Ten-year longitudinal study of thyroid function in children with Down's syndrome

Severe myxedema coma and pericardial effusion in a child with Down syndrome: the importance of adherence to levothyroxine therapy

BACKGROUND

Myxedema coma is a rare, but life-threatening endocrinological emergency. Myxedema is characterized by altered mental status, and is accompanied by hypotension, bradycardia, hypothermia, bradypnea, hyporeflexia, hyponatremia, and hypoglycemia, all stemming from reduced metabolism due to severe hypothyroidism. Additionally, patients may exhibit signs of low cardiac output, edema in the extremities, peripheral circulatory disturbances, shock, and the development of pericardial and pleural effusions, ultimately leading to confusion and coma. We present a successfully treated case of severe myxedema coma with recurrent pericardial effusion and hypotensive shock. This case is characterized by an unusual clinical presentation and required a distinct treatment strategy highlighting its exceptional rarity.

CASE

A 2-year-old boy with Down syndrome presented with recurrent pericardial effusion attributed to medication non-adherence. The critically-ill patient, experiencing a severe cardiogenic shock required mechanical ventilation and inotropic infusions in the pediatric intensive care unit. Elevated thyroid stimulating hormone (TSH), and low free T4 (fT4) and free T3 (fT3) levels prompted consideration of myxedema coma. Upon reviewing the patient's medical history, it was ascertained that he had an ongoing diagnosis of primary hypothyroidism, and exhibited non-adherence to the prescribed treatment regimen and failed to attend scheduled outpatient clinic appointments for follow-up assessments. The treatment plan, devised by the pediatric endocrinology team, included the peroral administration of L-thyroxine (L-T4) at a dose of 50 micrograms per day. After beginning regular oral L-T4 treatment, a gradual improvement in the patient's condition was observed. Notably, by the 15th day of oral therapy, the patient had made a full recovery. Contrary to the recommended intravenous treatment for myxedema coma, this patient was successfully treated with oral levothyroxine, due to the unavailability of the parenteral form in Türkiye.

CONCLUSIONS

This case report presents an instance of non-adherence to L-T4 therapy, which subsequently progressed to severe myxedema coma. Changes in neurologic status and hemodynamic instability in a patient with a history of hypothyroidism should raise the concern of nonadherence and, though rare, myxedema coma should be in the differential diagnosis.

JAK inhibition decreases the autoimmune burden in Down syndrome

Individuals with Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), display clear signs of immune dysregulation, including high rates of autoimmune disorders and severe complications from infections. Although it is well established that T21 causes increased interferon responses and JAK/STAT signaling, elevated autoantibodies, global immune remodeling, and hypercytokinemia, the interplay between these processes, the clinical manifestations of DS, and potential therapeutic interventions remain ill defined. Here, we report a comprehensive analysis of immune dysregulation at the clinical, cellular, and molecular level in hundreds of individuals with DS. We demonstrate multi-organ autoimmunity of pediatric onset concurrent with unexpected autoantibody-phenotype associations. Importantly, constitutive immune remodeling and hypercytokinemia occur from an early age prior to autoimmune diagnoses or autoantibody production. We then report the interim analysis of a Phase II clinical trial investigating the safety and efficacy of the JAK inhibitor tofacitinib through multiple clinical and molecular endpoints. Analysis of the first 10 participants to complete the 16-week study shows a good safety profile and no serious adverse events. Treatment reduced skin pathology in alopecia areata, psoriasis, and atopic dermatitis, while decreasing interferon scores, cytokine scores, and levels of pathogenic autoantibodies without overt immune suppression. Additional research is needed to define the effects of JAK inhibition on the broader developmental and clinical hallmarks of DS. ClinicalTrials.gov identifier: NCT04246372.

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.

Clinical practice - latest insights in optimizing the care of children with Down syndrome

An essential part of the care of children with Down syndrome is secondary screening for comorbidity. It is well known that comorbidity frequently occurs in these children. A new update of the Dutch Down syndrome medical guideline was developed to create a sound evidence base for several of these conditions. We present the latest insights and recommendations from this Dutch medical guideline which are based on the most relevant literature currently available and developed with rigorous methodology. The main focus of this revision of the guideline was on obstructive sleep apnea and other airway problems and hematologic disorders, such as transient abnormal myelopoiesis, leukemia, and thyroid disorders. Conclusion: This is a short summary of the latest insights and recommendations from the updated Dutch medical guideline for children with Down syndrome.

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.

Congenital Hypothyroidism: Screening and Management

ABSTRACT

Untreated congenital hypothyroidism (CH) leads to intellectual disabilities. Prompt diagnosis by newborn screening (NBS) leading to early and adequate treatment results in grossly normal neurocognitive outcomes in adulthood. However, NBS for hypothyroidism is not yet established in all countries globally. Seventy percent of neonates worldwide do not undergo NBS.The initial treatment of CH is levothyroxine, 10 to 15 mcg/kg daily. The goals of treatment are to maintain consistent euthyroidism with normal thyroid-stimulating hormone and free thyroxine in the upper half of the age-specific reference range during the first 3 years of life. Controversy remains regarding detection of thyroid dysfunction and optimal management of special populations, including preterm or low-birth weight infants and infants with transient or mild CH, trisomy 21, or central hypothyroidism.Newborn screening alone is not sufficient to prevent adverse outcomes from CH in a pediatric population. In addition to NBS, the management of CH requires timely confirmation of the diagnosis, accurate interpretation of thyroid function testing, effective treatment, and consistent follow-up. Physicians need to consider hypothyroidism in the face of clinical symptoms, even if NBS thyroid test results are normal. When clinical symptoms and signs of hypothyroidism are present (such as large posterior fontanelle, large tongue, umbilical hernia, prolonged jaundice, constipation, lethargy, and/or hypothermia), measurement of serum thyroid-stimulating hormone and free thyroxine is indicated, regardless of NBS results.

Identifying metabolic parameters related to severity and extent of periodontitis in down syndrome patients

BACKGROUND AND OBJECTIVE

Systemic metabolic status and periodontitis can be related in patients with Down syndrome (DS). The objective of this study was to identify metabolic indicators (anthropometric measurements, blood pressure, and serum markers) related to severity and extent of periodontitis in DS patients.

METHODS

A cross-sectional study was conducted with 49 patients with DS. Periodontal evaluation included the periodontal probing depth (PPD), clinical attachment level (CAL), gingival bleeding index (GBI), and visible plaque index (VPI). Periodontitis severity was classified by the stages system. The extent of periodontitis was assessed as the percentage of sites with CAL ≥3 mm, CAL ≥4 mm, PPD ≥4 mm, and PPD ≥5 mm. The metabolic condition of the participants was determined by analyzing anthropometric parameters, blood pressure, and serum markers. Data were analyzed using the Mann-Whitney test, Spearman's correlation coefficient, and multivariate regression analysis.

RESULTS

Periodontitis stage 3/4 was detected in 32.7% of patients, with high values of VPI (54.6 ± 35.8) and GBI (42.4 ± 33.3). The severity of periodontitis was related to higher mean corpuscular hemoglobin (β = .291, p = .028) and mean corpuscular volume values (β = .293, p = .046). Arm circumference measurements were inversely related to CAL ≥3 mm (β = -.408, p = .023), PPD ≥4 mm (β = -.475, p = .006), and PPD ≥5 mm (β = -.443, p = .010).

CONCLUSIONS

The findings suggest that the severity and extent of periodontitis may be related to some metabolic parameters in DS patients.

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.

Physical Growth and Its Determinants in Indian Children with Down Syndrome, from 3 Months to 5 Years of Age

OBJECTIVE

To compare the growth of Indian children with Down syndrome (DS), with typically developing Indian children. The effect of comorbidities on their physical growth was also evaluated, so that factors affecting growth can be identified early and timely interventions be planned.

METHODS

A cross-sectional study was conducted at the All India Institute of Medical Sciences, New Delhi from June 2015 to June 2017. Children with karyotype-proven DS within age group of 3 mo to 5 y were enrolled as study subjects. Children with DS having mosaic karyotype were excluded. Anthropometry and associated comorbidities were assessed.

RESULTS

Hundred and eight children with DS were enrolled, mean WHO z scores were-WAZ: -2.31 (SD 1.44), HAZ: -2.51 (SD 1.47), BAZ: -1.07 (SD 1.8), and HCZ: -2.79 (SD 1.21). Congenital heart disease (in 44.5% children), hypothyroidism (in 27.7%), and anemia (in 50%) were the common comorbidities. Growth parameters of children with and without any comorbidity were significantly different, mean WHO z scores were WAZ -2.61 vs. -1.09 (p = 0.005), HAZ -2.43 vs. -2.41 (p = 0.3), BAZ -1.49 vs. -0.38 (p = 0.001), and HCZ -3.13 vs. -2.33 (p = 0.001).

CONCLUSION

Growth of Indian children with DS is significantly less compared to normally growing children. Weight was affected maximum during infancy, length was more affected as the age progressed, head circumference was affected similarly in all age groups, whereas BMI showed almost progressive increase with age. Children with severe heart disease had significantly lower BMI whereas children with treated hypothyroidism had better growth. There is a need for a large longitudinal study on Indian children with DS to construct Indian DS-specific growth charts.

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.

Post-infectious inflammatory syndrome associated with SARS-CoV-2 in a paediatric patient with Down syndrome

Neurological complications of SARS-CoV-2 continue to be recognised. In children, neurological phenomenon has been reported generally in the acute infectious period. It is possible that SARS-CoV-2 could trigger an immune-mediated post-infectious phenomenon. Here, we present a unique case of post-infectious marantic cardiac lesion causing cerebrovascular accident in a patient with Down syndrome.

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.

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 and COVID-19: A Perfect Storm?

People with Down syndrome show signs of chronic immune dysregulation, including a higher prevalence of autoimmune disorders, increased rates of hospitalization during respiratory viral infections, and higher mortality rates from pneumonia and sepsis. At the molecular and cellular levels, they show markers of chronic autoinflammation, including interferon hyperactivity, elevated levels of many inflammatory cytokines and chemokines, and changes in diverse immune cell types reminiscent of inflammatory conditions observed in the general population. However, the impact of this immune dysregulation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and CoV disease of 2019 (COVID-19) remains unknown. This Perspective outlines why individuals with Down syndrome should be considered an at-risk population for severe COVID-19. Specifically, the immune dysregulation caused by trisomy 21 may result in an exacerbated cytokine release syndrome relative to that observed in the euploid population, thus justifying additional monitoring and specialized care for this vulnerable population.

Thyroid disorders in Taiwanese children with Down syndrome: The experience of a single medical center

BACKGROUND/PURPOSE

Thyroid disorders are common in children with Down syndrome (DS), however, such data have rarely been reported in Taiwanese children. This study presents our experience with the management of these children.

METHODS

Between 2006 and 2016, 51 children (31 boys and 20 girls) with DS were enrolled. Thyroid function was evaluated and natural course of thyroid status were analyzed.

RESULTS

Of 51 patients with DS, 2 had congenital hypothyroidism due to dyshormonogenesis. Of the remaining 49 patients, 30 (61%) had euthyroidism (EuT), and 19 (39%) had subclinical hypothyroidism (SH). Eighteen (37%) had detectable thyroid antibodies. It occurred at any age and the incidence was not affected by sex. The mean follow-up duration for 39 DS children was 3.8 ± 2.4 years. Of the 26 children who had EuT at enrollment and were followed up, 22 remained EuT, 2 developed SH, 1 developed overt hypothyroidism, and 1 developed overt hyperthyroidism. Of the 13 patients with SH who were followed up, 1 was treated for high thyroid-stimulating hormone levels, 8 became EuT, and 4 maintained SH status. Children with DS and persistent SH had significantly higher maximum thyroid-stimulating hormone levels during follow-up than did those with transient SH. Fluctuation in thyroid status during follow-up was not uncommon in children with DS.

CONCLUSION

The prevalence of thyroid disorders is higher in Taiwanese children with DS than in the general population. Because symptoms of hypothyroidism overlap those inherent to DS, regular follow-up of thyroid function in children with DS is indicated.

Trisomy 21 activates the kynurenine pathway via increased dosage of interferon receptors

Trisomy 21 (T21) causes Down syndrome (DS), affecting immune and neurological function by ill-defined mechanisms. Here we report a large metabolomics study of plasma and cerebrospinal fluid, showing in independent cohorts that people with DS produce elevated levels of kynurenine and quinolinic acid, two tryptophan catabolites with potent immunosuppressive and neurotoxic properties, respectively. Immune cells of people with DS overexpress IDO1, the rate-limiting enzyme in the kynurenine pathway (KP) and a known interferon (IFN)-stimulated gene. Furthermore, the levels of IFN-inducible cytokines positively correlate with KP dysregulation. Using metabolic tracing assays, we show that overexpression of IFN receptors encoded on chromosome 21 contribute to enhanced IFN stimulation, thereby causing IDO1 overexpression and kynurenine overproduction in cells with T21. Finally, a mouse model of DS carrying triplication of IFN receptors exhibits KP dysregulation. Together, our results reveal a mechanism by which T21 could drive immunosuppression and neurotoxicity in DS.

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.

Down syndrome with primary thyroid diffuse large B-cell lymphoma and Hashimoto thyroiditis: A CARE compliant case report

RATIONALE

Adult patients with Down syndrome (DS) commonly develop Hashimoto thyroiditis (HT). However, primary diffuse large B-cell lymphoma (DLBCL) of the thyroid is uncommon, and its simultaneous occurrence with HT is very rare. To our knowledge, coexisting DLBCL and HT in a patient with DS has not been reported in the medical literature.

PATIENT CONCERNS

We present a 43-year-old woman with DS who reported progressive swelling of the neck on the right side and dyspnea over the previous 1 month, with associated neck ache, hoarseness, and dysphagia. Thyroid ultrasonography and computed tomography of the neck revealed a large mass in the right lobe compressing the surrounding tissues.

DIAGNOSES

Based on the clinical and histopathologic findings, the patient was diagnosed with coexisting primary thyroid DLBCL and HT.

INTERVENTIONS

A palliative unilateral thyroidectomy was performed; postoperative histopathology and immunohistochemistry revealed thyroid DLBCL and HT. The patient was scheduled for chemotherapy and targeted therapy after recovering from surgery.

OUTCOMES

The patient died 3 weeks after surgery due to asphyxia caused by uncontrollable growth of recurrent tumor.

LESSONS

The coexistence of DS, primary thyroid DLBCL, and HT is very rare. There is no standardized approach to the clinical identification of primary thyroid lymphoma (PTL), making early diagnosis difficult. A multidisciplinary approach and close follow-up are needed. The mechanisms of the link between DS and PTL are poorly understood and remain to be elucidated.

Dementia in Down syndrome: unique insights for Alzheimer disease research

Virtually all adults with Down syndrome (DS) show the neuropathological changes of Alzheimer disease (AD) by the age of 40 years. This association is partially due to overexpression of amyloid precursor protein, encoded by APP, as a result of the location of this gene on chromosome 21. Amyloid-β accumulates in the brain across the lifespan of people with DS, which provides a unique opportunity to understand the temporal progression of AD and the epigenetic factors that contribute to the age of dementia onset. This age dependency in the development of AD in DS can inform research into the presentation of AD in the general population, in whom a longitudinal perspective of the disease is not often available. Comparison of the risk profiles, biomarker profiles and genetic profiles of adults with DS with those of individuals with AD in the general population can help to determine common and distinct pathways as well as mechanisms underlying increased risk of dementia. This Review evaluates the similarities and differences between the pathological cascades and genetics underpinning DS and AD with the aim of providing a platform for common exploration of these disorders.

Endocrine and metabolic complications in children and adolescents with Sickle Cell Disease: an Italian cohort study

BACKGROUND

Children with Sickle Cell Disease (SCD) show endocrine complications and metabolic alterations. The physiopathology of these conditions is not completely understood: iron overload due to chronic transfusions, ischemic damage, and inflammatory state related to vaso-occlusive crises may be involved. Aims of this study were to evaluate the growth pattern, endocrine complications, and metabolic alterations and to detect the relationship between these conditions and the SCD severity in affected children and adolescents.

METHODS

Fifty-two children and adolescents with SCD [38 homozygous sickle hemoglobin (HbSS) and 14 heterozygous sickle hemoglobin (HbSC); age range 3-18 years] were recruited. Anthropometric [height, body mass index (BMI), arm span, sitting height, target height (TH), and pubertal status] and laboratory [blood cell counts, hemolysis indices, metabolic and nutritional status indices and hormonal blood levels] data were evaluated. The SCD severity was defined according to hematological and clinical parameters.

RESULTS

Height-SDS adjusted for TH and BMI-SDS were significantly higher in HbSC children than in HbSS ones. Forty-eight out of 52 patients (92%) had at least one metabolic and/or endocrine alteration: insufficiency/deficiency of vitamin D (84.7%), insulin resistance (11.5%), growth hormone deficiency (3.8%), subclinical hypothyroidism (3.8%), and hypogonadism (1.9%). Levels of vitamin D were significantly and negatively correlated with clinical indicators of the SCD severity. Subjects with HbSS genotype show significant lower levels of both insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein 3 than children with HbSC. In the study population IGF-1 values were significantly and positively correlated with Hb and negatively with lactate dehydrogenase.

CONCLUSIONS

Metabolic alterations and endocrine complications are very common in children and adolescents with SCD. A regular follow-up is necessary to identify subjects at risk for complications to precociously start an appropriate treatment and to improve the quality of life of SCD patients.

[Genetics, diagnosis and characteristics of trisomy 21]

Trisomy 21 remains relevant today. As patients' life expectancy increases, medical monitoring shows the importance of screening for associated complications such as epilepsy and sleep apnoea. For caregivers, it constitutes a care model for intellectually disabled people notably with regard to anxiety, poor expression of pain and family suffering. Scientific advances raise hope of progress in therapeutic practices.

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)

Pattern of Thyroid Disorders in Children and Adolescents Seen at the Lagos University Teaching Hospital, Nigeria, Over a 10-year Period

Introduction:

Thyroid disorders account for a large proportion of pediatric endocrine disorders. Untreated hypothyroidism in childhood has permanent adverse effects on physical, intellectual, and neurological development. However, few studies have reported the pattern of pediatric thyroid disorders in Nigeria.

Objectives:

The objective of this study was to document the pattern of thyroid disorders in children and adolescents seen at the Lagos University Teaching Hospital (LUTH) over a 10-year period.

Participants and Methods:

This is a retrospective descriptive study involving children with thyroid disorders seen from January 1, 2006 to December 31, 2015.

Results:

Seventy-one patients with thyroid disorders (0.13%) were seen out of 52,800 new cases (incidence of 1/1000 new cases) comprising 13.4% of 546 pediatric endocrine cases with a male:female ratio of 1:1.2. Median (range) age at presentation was 1.6 (0.001–14) years. Congenital hypothyroidism (CH) constituted a major proportion of cases (46.7%), with a median (range) age at presentation of 9 (1.5–24) months. Down syndrome constituted 45% of patients with CH with associated congenital heart defects in eight (53%) patients. Acquired hypothyroidism was seen in ten patients (five goitrous and five nongoitrous). Six patients had hypothyroidism associated with multiple anterior pituitary hormone deficiency. Nine patients (all females) had hyperthyroidism with confirmed Graves' disease in 5 (55.6%), with mean age at presentation being 9.4 ± 2.09 years. Other conditions were euthyroid sick syndrome (2.8%), euthyroid goiter (1.4%), and acute thyroiditis (1.4%). Eight infants of mothers on treatment for hyperthyroidism ( first seen between the 7^th h of life to 2 months of age) had transient hypothyroidism while one 8-day-old had transient hyperthyroidism.

Conclusion:

CH was the most common disorder encountered with late age at presentation. Routine newborn screening and maintaining a high index of suspicion are advocated.

Early thyroxine treatment in Down syndrome and thyroid function later in life

OBJECTIVE

The hypothalamus-pituitary-thyroid (HPT) axis set point develops during the fetal period and first two years of life. We hypothesized that thyroxine treatment during these first two years, in the context of a randomized controlled trial (RCT) in children with Down syndrome, may have influenced the HPT axis set point and may also have influenced the development of Down syndrome-associated autoimmune thyroiditis.

METHODS

We included 123 children with Down syndrome 8.7 years after the end of an RCT comparing thyroxine treatment vs placebo and performed thyroid function tests and thyroid ultrasound. We analyzed TSH and FT4 concentrations in the subgroup of 71 children who were currently not on thyroid medication and had no evidence of autoimmune thyroiditis.

RESULTS

TSH concentrations did not differ, but FT4 was significantly higher in the thyroxine-treated group than that in the placebo group (14.1 vs 13.0 pmol/L; P = 0.02). There was an increase in anti-TPO positivity, from 1% at age 12 months to 6% at age 24 months and 25% at age 10.7 years with a greater percentage of children with anti-TPO positivity in the placebo group (32%) compared with the thyroxine-treated group (18.5%) (P = 0.12). Thyroid volume at age 10.7 years (mean: 3.4 mL; range: 0.5-7.5 mL) was significantly lower (P < 0.01) compared with reference values (5.5 mL; range: 3-9 mL) and was similar in the thyroxine and placebo group.

CONCLUSION

Thyroxine treatment during the first two years of life led to a mild increase in FT4 almost 9 years later on and may point to an interesting new mechanism influencing the maturing HPT axis set point. Furthermore, there was a trend toward less development of thyroid autoimmunity in the thyroxine treatment group, suggesting a protective effect of the early thyroxine treatment. Lastly, thyroid volume was low possibly reflecting Down-specific thyroid hypoplasia.

Characterization of Thyroid Abnormalities in a Large Cohort of Children with Down Syndrome

BACKGROUND/AIMS

Thyroid disease is a common comorbidity in individuals with Down syndrome (DS), but historical studies have multiple limitations. We assessed thyroid abnormalities in a large cohort of children with DS.

METHODS

Retrospective records review from a single institution. Calculated prevalence of common thyroid abnormalities and associations with common comorbidities.

RESULTS

Among 508 patients, 120 (24%) had a thyroid-related diagnosis, the majority having elevated thyrotropin treated with levothyroxine. A Kaplan-Meier estimate projects that 50% have thyroid disorder by adulthood, with 20% of hypothyroidism diagnosed before the age of 6 months. When tested, approximately 50% had positive antithyroid antibodies, though this rate was 100% in overt hypothyroidism. There was no association between congenital or acquired hypothyroidism and common comorbidities.

CONCLUSION

Thyroid disease in DS is more common and occurs earlier than in the general population, and is often transient. Thyroid disease is unrelated to gender, obesity, or other comorbidities. Apart from overt hypothyroidism, much of hypothyroidism in DS appears unrelated to autoimmunity; we recommend checking of antithyroid antibodies only in select cases. An additional screen for thyroid disease between the newborn screen and the 6-month well-child visit will detect early cases of hypothyroidism who passed their newborn screen.
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Down syndrome-A narrative review with a focus on anatomical features

Down syndrome (DS) is the most common aneuploidy of chromosome 21, characterized by the presence of an extra copy of that chromosome (trisomy 21). Children with DS present with an abnormal phenotype, which is attributed to a loss of genetic balance or an excess dose of chromosome 21 genes. In recent years, advances in prenatal screening and diagnostic tests have aided in the early diagnosis and appropriate management of fetuses with DS. A myriad of clinical symptoms resulting from cognitive, physical, and physiological impairments caused by aberrations in various systems of the body occur in DS. However, despite these impairments, which range from trivial to fatal manifestations, the survival rate of individuals with DS has increased dramatically from less than 50% during the mid-1990s to 95% in the early 2000s, with a median life expectancy of 60 years reported recently. The aim of this narrative review is to review and summarize the etiopathology, prenatal screening and diagnostic tests, prognosis, clinical manifestations in various body systems, and comorbidities associated with DS. Clin. Anat. 29:568-577, 2016. © 2015 Wiley Periodicals, Inc.

Thyroid function in Down syndrome

Down syndrome is the most commonly encountered human chromosomal disorder. Down syndrome is associated with thyroid dysfunction including: hypothyroidism, both congenital and acquired, and hyperthyroidism. A genetic predisposition and a propensity to acquire autoimmune disorders seem to be possible factors, though their causal relation remains unclear. The aim of the review is to describe what is currently known about the association between Down syndrome and thyroid dysfunction.