.3%), respectively, with no significant difference by sex. A significant increase in the prevalence of CH (p < 0.0001) was found in the years 2010-2017 compared to the previous period, and among preterm infants (p = 0.009). The presence of CH was associated with a higher prevalence of CHDs (adjusted OR = 2.24, p = 0.082). A significant association between ventricular septal defects (VSDs) and the occurrence of OH (adjusted OR = 3.07, p = 0.025) was also observed. This study confirmed the higher prevalence of both CH and OH in DS compared to the general population. Furthermore, the risk of association between DS and CHDs was higher in the presence of CH, while VSDs are associated with OH, providing relevant insights into the epidemiology of hypothyroidism in DS and associated anomalies.

Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life

Down syndrome (DS) is the most common chromosomal disorder worldwide. Along with intellectual disability, endocrine disorders represent a remarkable share of the morbidities experienced by children, adolescents and young adults with DS. Auxological parameters are plotted on syndrome-specific charts, as growth rates are reduced compared to healthy age- and gender-matched peers. Furthermore, children with DS are at increased risk for thyroid dysfunctions, diabetes mellitus, osteopenia and obesity compared to general population. Additionally, male individuals with DS often show infertility, while women tend to experience menopause at an overall younger age than healthy controls. Given the recent outstanding improvements in the care of severe DS-related comorbidities, infant mortality has dramatically decreased, with a current average life expectancy exceeding 60 years. Accordingly, the awareness of the specificities of DS in this field is pivotal to timely detect endocrine dysfunctions and to undertake a prompt dedicated treatment. Notably, best practices for the screening and monitoring of pediatric endocrine disorders in DS are still controversial. In addition, specific guidelines for the management of metabolic issues along the challenging period of transitioning from pediatric to adult health care are lacking. By performing a review of published literature, we highlighted the issues specifically involving children and adolescent with DS, aiming at providing clinicians with a detailed up-to-date overview of the endocrine, metabolic and auxological disorders in this selected population, with an additional focus on the management of patients in the critical phase of the transitioning from childhood to adult care.

Thyroid Function Tests in Children and Adolescents With Trisomy 21: Definition of Syndrome-Specific Reference Ranges

CONTEXT

The lack of syndrome-specific reference ranges for thyroid function tests (TFT) among pediatric patients with Down syndrome (DS) results in an overestimation of the occurrence of hypothyroidism in this population.

OBJECTIVE

To (a) outline the age-dependent distribution of TFT among pediatric patients with DS; (b) describe the intraindividual variability of TFT over time; and (c) assess the role of elevated thyrotropin (TSH) in predicting the future onset of overt hypothyroidism.

METHODS

In this retrospective, monocentric, observational analysis, we included 548 patients with DS (0-18 years) longitudinally assessed between 1992 and 2022. Exclusion criteria were abnormal thyroid anatomy, treatments affecting TFT, and positive thyroid autoantibodies.

RESULTS

We determined the age-dependent distribution of TSH, FT3, and FT4 and outlined the relative nomograms for children with DS. Compared with non-syndromic patients, median TSH levels were statistically greater at any age (P < .001). Median FT3 and FT4 levels were statistically lower than controls (P < .001) only in specific age classes (0-11 for FT3, 11-18 years for FT4). TSH levels showed a remarkable fluctuation over time, with a poor (23%-53%) agreement between the TSH centile classes at 2 sequential assessments. Finally, the 75th centile was the threshold above which TSH values predicted future evolution into overt hypothyroidism with the best statistical accuracy, with a satisfactory negative predictive value (0.91), but poor positive predictive value (0.15).

CONCLUSION

By longitudinally assessing TFT in a wide pediatric DS population, we outlined the syndrome-specific reference nomograms for TSH, FT3, and FT4 and demonstrated a persistent upward shift of TSH compared to non-syndromic children.

Selenium level correlates negatively with antibodies but positively with thyroid function in children with down syndrome: an Indonesian study

Background

Children with Down syndrome (DS) are prone to developing autoimmune thyroid disease (AITD). Previous studies found lower selenium (Se) levels in children with AITD. Glutathione peroxidase-3 (GPx3) and selenoprotein-P (SePP) are widely used to measure Se levels. DS children tend to have lower Se levels, the main contributor to hypothyroidism in this population. This study aimed to analyze the Se's role in AITD in Indonesian children with DS.

Methods

This cross-sectional study was conducted between February 2021-June 2022 at the Pediatric Outpatient Clinic of Dr Soetomo Hospital. DS children aged 1 month to 18 years were enrolled using consecutive sampling. Thyroid-stimulating hormone, free thyroxine, thyroid peroxidase (TPO-Ab) and thyroglobulin (Tg-Ab) autoantibody, GPx3, and SePP levels were measured in plasma samples using enzyme-linked immunosorbent assays. Statistical analyses used Chi-square, Mann-Whitney, and Spearman's rank correlation (r _s). All results with p<0.05 were considered statistically significant.

Results

Among 62 children with DS, SePP and GPx3 levels were significantly lower in those with AITD than those without AITD (p=0.013 and p=0.018, respectively). SePP and GPx3 levels correlated significantly with lower TPO-Ab (r _s=-0.439 with p=1×10^-5 and r _s=-0.396 with p=0.001, respectively) and Tg-Ab (r _s=-0.474 with p=1×10^-5 and r _s=-0.410 with p=0.001, respectively) levels. SePP levels correlated significantly with lower thyroid dysfunction incidence (r _s=-0.252, p=0.048) in the AITD group.

Conclusion

Selenium deficiency contributes to autoimmune process in the thyroid and to thyroid dysfunction in children with Down syndrome. Our findings recommend increasing Se levels through Se-containing foods to reduce the risks of AITD and thyroid dysfunction in DS children with AITD.

Endocrine Disorders in a Newborn with Heterozygous Galactosemia, Down Syndrome and Complex Cardiac Malformation: Case Report

Down syndrome is the most common chromosomal abnormality diagnosed in newborn babies. Infants with Down syndrome have characteristic dysmorphic features and can have neuropsychiatric disorders, cardiovascular diseases, gastrointestinal abnormalities, eye problems, hearing loss, endocrine and hematologic disorders, and many other health issues. We present the case of a newborn with Down syndrome. The infant was a female, born at term through c-section. She was diagnosed before birth with a complex congenital malformation. In the first few days of life, the newborn was stable. In her 10th day of life, she started to show respiratory distress, persistent respiratory acidosis, and persistent severe hyponatremia, and required intubation and mechanical ventilation. Due to her rapid deterioration our team decided to do a screening for metabolic disorders. The screening was positive for heterozygous Duarte variant galactosemia. Further testing on possible metabolic and endocrinologic issues that can be associated with Down syndrome was performed, leading to hypoaldosteronism and hypothyroidism diagnoses. The case was challenging for our team because the infant also had multiple metabolic and hormonal deficiencies. Newborns with Down syndrome often require a multidisciplinary team, as besides congenital cardiac malformations they can have metabolic and hormonal deficiencies that can negatively impact their short- and long-term prognosis.

Down Syndrome for the Otolaryngologist: A Review

Importance

There are many features of Down syndrome that prompt referral to an otolaryngologist. As the lifetime prevalence and life expectancy of individuals with Down syndrome increase, it is increasingly likely that otolaryngologists will have the opportunity to care for patients with Down syndrome.

Observations

A confluence of characteristics common to Down syndrome may be associated with issues in the head and neck, from infancy through adulthood. Hearing concerns range from narrow ear canals and cerumen impactions to eustachian tube dysfunction, middle ear effusion, cochlear malformations, and conductive, sensorineural, and/or mixed hearing loss. Immune deficiency, hypertrophy of Waldeyer ring, and hypoplastic sinuses may complicate and develop into chronic rhinosinusitis. Speech delay, obstructive sleep apnea, dysphagia, and airway anomalies are also common among this patient population. Because these concerns may necessitate otolaryngologic surgery, it is vital for otolaryngologists to familiarize themselves with anesthetic concerns, including cervical spine instability, in patients with Down syndrome. Comorbid cardiac disease, hypothyroidism, and obesity may also affect these patients and otolaryngologic care.

Conclusions and Relevance

Individuals with Down syndrome may visit otolaryngology practices at all ages. Otolaryngologists that familiarize themselves with the head and neck manifestations that are common among patients with Down syndrome and know when to order screening tests will be able to provide comprehensive care.

Protein tyrosine phosphatase non-receptor type 22 C1858T gene polymorphism in children with down syndrome and autoimmune thyroid diseases

Autoimmune Thyroid Disease (AIT) is a frequent comorbidity in Down Syndrome (DS). Protein Tyrosine Phosphatase Non- Receptor Type 22 C1858T (PTPN-22 C1858T) gene polymorphisms have a role in the progression of AIT. The study on PTPN- 22 C1858T gene polymorphism as the risk factor of AIT in DS children is still limited. This study aims to evaluate PTPN-22 C1858T polymorphism in Indonesian DS children. A cross-sectional study involving 31 DS children with hypothyroidism (19 boys/12 girls) was conducted for ten months from February to November 2020 at Dr. Soetomo General Hospital Surabaya. The PTPN-22 C1858T gene polymorphism was analyzed using Polymerase Chain Reaction-Restriction-Fragment-Length Polymorphism (PCR-RFLP). Anti-Thyroid Peroxidase (Anti- TPO) and Anti-Thyroglobulin (Anti-TG), FT4, T3, and TSH levels were analyzed using Enzyme-Linked-Immunosorbent-Assay (ELISA). The mean age of the subjects was 19.45±17.3 months. The CT variant of PTPN-22 C1858T was observed in all subjects. The mean level of T3, FT4, and TSH were 1.59±0.45 ng/mL, 0.81±0.57 ng/mL, 0.22±0.21 μU/mL, respectively. Around 83.9% of patients suffered from central hypothyroidism, 12.9% from primary hypothyroidism, and 3.2% from subclinical hypothyroidism. The positive anti-TG and anti-TPO were observed in 96.8% and 58.1%, respectively. CT variant was observed in Indonesian DS children who suffered from hypothyroidism.

Nutrition as Prevention of Diet-Related Diseases-A Cross-Sectional Study among Children and Young Adults with Down Syndrome

BACKGROUND

The aim of this study was to assess the diet of children with Down syndrome (DS) and to identify potential dietary mistakes made by their parents.

MATERIALS AND METHODS

The study was conducted among 195 parents of people with DS between November 2020 and March 2021. Data for the study were collected anonymously using the CAWI method.

RESULTS

122 (62.6%) people with DS did not eliminate any nutrient from their diet. By contrast, in the study group, the following numbers of people reported the following dietary restrictions: 51 (26.2%) gluten, 56 (28.7%) lactose, 17 (8.7%) casein, 26 (13.3%) sucrose, 2 (1.0%) histamine, 2 (1.0%) lectins, and 1 (0.5%) dairy. The most frequent response for vegetable and fruit consumption was once a day, with 83 (42.6%) and 87 (44.6%) parents indicating this. The most frequent response for dairy product consumption was every day, with 72 (36.9%) parents indicating this, while 36 (20%) parents stated that their children do not eat dairy products at all. In the study group, the most frequent response for meat consumption was several times a week, this was indicated by 107 (54.9%) parents, while 1 (0.5%) of them said that their children do not eat meat products at all. The most frequent response for fish consumption was 1-2 times a week, this answer was indicated by 101 (51.8%) parents, while 13 (6.7%) said that their children do not eat these products at all.

CONCLUSIONS

A majority of the subjects with DS are usually fed in a normal way, but nutritional mistakes are made by the parents. Special attention should be paid to prolonging the period of natural feeding.

The Use of Virtual and Computational Technologies in the Psychomotor and Cognitive Development of Children with Down Syndrome: A Systematic Literature Review

Individuals with Down syndrome (DS) have numerous comorbidities due to trisomy 21. However, virtual reality-based therapy (VRT) has been used nowadays as a learning and visual motor tool in order to facilitate the development and learning process of this group. The aim of this article was to carry out an integrative review of the literature on the use of virtual and computational technologies in the stimulation of children with DS. A search was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) through single key words or their combinations using AND or OR operators: “Down syndrome” AND (“development” OR “cognition” OR “visomotor” OR “digital game” OR “virtual reality”). Eventually, 18 articles were included in our review. The games used in the research were able to stimulate, through the visual field, global motor skills, balance, body scheme and spatial organization, in addition to the learning of mathematical concepts, in order to directly influence the autonomous life activities, language skills, social skills and educational aspects of people with DS. Electronic games contribute to the teaching-learning relationship and stimulate neuropsychomotor and cognitive functions and development in children with DS.

Endocrinal dysfunction in children with Down syndrome

Down syndrome (DS) is the most common genetic disorder in live-born infants. Children with DS are at increased risk of numerous endocrinal comorbidities. The information contained in this article will provide pediatricians with a narrative overview of different presentations, diagnoses, and management recommendations of various endocrinal disorders in children with DS. We systematically searched PubMed, Embase, Google Scholar, MEDLINE, EBSCO, and Science Direct, and potentially relevant articles were identified and retrieved from electronic and print journals.

Quantification of serum thyroid hormones using tandem mass spectrometry in patients with Down syndrome

Thyroid dysfunction is common in patients with Down syndrome (DS), the most common chromosomal disorder. Thyroid hormones (THs) are important for normal growth, neurodevelopment, and metabolism, highlighting the importance of quantifying the levels in patients with DS. However, current methods possess cross-reactivity that results in inaccuracies in quantification. We aimed at developing a new analytical method for quantifying the total 3,3',5-triiodo-l-thyronine (TT3), total 3,3',5,5'-tetraiodo-l-thyronine (TT4), 3,3',5'-triiodo-l-thyronine, and reverse T3 (rT3) levels using LC-MS/MS. Repeatability and reproducibility with coefficient of variation values of 2-9 and 3-13%, respectively, were acceptable, suggesting that the assay was suitable for measuring serum THs. We measured the serum TH levels of patients with DS but without thyroid dysfunction (age, 3-20 years) and compared the levels to those of controls (patients with idiopathic short stature; age, 3-17 years). When TH levels were summarized by age group, the serum TT4 concentrations were not significantly different between the controls and patients with DS across all age groups. Meanwhile, the serum TT3 concentrations differed according to age. In addition, the serum rT3 concentrations were significantly higher in patients with DS than in controls, except for those in the 12-14 age group. We also calculated the T3/T4 and rT3/T4 ratios to elucidate the reason for the higher rT3 in patients with DS; however, no useful findings were obtained. Thus, further investigation is needed to clarify our findings.

Metabolic Diseases and Down Syndrome: How Are They Linked Together?

Down syndrome is a genetic disorder caused by the presence of a third copy of chromosome 21, associated with intellectual disabilities. Down syndrome is associated with anomalies of both the nervous and endocrine systems. Over the past decades, dramatic advances in Down syndrome research and treatment have helped to extend the life expectancy of these patients. Improved life expectancy is obviously a positive outcome, but it is accompanied with the need to address previously overlooked complications and comorbidities of Down syndrome, including obesity and diabetes, in order to improve the quality of life of Down syndrome patients. In this focused review, we describe the associations between Down syndrome and comorbidities, obesity and diabetes, and we discuss the understanding of proposed mechanisms for the association of Down syndrome with metabolic disorders. Drawing molecular mechanisms through which Type 1 diabetes and Type 2 diabetes could be linked to Down syndrome could allow identification of novel drug targets and provide therapeutic solutions to limit the development of metabolic and cognitive disorders.

Subclinical Hypothyroidism as the Most Common Thyroid Dysfunction Status in Children With Down's Syndrome

INTRODUCTION

Thyroid dysfunctions are one of the most common abnormalities coexisting in children with Down's syndrome (DS) and have been reported in up to 54% of cases.

AIM OF THE STUDY

The purposes of this retrospective study were to investigate the course of subclinical hypothyroidism in children with DS, to evaluate the thyroid function of these subjects in relation to the risk of developing overt thyroid disease and autoimmunity, and to identify clinical and biochemical characteristics of patients prescribed L-T4 therapy in children and adolescents with DS and SH.

MATERIAL AND METHODS

The records of DS patients referred to the Endocrinology Outpatient Clinic between 2010 and 2015 for screening of thyroid function were observed till the end of 2019 June and analyzed retrospectively. The children diagnosed with congenital hypothyroidism, acute lymphoblastic leukemia, and seizures and treated with drugs that may have interfered with thyroid function like lithium, antiepileptic, or iodinated drugs and glucocorticoids were excluded from the study.

RESULTS

The data of 77 DS patients were collected, evaluated, and analyzed. The study group consisted of 73 patients (32 girls and 41 boys with the mean age at baseline of 3.0 ± 4.5 years). A total of 63/73 (87%) children were diagnosed with SH. The 16/63 (25.4%) patients were followed-up without the treatment (group SH-T0), and therapy with levothyroxine (L-T4) was introduced in 47/63 (74.6%) SH children with a mean dosage of 1.8 ± 1.0 μg/kg/day (group SH-T1). Thyroxine supplementation did not improve growth expressed as ΔhSDS (0.1 ± 1.3, ranged -2.1 to 3.8 in SH-T0 vs. 0.0 ± 0.7, ranged -1.7 to 1.4 in SH-T1, p = 0.96) and ΔBMI Z-score (0.3 ± 0.9, ranged -0.9 to 2.6 in SH-T0 vs. 0.3 ± 1.1, ranged -2.1 to 2.9 in SH-T1, p = 0.65). Positive anti-TPO and anti-TG antibodies were detected in 7/63 (11.1%) DS cases.

CONCLUSIONS

SH is the most frequent presentation of thyroid gland dysfunction in DS children. A small percentage of patients develop an overt hypothyroidism, particularly in females with mostly positive titer of antithyroid autoantibodies.

High Thyroid-stimulating Hormone Level in Down's Syndrome: A Mere Resetting of Hypothalamopituitary Axis in Subclinical Hypothyroidism?

OBJECTIVE

Hyperthyrotropinemia (HT) or reduced thyroid function in Down syndrome (DS) is not uncommon, causes range from glandular dysgenesis to altered hypothalamopituitary axis. In the present study, we have compared hypothyroid Indian children with and without DS (NDS), especially focusing on family history, goiter, and biochemical features.

METHODS

We conducted this retrospective observational study from previous medical records of children with DS (1-17 years) having an elevated TSH (≥5 mIU/L) who were consecutively referred for with HT to Endocrinology OPD of a tertiary care hospital in India. Records from hypothyroid children (1-17 years) without Down Syndrome (NDS) were evaluated as controls. Free thyroxine (FT4), anti-thyroid peroxidase (TPO) antibody were measured and congenital hypothyroidism was excluded in all subjects.

RESULTS

Thirty-four DS cases [median age 8 years (IQR: 2-14), M: F = 13:21] and 34 controls [median age 10.5 years (IQR: 7-13.25), M: F = 13:21] were comparable in terms of age and sex, Median age of presentation was significantly earlier in case of DS vs NDS [7 years vs. 10 years]. DS children had significantly less family history of thyroid disorders compared to NDS [14.7% vs 64.7%]. Goiter was significantly less common in patients with DS [DS - 32.25% vs. NDS - 73.5%, P = 0.001]. Anti-TPO antibody positivity was significantly less common in patients with DS [DS- 41% vs. NDS- 73.5%, P = 0.014].

CONCLUSION

There is a significant difference in presentation in hypothyroid children with DS compared to NDS. DS children with hypothyroidism compared to NDS, had earlier presentation, lower incidence of traceable family history, goiter, and anti-TPO-antibody positivity.

Evaluation of biochemical and hematological parameters in adults with Down syndrome

Down syndrome (DS) is the most common worldwide cause of intellectual disability of genetic origin and the most common chromosomal disorder affecting live-born infants. In addition to intellectual disability, individuals with DS have other comorbidities and complex medical conditions. The increase in the life expectancy of patients with DS requires expanding the knowledge about their clinical characteristics and related laboratory parameters. Several studies exploring laboratory tests in DS patients exist, but their focus is limited to specific areas of metabolism. Therefore, our main goal was to describe the biochemical and hematological findings in a DS cohort and to compare the values to those of a control population. A total of 248 DS individuals and 84 control subjects were enrolled. DS individuals had a higher frequency of several clinical conditions compared to control individuals and presented with significant differences with respect to the controls in both biochemical and hematological parameters. We found age- and sex-related differences in several of the parameters. A good understanding of the differences in our cohort might be of aid in the clinical follow-up of adults with DS, especially considering that the lifespan of DS individuals may reach 60 years of age in developed countries.

Timing, prevalence, and dynamics of thyroid disorders in children and adolescents affected with Down syndrome

Objectives Limited data on the evolution of thyroid disorders (TD) in Down syndrome (DS) are available. We characterized the timing, prevalence, and dynamics of TD in patients with DS during a long-term follow-up. Methods We retrospectively evaluated 91 children and adolescents with DS (12.5 ± 8.3; follow-up 7.5 ± 6.2). Children were monitored at birth, 6, and 12 months of age and twice a year thereafter. Thyroid status and autoimmunity were periodically investigated. Results TD were detected in 73.6% of patients, in particular congenital hypothyroidism (CH), autoimmune thyroid diseases (ATD) and subclinical hypothyroidism (SH) were recorded in 16.4, 31.8, and 25.3%, respectively. CH was diagnosed at newborn screening in 86.7% of cases and in the first 6 months of life in the remaining 13.3%; the condition was persistent in 61.5% of patients. In more than 30% of CH cases, glandular hypoplasia was also revealed. In the ATD group, 63.1% of patients with Hashimoto's disease (HD, 82.6%) were treated with levothyroxine and subjects with Graves' Disease (GD, 17.4%) started therapy with methimazole. DS with SH were treated in 42.1% of cases. A thyroid hypogenic echopattern, without autoantibody positivity was identified in 27.6% of SH patients. Conclusions The high prevalence and evolution of TD in SD requires frequent monitoring starting in the first months of life. CH can be misdiagnosed at screening. In DS subjects, there is a high prevalence of ATD and non-autoimmune diseases with early antibody-negative phases should not be excluded.

Down Syndrome Is a Metabolic Disease: Altered Insulin Signaling Mediates Peripheral and Brain Dysfunctions

Down syndrome (DS) is the most frequent chromosomal abnormality that causes intellectual disability, resulting from the presence of an extra complete or segment of chromosome 21 (HSA21). In addition, trisomy of HSA21 contributes to altered energy metabolism that appears to be a strong determinant in the development of pathological phenotypes associated with DS. Alterations include, among others, mitochondrial defects, increased oxidative stress levels, impaired glucose, and lipid metabolism, finally resulting in reduced energy production and cellular dysfunctions. These molecular defects seem to account for a high incidence of metabolic disorders, i.e., diabetes and/or obesity, as well as a higher risk of developing Alzheimer’s disease (AD) in DS. A dysregulation of the insulin signaling with reduced downstream pathways represents a common pathophysiological aspect in the development of both peripheral and central alterations leading to diabetes/obesity and AD. This is further strengthened by evidence showing that the molecular mechanisms responsible for such alterations appear to be similar between peripheral organs and brain. Considering that DS subjects are at high risk to develop either peripheral or brain metabolic defects, this review will discuss current knowledge about the link between trisomy of HSA21 and defects of insulin and insulin-related pathways in DS. Drawing the molecular signature underlying these processes in DS is a key challenge to identify novel drug targets and set up new prevention strategies aimed to reduce the impact of metabolic disorders and cognitive decline.

Diminished Blood Pressure Profiles in Children With Down Syndrome

This study sought to analyze blood pressure trends in children with Down syndrome at multiple centers. A multicenter, retrospective, cross-sectional study was performed. All patients were <18 years and had a diagnosis of Down syndrome. Existing comorbidities were nonexclusionary. For each patient, 3 blood pressure recordings were obtained from routine clinic visits. In total, 887 patients with 2661 total blood pressure recordings were included in this study. The average blood pressure percentile for patients was 38.87 with a median percentile of 31.5. Age, sex, and race were not predictive of blood pressure percentile. Compared with established data from the National Heart Lung and Blood Institute and National Health and Nutrition Examination Survey cohort (ages 8-18 years), blood pressure in our Down syndrome population was statistically lower by 6.1 percentile points (P<0.001), with the greatest difference at higher blood pressure percentiles (P<0.001). Only 10% of all Down syndrome cohort blood pressure recordings were greater than the National Heart Lung and Blood Institute/National Health and Nutrition Examination Survey 70th percentile, with no patients meeting criteria for prehypertension or hypertension. Additional comparisons against American Academy of Pediatrics data were similar and statistically significant. In children with Down syndrome, there is a 12 percentile point reduction in baseline blood pressure compared with age- and height-matched controls reported in the National Heart Lung and Blood Institute/National Health and Nutrition Examination Survey and American Academy of Pediatrics cohorts. This data can potentially be utilized in the evaluation and care of persons with Down syndrome in their pediatric medical homes.

Does Tonsillectomy Increase Obesity Risk in Children with Down Syndrome?

OBJECTIVES

To examine weight changes relative to surgical success in children with Down syndrome and obstructive sleep apnea (OSA).

STUDY DESIGN

Retrospective chart review of children with Down syndrome undergoing tonsillectomy from 2005 to 2016 for OSA at a tertiary care children's hospital. Only patients with pre-and postoperative polysomnogram within 6 months of tonsillectomy were included. Demographics, weight, height, and polysomnogram data were collected. Body mass index (BMI), expressed as a percentage of the 95th percentile (%BMI_p95), was calculated for 24 months prior to and following surgery. Pre-and postoperative OSA severity were also recorded. The postoperative obstructive/hypopnea index identified subjects with resolution of obstruction (obstructive/hypopnea index <2 events/hour) or persistent mild/moderate/severe obstructive apnea. Regression analyses were used to compare %BMI_p95 pre- and post-tonsillectomy with %BMI_p95 by OSA status following tonsillectomy.

RESULTS

A total of 78 patients with Down syndrome whose mean age was 5.29 years at time of tonsillectomy were identified. There was no difference between best-fit curves of %BMI _p95 pre-and post-tonsillectomy. There was no difference between best-fit curves of %BMI _p95 in patients who saw resolution of OSA after tonsillectomy vs patients with residual OSA.

CONCLUSIONS

Tonsillectomy neither alters the BMI trajectory of children with Down syndrome, nor changes differentially the risk for obesity in children whose OSA did or did not resolve after surgery.

Thyroid Disorders in Subjects with Down Syndrome: An Update

Down syndrome (DS) is the commonest chromosomal disorder among live born infants. DS is associated with increased risk of endocrine abnormalities particularly thyroid gland disorders. The spectrum of thyroid dysfunction in patients with DS include congenital hypothyroidism, subclinical hypothyroidism, acquired hypothyroidism (autoimmune - non autoimmune), and hyperthyroidism. This review will focus on the characteristics of the different presentations of thyroid abnormalities in DS, screening and management recommendations. (www.actabiomedica.it)

Epidemiological and clinical aspects of autoimmune thyroid diseases in children with Down's syndrome

Aim of this commentary is to report the main peculiarities that have been found to characterize the phenotypic expression of autoimmune thyroid diseases (AITDs) in children with Down's syndrome (DS). According to recent reports, DS children are, per se, more exposed to the risk of both Hashimoto's thyroiditis (HT) and Graves' disease (GD), irrespective of other concomitant risk factors, such as female gender and family antecedents for AITDs. In the context of extra-thyroidal autoimmune disorders, the ones that preferentially aggregate with AITDs in DS children are alopecia areata and vitiligo. Another peculiar aspect, in DS children, is that HT presents with a more severe biochemical picture, which furtherly deteriorates over time. By contrast, GD does not demonstrate a more severe clinical and biochemical picture with respect to that generally observed in patients without DS. Finally, DS children might be at higher risk of progressing from HT toward GD over time.

Increased levels of inflammatory plasma markers and obesity risk in a mouse model of Down syndrome

Down syndrome (DS) is caused by the trisomy of human chromosome 21 and is the most common genetic cause of intellectual disability. In addition to the intellectual deficiencies and physical anomalies, DS individuals present a higher prevalence of obesity and subsequent metabolic disorders than healthy adults. There is increasing evidence from both clinical and experimental studies indicating the association of visceral obesity with a pro-inflammatory status and recent studies have reported that obese people with DS suffer from low-grade systemic inflammation. However, the link between adiposity and inflammation has not been explored in DS. Here we used Ts65Dn mice, a validated DS mouse model, for the study of obesity-related inflammatory markers. Ts65Dn mice presented increased energy intake, and a positive energy balance leading to increased adiposity (fat mass per body weight), but did not show overweight, which only was apparent upon high fat diet induced obesity. Trisomic mice also had fasting hyperglycemia and hypoinsulinemia, and normal incretin levels. Those trisomy-associated changes were accompanied by reduced ghrelin plasma levels and slightly but not significantly increased leptin levels. Upon a glucose load, Ts65Dn mice showed normal increase of incretins accompanied by over-responses of leptin and resistin, while maintaining the hyperglycemic and hypoinsulinemic phenotype. These changes in the adipoinsular axis were accompanied by increased plasma levels of inflammatory biomarkers previously correlated with obesity galectin-3 and HSP72, and reduced IL-6. Taken together, these results suggest that increased adiposity, and pro-inflammatory adipokines leading to low-grade inflammation are important players in the propensity to obesity in DS. We conclude that DS would be a case of impaired metabolic-inflammatory axis.

Subclinical hypothyroidism: A common finding in adult patients with cyanotic congenital heart disease

OBJECTIVE

Cyanotic congenital heart disease is a systemic disease, with effects on multiple organ systems. A high prevalence of subclinical hypothyroidism (SCH) has been reported in a small cohort of cyanotic congenital heart disease patients. Subclinical hypothyroidism has been associated with various adverse cardiovascular effects, as well as an increased risk of progression to overt hypothyroidism. The aim of this study was to examine the prevalence of SCH in cyanotic congenital heart disease patients, consider possible etiologies, and evaluate thyroid function over time.

METHODS

First, 90 clinically stable cyanotic congenital heart disease patients were examined with blood samples (thyroid-stimulating hormone, C-reactive protein, hemoglobin, hematocrit, and N-terminal pro-brain-natriuretic peptide) in a cross-sectional descriptive study. Second, a longitudinal follow-up study of 43 patients originating from the first study part, was carried out. These patients had thyroid function parameters (thyroid-stimulating hormone, thyroid hormones, and thyroid peroxidase antibodies) evaluated biannually.

RESULTS

Elevated thyroid-stimulating hormone was present in 24% of the 90 screened patients. During follow-up (6.5 ± 1.0 years), SCH (defined as ≥2 consecutive elevated thyroid-stimulating hormone values) was present in 26%. Three patients progressed to overt hypothyroidism. Patients with SCH were younger (34 ± 12 vs 42 ± 16 years; P = .01) and had a lower oxygen saturation (80 ± 5 vs 84 ± 6%; P = .03).

CONCLUSION

Subclinical hypothyroidism is a very common finding in cyanotic congenital heart disease. This is not associated with increased levels of C-reactive protein, heart failure, or autoimmunity but appears to be associated with cyanosis and age. Since the clinical impact of SCH is uncertain, further studies are needed to determine this. Regular thyroid evaluation is recommended in cyanotic congenital heart disease patients since SCH can develop to overt hypothyroidism.

Challenges in measuring the effects of pharmacological interventions on cognitive and adaptive functioning in individuals with Down syndrome: A systematic review

We systematically reviewed the measures used in pharmaceutical trials in children/adults with Down syndrome without dementia. Our purpose was to identify developmentally appropriate outcome measures capable of detecting changes in cognitive and adaptive functioning in this population. Eleven studies were included and used diverse outcome measures across the domains of language, memory, attention, behavior, and executive/adaptive functioning. Our results highlight the challenges in selecting measures capable of capturing improvements in pharmaceutical trials in individuals with DS. We offer suggestions to enhance future research, including: conducting studies with larger samples of participants with a range of developmental abilities; modifying existing/developing novel outcome measures; incorporating advances from related areas and DS observational studies; and considering alternative analytic techniques to characterize treatment effects.

Evaluation of uric acid levels, thyroid function, and anthropometric parameters in Japanese children with Down syndrome

Down syndrome, caused by trisomy 21, is characterized by congenital abnormalities as well as mental retardation. From the neonatal stage through adolescence, patients with Down syndrome often have several complications. Thus, it is important to attain knowledge of the prevalence of these comorbidities in children with Down syndrome. We, therefore, evaluated the biochemical data, thyroid function, and anthropometric parameters, and analyzed the association among them in Japanese children and early adolescents with Down syndrome. There was no difference in the prevalence of obesity and overweight between boys and girls. The level of uric acid was higher in boys than in girls. Moreover, the prevalence of hyperuricemia was also higher in boys than in girls (approximately 32% and 10%, respectively). The prevalence of subclinical hypothyroidism in children with Down syndrome was approximately 20%, with no significant sex differences. The levels of uric acid and dehydroepiandrosterone-sulfate were positively associated with age, while the levels of thyroid-stimulating hormone and free thyroxine had a negative association with age. Overall, children with Down syndrome, exhibit a higher incidence of hyperuricemia. Therefore, uric acid levels, as well as thyroid function, from childhood to early adulthood should be monitored in this patient cohort.

The burden of trisomy 21 disrupts the proteostasis network in Down syndrome

Down syndrome (DS) is a genetic disorder caused by trisomy of chromosome 21. Abnormalities in chromosome number have the potential to lead to disruption of the proteostasis network (PN) and accumulation of misfolded proteins. DS individuals suffer from several comorbidities, and we hypothesized that disruption of proteostasis could contribute to the observed pathology and decreased cell viability in DS. Our results confirm the presence of a disrupted PN in DS, as several of its elements, including the unfolded protein response, chaperone system, and proteasomal degradation exhibited significant alterations compared to euploid controls in both cell and mouse models. Additionally, when cell models were treated with compounds that promote disrupted proteostasis, we observed diminished levels of cell viability in DS compared to controls. Collectively our findings provide a cellular-level characterization of PN dysfunction in DS and an improved understanding of the potential pathogenic mechanisms contributing to disrupted cellular physiology in DS. Lastly, this study highlights the future potential of designing therapeutic strategies that mitigate protein quality control dysfunction.

Thyroid dysfunction in patients with Down syndrome: Results from a multi-institutional registry study

The goals of this undertaking were to assess the outcomes of thyroid screening tests and adherence to thyroid screening guidelines across five Down syndrome (DS) specialty clinics in various states. Data related to thyroid screening were collected for 663 individuals across five clinics specializing in the comprehensive care of individuals with DS for a period of 1 year. Of the 663 participants, 47.7% of participants had a TSH and free T4 ordered at their DS specialty clinic visit. Approximately 19.0% (60/316) had a new thyroid disorder diagnosis made. We conclude that a sizable proportion of the patients with DS are not up-to-date on current guidelines when they present to a DS specialty clinic, while adherence to thyroid screening guidelines helps facilitate early diagnoses. Hypothyroidism is prevalent in the population, consistent with reported literature. DS specialty clinics can help patients stay current on screening guidelines.

Role of astrocyte-synapse interactions in CNS disorders

Astrocytes comprise half of the cells in the brain. Although astrocytes have traditionally been described as playing a supportive role for neurons, they have recently been recognized as active participants in the development and plasticity of dendritic spines and synapses. Astrocytes can eliminate dendritic spines, induce synapse formation, and regulate neurotransmission and plasticity. Dendritic spine and synapse impairments are features of many neurological disorders, including autism spectrum disorder, schizophrenia, and Alzheimer's disease. In this review we will present evidence from multiple neurological disorders demonstrating that changes in astrocyte-synapse interaction contribute to the pathologies. Genomic analysis has connected altered astrocytic gene expression with synaptic deficits in a number of neurological disorders. Alterations in astrocyte-secreted factors have been implicated in the neuronal morphology and synaptic changes seen in neurodevelopmental disorders, while alteration in astrocytic glutamate uptake is a core feature of multiple neurodegenerative disorders. This evidence clearly demonstrates that maintaining astrocyte-synapse interaction is crucial for normal central nervous system functioning. Obtaining a better understanding of the role of astrocytes at synapses in health and disease will provide a new avenue for future therapeutic targeting.

Analysis of the factors affecting the evolution over time of subclinical hypothyroidism in children

Aim of this commentary is to report the most recent views about natural history of subclinical hypothyroidism (SH) according to the different etiologies. In children with idiopathic SH the natural evolution is often favourable, with a high percentage of cases reverting to euthyroidism or remaining SH even after a prolonged follow-up. By contrast, the risk of a significant deterioration of thyroid status is distinctly higher in the SH children with Hashimoto’s thyroiditis (HT). This risk is even higher in the cases with both HT-related SH and chromosomal abnormalities, such as Turner or Down’s syndrome.

In children with autoimmune thyroid diseases the association with Down syndrome can modify the clustering of extra-thyroidal autoimmune disorders

BACKGROUND

It is known that the association with Down syndrome (DS) can affect the phenotypic expression of autoimmune thyroid diseases (AITDs), whilst is unknown whether the clustering of extra-thyroidal autoimmune diseases (ETADs) may also be atypical in DS children.

METHODS

The aim of this study was to investigate the clustering of ETADs in 832 children with AITDs divided in two groups with or without DS (A and B, respectively) and in four subgroups of patients aged either <6 or ≥6 years.

RESULTS

The rate of children with ETADs was significantly higher in Group A; in particular, alopecia areata (p=0.00001) and vitiligo (p=0.00001) were found more often in Group A irrespective of age, whilst the distribution of T1 diabetes mellitus was not different in the two groups. Celiac disease prevalence was significantly higher in DS patients only in the older subgroup.

CONCLUSIONS

The association with DS may be able to modify the clustering of ETADs in the children with AITDs by favoring the aggregation of some specific diseases such as alopecia areata and vitiligo.

[Congenital hypothyroidism]

Congenital hypothyroidism (CH) is a cause of preventable mental retardation; therefore, timely diagnosis and treatment by the primary care physician is very important. CH screening must be performed between the second and fifth days of life with capillary blood done with a heel prick and must be confirmed by measurement of thyroid hormones in venous blood. The most common cause of CH is thyroid dysgenesis, which may be identified by a thyroid scan carried out before initiating treatment. Treatment should be with levothyroxine (10-15μg/kg/day) and should not be delayed or suspended during the first 3 years of life due to the deleterious effect on neurodevelopment in case of low thyroid hormones during this time. Preterm or sick infants or those with Down syndrome require special consideration. This article provides diagnostic and therapeutic algorithms for CH.

Assessing cognitive improvement in people with Down syndrome: important considerations for drug-efficacy trials

Experimental research over just the past decade has raised the possibility that learning deficits connected to Down syndrome (DS) might be effectively managed by medication. In the current chapter, we touch on some of the work that paved the way for these advances and discuss the challenges associated with translating them. In particular, we highlight sources of phenotypic variability in the DS population that are likely to impact performance assessments. Throughout, suggestions are made on how to detect meaningful changes in cognitive-adaptive function in people with DS during drug treatment. The importance of within-subjects evaluation is emphasized.

Stem and progenitor cell dysfunction in human trisomies

Trisomy 21, the commonest constitutional aneuploidy in humans, causes profound perturbation of stem and progenitor cell growth, which is both cell context dependent and developmental stage specific and mediated by complex genetic mechanisms beyond increased Hsa21 gene dosage. While proliferation of fetal hematopoietic and testicular stem/progenitors is increased and may underlie increased susceptibility to childhood leukemia and testicular cancer, fetal stem/progenitor proliferation in other tissues is markedly impaired leading to the characteristic craniofacial, neurocognitive and cardiac features in individuals with Down syndrome. After birth, trisomy 21-mediated premature aging of stem/progenitor cells may contribute to the progressive multi-system deterioration, including development of Alzheimer's disease.

Multimorbidity in older adults with intellectual disabilities

Multimorbidity may be related to the supposed early aging of people with intellectual disabilities (ID). This group may suffer more often from multimorbidity, because of ID-related physical health conditions, unhealthy lifestyle and metabolic effects of antipsychotic drug use. Multimorbidity has been defined as two or more chronic conditions. Data on chronic conditions have been collected through physical assessment, questionnaires, and medical files. Prevalence, associated factors and clusters of multimorbidity have been studied in 1047 older adults (≥ 50 years) with ID. Multimorbidity was prevalent in 79.8% and associated with age and severe/profound ID. Four or more conditions were prevalent in 46.8% and associated with age, severe/profound ID and Down syndrome. Factor analyses did not reveal a model for disease-clusters with good fit. Multimorbidity is highly prevalent in older adults with ID. Multimorbidity should receive more attention in research and clinical practice for targeted pro-active prevention and treatment.