Morbidity and medication in a large population of individuals with Down syndrome compared to the general population

Measurement protocols and determinants of peak oxygen consumption in adults with Down syndrome: a systematic review

This systematic review aimed to provide an overview of test protocols used to measure peak oxygen uptake (VO2peak) in adults with Down syndrome (DS) and to determine how generalisable the outcomes are for the entire population of adults with DS by describing the sample characteristics of these studies and their impact on VO2peak. A literature search (PROSPERO CRD42022309560) was performed (18 July 2023) using the following databases: PubMed, CINAHL, APA PsycINFO, Web of Science, Embase and SPORTDiscus. For articles to be included, they had to be peer-reviewed pubications, reporting VO2peak or VO2max for individuals with DS separately, with a sample of n ≥ 5 and a mean age ≥18 years. Systematic reviews and meta-analyses were excluded but their reference lists were searched for additional papers to include. Studies were evaluated for risk of bias following the guidelines of Kmet et al. The results were summarised with frequency statistics. Forty-three studies were included in this systematic review. Sample sizes of included adults with DS ranged from n = 4-226, with a total of n = 1498 adults with DS being included. Most studies (29/43) used the same standardised maximal exercise treadmill protocol to measure VO2peak in adults with DS, and 33 out of 43 studies used at least one objective criterion to determine a valid maximal effort. Participants were predominantly male, under 40 years old, and overweight or obese. Additionally, the diversity of study samples was lacking or not reported. The most widely used, standardised, maximal exercise test treadmill protocol is recommended for future use in research and practice, including objective criteria to determine valid maximal effort. The current study samples are not representative of the population of adults with DS in terms of sex, age and diverse backgrounds and therefore likely overestimate VO2peak of this population.

A clinical-translational review of sleep problems in neurodevelopmental disabilities

Sleep disorders are very common across neurodevelopmental disorders and place a large burden on affected children, adolescents, and their families. Sleep disturbances seem to involve a complex interplay of genetic, neurobiological, and medical/environmental factors in neurodevelopmental disorders. In this review, we discuss animal models of sleep problems and characterize their presence in two single gene disorders, Rett Syndrome, and Angelman Syndrome and two more commonly occurring neurodevelopmental disorders, Down Syndrome, and autism spectrum disorders. We then discuss strategies for novel methods of assessment using wearable sensors more broadly for neurodevelopmental disorders in general, including the importance of analytical validation. An increased understanding of the mechanistic contributions and potential biomarkers of disordered sleep may offer quantifiable targets for interventions that improve overall quality of life for affected individuals and their families.

A pathway linking pulse pressure to dementia in adults with Down syndrome

Adults with Down syndrome are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease and is linked to a diagnosis of dementia in adults with Down syndrome via structural imaging markers of cerebrovascular disease and atrophy. The study included participants with Down syndrome from the Alzheimer's Disease - Down Syndrome study (n = 195, age = 50.6 ± 7.2 years, 44% women, 18% diagnosed with dementia). Higher pulse pressure was associated with greater global, parietal and occipital white matter hyperintensity volume but not with enlarged perivascular spaces, microbleeds or infarcts. Using a structural equation model, we found that pulse pressure was associated with greater white matter hyperintensity volume, which in turn was related to increased neurodegeneration, and subsequent dementia diagnosis. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.

Phenotyping Down syndrome: discovery and predictive modelling with electronic medical records

BACKGROUND

Individuals with Down syndrome (DS) have a heightened risk for various co-occurring health conditions, including congenital heart disease (CHD). In this two-part study, electronic medical records (EMRs) were leveraged to examine co-occurring health conditions among individuals with DS (Study 1) and to investigate health conditions linked to surgical intervention among DS cases with CHD (Study 2).

METHODS

De-identified EMRs were acquired from Vanderbilt University Medical Center and facilitated creating a cohort of N = 2282 DS cases (55% females), along with comparison groups for each study. In Study 1, DS cases were one-by-two sex and age matched with samples of case-controls and of individuals with other intellectual and developmental difficulties (IDDs). The phenome-disease association study (PheDAS) strategy was employed to reveal co-occurring health conditions in DS versus comparison groups, which were then ranked for how often they are discussed in relation to DS using the PubMed database and Novelty Finding Index. In Study 2, a subset of DS individuals with CHD [N = 1098 (48%)] were identified to create longitudinal data for N = 204 cases with surgical intervention (19%) versus 204 case-controls. Data were included in predictive models and assessed which model-based health conditions, when more prevalent, would increase the likelihood of surgical intervention.

RESULTS

In Study 1, relative to case-controls and those with other IDDs, co-occurring health conditions among individuals with DS were confirmed to include heart failure, pulmonary heart disease, atrioventricular block, heart transplant/surgery and primary pulmonary hypertension (circulatory); hypothyroidism (endocrine/metabolic); and speech and language disorder and Alzheimer's disease (neurological/mental). Findings also revealed more versus less prevalent co-occurring health conditions in individuals with DS when comparing with those with other IDDs. Findings with high Novelty Finding Index were abnormal electrocardiogram, non-rheumatic aortic valve disorders and heart failure (circulatory); acid-base balance disorder (endocrine/metabolism); and abnormal blood chemistry (symptoms). In Study 2, the predictive models revealed that among individuals with DS and CHD, presence of health conditions such as congestive heart failure (circulatory), valvular heart disease and cardiac shunt (congenital), and pleural effusion and pulmonary collapse (respiratory) were associated with increased likelihood of surgical intervention.

CONCLUSIONS

Research efforts using EMRs and rigorous statistical methods could shed light on the complexity in health profile among individuals with DS and other IDDs and motivate precision-care development.

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.

Long-Term Outcomes in Patients With Trisomy 21 and Obstructive Sleep Apnea

OBJECTIVE

To better understand the long-term health implications of obstructive sleep apnea (OSA) on patients with Trisomy 21 (T21) and the role of sleep surgery as a therapeutic intervention.

STUDY DESIGN

Retrospective large database review.

SETTING

The prevalence of OSA is as high as 75% in patients with T21. We sought to examine the cardiovascular, neurological, and endocrinological outcomes of patients with T21 10 years after their diagnosis of OSA.

METHODS

TriNetX, an electronic medical record database, was queried for health outcomes in patients with T21 after diagnosis of OSA. The group was further analyzed to identify those who underwent sleep surgery, including hypoglossal nerve stimulation, palatopharyngoplasty, or adenotonsillectomy.

RESULTS

Ten years after diagnosis, patients with OSA and T21 had a significantly higher incidence of death, myocardial infarction, cerebral infarction, heart failure, cardiac arrhythmia, ischemic heart disease, atrial fibrillation, essential hypertension, pulmonary hypertension, diabetes mellitus, and Alzheimer's disease compared to patients with T21 alone. Patients with OSA and T21 who underwent sleep surgery had significantly reduced incidence of adverse health outcomes compared to patients using continuous positive airway pressure.

CONCLUSION

Our findings suggest that patients with T21 and OSA are at higher risk of poor health outcomes, which may require closer monitoring for earlier diagnosis and management of comorbid conditions. Sleep surgery is a suitable treatment modality for mitigating the risk of adverse outcomes in this population and should be considered in patients who are eligible surgical candidates.

Co-occurring conditions in Down syndrome: Findings from a clinical database

Individuals with Down syndrome (DS) experience a range of medical and neurodevelopmental conditions, necessitating systematic study of their occurrence and impact on neurodevelopmental outcomes. We describe the prevalence and relationships of medical, neurodevelopmental (ND), and mental health (MH) conditions in children with DS. We created a prospective clinical database of individuals with DS, integrated into the workflow of a specialty Down Syndrome Program at a specialty pediatric referral hospital. Conditions were collected through caregiver- and clinician report at clinical visits (N = 599). We calculated frequencies of medical, ND, and MH conditions and then assessed the relationship between medical, ND, and MH conditions using frequencies and comparative statistics. The most frequent co-occurring conditions were vision (72.5%), ear/hearing (71.0%), gastrointestinal (61.3%), respiratory (45.6%), and feeding (33.6%) problems, with variation in frequency by age. ND and MH conditions were reported in one quarter, most commonly autism spectrum disorder and attention-deficit/hyperactivity disorder. Those with ND and MH conditions had greater frequency of medical conditions, with highest rates of vision, ear/hearing, and gastrointestinal issues, and CHD. Systematically collected clinical data in a large cohort of children with DS reveals high prevalence of several co-occurring medical, ND, and MH conditions. Clinical care requires an understanding of the complex relationship between medical conditions and neurodevelopment.

Ultrasonic vocalization phenotypes in the Ts65Dn and Dp(16)1Yey mouse models of Down syndrome

Down syndrome (DS) is a developmental disorder associated with a high incidence of challenges in vocal communication. DS can involve medical co-morbidities and structural social factors that may impact communication outcomes, which can present difficulties for the study of vocal communication challenges. Mouse models of DS may be used to study vocal communication differences associated with this syndrome and allow for greater control and consistency of environmental factors. Prior work has demonstrated differences in ultrasonic vocalization (USV) of the Ts65Dn mouse model of DS at a young adult age, however it is not known how USV characteristics are manifested at mature ages. Given that the aging process and age-related co-morbidities may also impact communication in DS, addressing this gap in knowledge may be of value for efforts to understand communication difficulties in DS across the lifespan. The current study hypothesized that the Ts65Dn and Dp(16)1Yey mouse models of DS would demonstrate differences in multiple measures of USV communication at a mature adult age of 5 months.

METHODS

Ts65Dn mice (n = 16) and euploid controls (n = 19), as well as Dp(16)1Yey mice (n = 20) and wild-type controls (n = 22), were evaluated at 5 months of age for USV production using a mating paradigm. Video footage of USV sessions were analyzed to quantify social behaviors of male mice during USV testing sessions. USV recordings were analyzed using Deepsqueak software to identify 10 vocalization types, which were quantified for 11 acoustic measures.

RESULTS

Ts65Dn, but not Dp(16)1Yey, showed significantly lower proportions of USVs classified as Step Up, Short, and Frequency Steps, and significantly higher proportions of USVs classified as Inverted U, than euploid controls. Both Ts65Dn and Dp(16)1Yey groups had significantly greater values for power and tonality for USVs than respective control groups. While Ts65Dn showed lower frequencies than controls, Dp(16)1Yey showed higher frequencies than controls. Finally, Ts65Dn showed reductions in a measure of complexity for some call types. No significant differences between genotype groups were identified in analysis of behaviors during testing sessions.

CONCLUSION

While both Ts65Dn and Dp(16)1Yey show significant differences in USV measures at 5 months of age, of the two models, Ts65Dn shows a relatively greater numbers of differences. Characterization of communication phenotypes in mouse models of DS may be helpful in laying the foundation for future translational advances in the area of communication difficulties associated with DS.

Pathways linking pulse pressure to dementia in adults with Down syndrome

Individuals with Down syndrome (DS) are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease, entorhinal cortical atrophy, and diagnosis of dementia in adults with DS. Participants with DS from the Biomarkers of Alzheimer's Disease in Adults with Down Syndrome study (ADDS; n=195, age=50.6±7.2 years, 44% women, 18% diagnosed with dementia) were included. Higher pulse pressure was associated with greater global, parietal, and occipital WMH volume. Pulse pressure was not related to enlarged PVS, microbleeds, infarcts, entorhinal cortical thickness, or dementia diagnosis. However, in a serial mediation model, we found that pulse pressure was indirectly related to dementia diagnosis through parieto-occipital WMH and, subsequently through entorhinal cortical thickness. Higher pulse pressure may be a risk factor for dementia in people with DS by promoting cerebrovascular disease, which in turn affects neurodegeneration. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.

Single-Nucleus Profiling Identifies Accelerated Oligodendrocyte Precursor Cell Senescence in a Mouse Model of Down Syndrome

Down syndrome (DS), the most common genetic cause of intellectual disability, is associated with lifelong cognitive deficits. However, the mechanisms by which triplication of chromosome 21 genes drive neuroinflammation and cognitive dysfunction are poorly understood. Here, using the Ts65Dn mouse model of DS, we performed an integrated single-nucleus ATAC and RNA-sequencing (snATAC-seq and snRNA-seq) analysis of the adult cortex. We identified cell type-specific transcriptional and chromatin-associated changes in the Ts65Dn cortex, including regulators of neuroinflammation, transcription and translation, myelination, and mitochondrial function. We discovered enrichment of a senescence-associated transcriptional signature in Ts65Dn oligodendrocyte (OL) precursor cells (OPCs) and epigenetic changes consistent with a loss of heterochromatin. We found that senescence is restricted to a subset of OPCs concentrated in deep cortical layers. Treatment of Ts65Dn mice with a senescence-reducing flavonoid rescued cortical OPC proliferation, restored microglial homeostasis, and improved contextual fear memory. Together, these findings suggest that cortical OPC senescence may be an important driver of neuropathology in DS.

Multiple morbidity across the lifespan in people with Down syndrome or intellectual disabilities: a population-based cohort study using electronic health records

BACKGROUND

The Down syndrome phenotype is well established, but our understanding of its morbidity patterns is limited. We comprehensively estimated the risk of multiple morbidity across the lifespan in people with Down syndrome compared with the general population and controls with other forms of intellectual disability.

METHODS

In this matched population-based cohort-study design, we used electronic health-record data from the UK Clinical Practice Research Datalink (CRPD) from Jan 1, 1990, to June 29, 2020. We aimed to explore the pattern of morbidities throughout the lifespan of people with Down syndrome compared with people with other intellectual disabilities and the general population, to identify syndrome-specific health conditions and their age-related incidence. We estimated incidence rates per 1000 person-years and incidence rate ratios (IRRs) for 32 common morbidities. Hierarchical clustering was used to identify groups of associated conditions using prevalence data.

FINDINGS

Between Jan 1, 1990, and June 29, 2020, a total of 10 204 people with Down syndrome, 39 814 controls, and 69 150 people with intellectual disabilities were included. Compared with controls, people with Down syndrome had increased risk of dementia (IRR 94·7, 95% CI 69·9-128·4), hypothyroidism (IRR 10·6, 9·6-11·8), epilepsy (IRR 9·7, 8·5-10·9), and haematological malignancy (IRR 4·7, 3·4-6·3), whereas asthma (IRR 0·88, 0·79-0·98), cancer (solid tumour IRR 0·75, 0·62-0·89), ischaemic heart disease (IRR 0·65, 0·51-0·85), and particularly hypertension (IRR 0·26, 0·22-0·32) were less frequent in people with Down syndrome than in controls. Compared to people with intellectual disabilities, risk of dementia (IRR 16·60, 14·23-19·37), hypothyroidism (IRR 7·22, 6·62-7·88), obstructive sleep apnoea (IRR 4·45, 3·72-5·31), and haematological malignancy (IRR 3·44, 2·58-4·59) were higher in people with Down syndrome, with reduced rates for a third of conditions, including new onset of dental inflammation (IRR 0·88, 0·78-0·99), asthma (IRR 0·82, 0·73-0·91), cancer (solid tumour IRR 0·78, 0·65-0·93), sleep disorder (IRR 0·74, 0·68-0·80), hypercholesterolaemia (IRR 0·69, 0·60-0·80), diabetes (IRR 0·59, 0·52-0·66), mood disorder (IRR 0·55, 0·50-0·60), glaucoma (IRR 0·47, 0·29-0·78), and anxiety disorder (IRR 0·43, 0·38-0·48). Morbidities in Down syndrome could be categorised on age-related incidence trajectories, and their prevalence clustered into typical syndromic conditions, cardiovascular diseases, autoimmune disorders, and mental health conditions.

INTERPRETATION

Multiple morbidity in Down syndrome shows distinct patterns of age-related incidence trajectories and clustering that differ from those found in the general population and in people with other intellectual disabilities, with implications for provision and timing of health-care screening, prevention, and treatment for people with Down syndrome.

FUNDING

The European Union's Horizon 2020 Research and Innovation Programme, the Jérôme Lejeune Foundation, the Alzheimer's Society, the Medical Research Council, the Academy of Medical Sciences, the Wellcome Trust, and William Harvey Research Limited.

Complement dysregulation and Alzheimer's disease in Down syndrome

INTRODUCTION

Down syndrome (DS) is associated with immune dysregulation and a high risk of early onset Alzheimer's disease (AD). Complement is a key part of innate immunity and driver of pathological inflammation, including neuroinflammation in AD. Complement dysregulation has been reported in DS; however, the pattern of dysregulation and its relationship to AD risk is unclear.

METHODS

Plasma levels of 14 complement biomarkers were measured in 71 adults with DS and 46 controls to identify DS-associated dysregulation; impact of apolipoprotein E (APOE) ε4 genotype, single nucleotide polymorphisms (SNPs) in CLU and CR1, and dementia on complement biomarkers was assessed.

RESULTS

Plasma levels of complement activation products (TCC, iC3b), proteins (C1q, C3, C9), and regulators (C1 inhibitor, factor H, FHR4, clusterin) were significantly elevated in DS versus controls while FI and sCR1 were significantly lower. In DS with AD (n = 13), C3 and FI were significantly decreased compared to non-AD DS (n = 58). Neither APOE genotype nor CLU SNPs impacted complement levels, while rs6656401 in CR1 significantly impacted plasma sCR1 levels.

CONCLUSIONS

Complement is dysregulated in DS, likely reflecting the generalized immune dysregulation state; measurement may help identify inflammatory events in individuals with DS. Complement biomarkers differed in DS with and without AD and may aid diagnosis and/or prediction.

HIGHLIGHTS

Complement is significantly dysregulated in plasma of people with DS who show changes in levels of multiple complement proteins compared to controls. People with DS and dementia show evidence of additional complement dysregulation with significantly lower levels of C3 and factor I compared to those without dementia. rs6656401 in CR1 was associated with significantly elevated sCR1 plasma levels in DS.

Adherence to CPAP therapy in Down syndrome: the population-based DISCOVERY study

STUDY OBJECTIVES

Persons with Down syndrome (DS) have an increased risk of obstructive sleep apnea (OSA) needing continuous positive airway pressure (CPAP), but data on the therapy and outcomes in this population are scarce. We aimed to compare patient characteristics and outcomes of CPAP treatment for patients with OSA with and without DS.

METHODS

This was a population-based, longitudinal study on patients initiating CPAP therapy between July 2010 and March 2018 in Sweden and a population-based sex- and age-matched control group (control:case ratio 5:1), with linked data from the Swedish National Patient Registry and the Prescribed Drug Registry (DISCOVERY study cohort).

RESULTS

Patients with DS (n = 64) had a higher apnea-hypopnea index (51.7 ± 30.3 vs 36.8 ± 29.1 events/h, P < .001), Epworth Sleepiness Scale score (13.7 ± 5.9 vs 11.0 ± 4.9, P = .001), rate of previous surgery of tonsils and/or adenoids (21.9% vs 8.2%, P = .001), and more thyroid replacement hormone therapy (45.3% vs 7.8%, P < .001), but lower use of cardiovascular drugs (7.8% vs 22.3%, P = .003) compared with controls. At follow-up after 1.3 ± 0.9 years, there were no differences in nocturnal CPAP usage time (5.6 ± 2.4 vs 5.5 ± 2.0 hours, P = .77), CPAP adherence ≥ 4 hours/night (62% vs 65%, P = .93), or improvement in Epworth Sleepiness Scale score (-5.4 ± 6.8 vs -5.0 ± 2.0, P = .84) between DS and non-DS patients.

CONCLUSIONS

OSA severity was substantially higher in patients with DS despite an increased rate of tonsil surgery. Treatment outcomes in terms of adherence and improved daytime sleepiness were comparable between groups, underlining the importance of both OSA diagnosis and treatment in patients with DS.

CITATION

Svensson M, Ekström M, Sundh J, Ljunggren M, Grote L, Palm A. Adherence to CPAP therapy in Down syndrome: the population-based DISCOVERY study. J Clin Sleep Med. 2023;19(3):453-458.

Psychological capital, quality of life, and well-being in mother caregivers of individuals with down syndrome

Introduction

Caused by an error in cell division that produces an additional chromosome 21, Down syndrome (DS) is one of the most common developmental disorders in the world. This study aims to analyze the relationship between psychological capital, quality of life and well-being of caregivers of individuals with Down syndrome (DS).

Methods

The participants were 98 caregivers (mothers, M = 52.13, SD = 11.39) of individuals with Down syndrome. The instruments used were the Psychological Capital Questionnaire (measuring self-efficacy, resilience, optimism, and hope), Quality of Life Questionnaire (including social support, general satisfaction, physical/psychological health, absence of excessive workload/free time), and Psychological Wellbeing Scale, investigating the following dimensions: self-acceptance, positive relationships with others, autonomy, environmental mastery, purpose in life, and personal growth.

Results

The mediation analysis showed that self-efficacy, hope, and resilience are positively associated to quality of life, and optimism is positively associated to well-being. The total effects of psychological capital on well-being are positive and significant and quality of life mediates the relationship between psychological capital and well-being.

Discussion

These results show that psychological capital is an important inner resource for caregivers of DS individuals and must be improved through support services, so that caregivers have a higher perception of the quality of life and implicitly of well-being.

IGF1 deficiency integrates stunted growth and neurodegeneration in Down syndrome

Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is characterized by stunted growth, cognitive impairment, and increased risk of diverse neurological conditions. Although signs of lifelong neurodegeneration are well documented in DS, the mechanisms underlying this phenotype await elucidation. Here we report a multi-omics analysis of neurodegeneration and neuroinflammation biomarkers, plasma proteomics, and immune profiling in a diverse cohort of more than 400 research participants. We identified depletion of insulin growth factor 1 (IGF1), a master regulator of growth and brain development, as the top biosignature associated with neurodegeneration in DS. Individuals with T21 display chronic IGF1 deficiency downstream of growth hormone production, associated with a specific inflammatory profile involving elevated tumor necrosis factor alpha (TNF-α). Shorter children with DS show stronger IGF1 deficiency, elevated biomarkers of neurodegeneration, and increased prevalence of autism and other conditions. These results point to disruption of IGF1 signaling as a potential contributor to stunted growth and neurodegeneration in DS.

Pediatric Population with Down Syndrome: Obesity and the Risk of Cardiovascular Disease and Their Assessment Using Omics Techniques-Review

People with Down syndrome (PWDS) are more at risk for developing obesity, oxidative stress disorders, metabolic disorders, and lipid and carbohydrate profile disorders than the general population. The presence of an additional copy of genes on chromosome 21 (i.e., the superoxide dismutase 1 gene (SOD1) and gene coding for the cystathionine β-synthase (CBS) enzyme) raises the risk for cardiovascular disease (CVD). As a result of disorders in metabolic processes and biochemical pathways, theoretically protective factors (low homocysteine level, high SOD1 level) do not fulfil their original functions. Overexpression of the CBS gene leads to the accumulation of homocysteine-a CVD risk factor. An excessive amount of protective SOD1, in the case of a lack of compensatory increase in the activity of catalase and peroxidase, leads to intensifying free radical processes. The occurrence of metabolic disorders and the amplified effect of oxidative stress carries higher risk of exposure of people with DS to CVD. At present, classic predispositions are known, but it is necessary to identify early risk factors in order to be able to employ CVD and obesity prophylaxis. Detailed determination of the metabolic and lipid profile may provide insight into the molecular mechanisms underlying CVD.

Physical Activity and Physical and Mental Health in Middle-Aged Adults with Down Syndrome

Background

Adults with Down syndrome have an increased risk of aging-related physical and mental health conditions and experience them at an earlier age than the general population. There is a need to investigate modifiable lifestyle factors that may reduce risk for these conditions.

Method

The present study investigated the associations between physical activity (i.e., sedentary behavior and moderate-to-vigorous activity) assessed via accelerometer across 7 days and caregiver-reported physical and mental health of 66 non-demented middle-aged adults with Down Syndrome aged 25-55 years (52% female).

Results

Regression analyses indicated that more time spent in moderate intensity physical activity was associated with less risk of sleep apnea (b = -.031 p = .004) and endocrine/metabolic conditions (b = -.046 p = .009), and lower total number of physical health conditions (b = -.110 p =.016) and anxiety disorders (b = -.021 p =.049) after controlling for relevant sociodemographics. After also adjusting for BMI, the association between time spent in moderate intensity physical activity and sleep apnea (b=-.035, p = .002), endocrine/metabolic conditions (b=-.033, p = .045) and total physical health (b=-.091, p =.026) remained significant Unexpectedly, time spent in sedentary behavior was negatively associated with musculoskeletal conditions (b=-.017, p = .044).

Conclusion

Findings indicate important associations between physical activity in everyday life and the physical and mental health of adults with Down syndrome. Social policies and interventions aimed at reducing time spent sitting around (i.e., sedentary behavior) and encouraging moderate-to-vigorous activity may be a low-burden and low-cost mechanism for fostering healthy physical and mental aging in the Down syndrome population.

Comorbidity of osteoporosis and Alzheimer's disease: Is `AKT `-ing on cellular glucose uptake the missing link?

Osteoporosis and Alzheimer's disease (AD) are both degenerative diseases. Osteoporosis often proceeds cognitive deficits, and multiple studies have revealed common triggers that lead to energy deficits in brain and bone. Risk factors for osteoporosis and AD, such as obesity, type 2 diabetes, aging, chemotherapy, vitamin deficiency, alcohol abuse, and apolipoprotein Eε4 and/or Il-6 gene variants, reduce cellular glucose uptake, and protective factors, such as estrogen, insulin, exercise, mammalian target of rapamycin inhibitors, hydrogen sulfide, and most phytochemicals, increase uptake. Glucose uptake is a fine-tuned process that depends on an abundance of glucose transporters (Gluts) on the cell surface. Gluts are stored in vesicles under the plasma membrane, and protective factors cause these vesicles to fuse with the membrane, resulting in presentation of Gluts on the cell surface. This translocation depends mainly on AKT kinase signaling and can be affected by a range of factors. Reduced AKT kinase signaling results in intracellular glucose deprivation, which causes endoplasmic reticulum stress and iron depletion, leading to activation of HIF-1α, the transcription factor necessary for higher Glut expression. The link between diseases and aging is a topic of growing interest. Here, we show that diseases that affect the same biochemical pathways tend to co-occur, which may explain why osteoporosis and/or diabetes are often associated with AD.

Cardiovascular Physiology and Pathophysiology in Down Syndrome

Down Syndrome (Ds) is the most common chromosomal cause of intellectual disability that results from triplication of chromosome 21 genes. Individuals with Ds demonstrate cognitive deficits in addition to comorbidities including cardiac defects, pulmonary arterial hypertension (PAH), low blood pressure (BP), and differences in autonomic regulation. Many individuals with Ds are born with heart malformations and some can be surgically corrected. Lower BP at rest and in response to exercise and other stressors are a prevalent feature in Ds. These reduced cardiovascular responses may be due to underlying autonomic dysfunction and have been implicated in lower exercise/work capacity in Ds, which is an important correlate of morbidity, mortality and quality of life. Exercise therapy can be beneficial to normalize autonomic function and may help prevent the development of co-morbidities in Ds. We will review cardiovascular physiology and pathophysiology in individuals with Ds, along with exercise therapy and special considerations for these individuals.

Prevalence of Mental Health Conditions Among 6078 Individuals With Down Syndrome in the United States

Findings from a recent study of the largest documented cohort of individuals with Down syndrome (DS) in the United States described prevalence of common disease conditions and strongly suggested significant disparity in mental health conditions among these individuals as compared with age- and sex-matched individuals without DS. The retrospective, descriptive study reported herein is a follow-up to document prevalence of 58 mental health conditions across 28 years of data from 6078 individuals with DS and 30,326 age- and sex-matched controls. Patient data were abstracted from electronic medical records within a large integrated health system. In general, individuals with DS had higher prevalence of mood disorders (including depression); anxiety disorders (including obsessive-compulsive disorder); schizophrenia; psychosis (including hallucinations); pseudobulbar affect; personality disorder; dementia (including Alzheimer's disease); mental disorder due to physiologic causes; conduct disorder; tic disorder; and impulse control disorder. Conversely, the DS cohort experienced lower prevalence of bipolar I disorder; generalized anxiety, panic, phobic, and posttraumatic stress disorders; substance use disorders (including alcohol, opioid, cannabis, cocaine, and nicotine disorders); and attention-deficit/hyperactivity disorder. Prevalence of many mental health conditions in the setting of DS vastly differs from comparable individuals without DS. These findings delineate a heretofore unclear jumping-off point for ongoing research.

Prevalence of Infectious Diseases Among 6078 Individuals With Down Syndrome in the United States

A recent disease prevalence study of the largest documented Down syndrome (DS) cohort in the United States strongly suggested significant disparity in general infectious disease conditions among individuals with DS versus those without DS. In this follow-up retrospective analysis, we explored these differences in greater detail by calculating prevalence of 52 infectious diseases, across 28 years of data among 6078 individuals with DS and 30,326 age- and sex-matched controls, abstracted from electronic medical records within a large Midwestern health system. We found that the DS cohort had higher prevalence of pneumonias (including aspiration, viral, bacterial, pneumococcal, and unspecified/atypical); otitis externa; and the skin infections impetigo, abscess, and cellulitis. To the contrary, the DS cohort had lower prevalence of many respiratory infections other than pneumonia (including influenza, strep pharyngitis, upper respiratory infection, sinusitis, tonsillitis, laryngitis, bronchitis, scarlet fever, and otitis media); sexually transmitted infections (including bacterial vaginosis, chlamydia, genital herpes, HIV/AIDS, human papillomavirus, pelvic inflammatory disease, and trichomoniasis); mononucleosis; shingles; unspecified hepatitis; intestinal infections; and enteritis. These findings highlight that individuals with DS could be more or less prone to different infectious diseases than their non-DS matched counterparts. Additional research to understand why these differences exist and how they might affect the clinical approach to patients with DS is warranted.

Buspirone for the Treatment of Generalized Anxiety Disorder in Down Syndrome: 3 Cases

OBJECTIVE

Reports on the pharmacologic treatment of anxiety, including generalized anxiety disorder (GAD), in individuals with Down syndrome (DS) are lacking.

METHODS

We present the case histories of 1 adolescent and 2 young adults with DS and the treatment course of comorbid GAD with buspirone.

RESULTS

Treatment with buspirone was safe and well-tolerated and resulted in sustained improvement in symptoms of anxiety for a minimum of 2 years in all 3 cases.

CONCLUSION

Buspirone's generally benign adverse effect profile makes it well suited for treating anxiety in individuals with DS in light of their common medical comorbidities.

Prevalence of Endocrine Disorders Among 6078 Individuals With Down Syndrome in the United States

Findings from a recent study describing prevalence of common disease conditions in the largest documented cohort of individuals with Down syndrome (DS) in the United States strongly suggested significant disparity in endocrine disorders among these individuals when compared with age- and sex-matched individuals without DS. This retrospective, descriptive study is a follow-up report documenting prevalence of 21 endocrine disorder conditions, across 28 years of data, from 6078 individuals with DS and 30,326 age- and sex-matched controls, abstracted from electronic medical records within a large integrated health system. Overall, individuals with DS experienced higher prevalence of adrenal insufficiency and Addison's disease; thyroid disorders, including hypothyroidism, hyperthyroidism, Hashimoto's disease, and Graves' disease; prolactinoma/hyperprolactinemia; diabetes insipidus; type I diabetes mellitus; and gout. Conversely, those with DS had lower prevalence of polycystic ovary syndrome and type II diabetes mellitus. Many prevalences of endocrine conditions seen in individuals with DS significantly differ relative to their non-DS matched counterparts. These varied findings warrant further exploration into how screening for and treatment of endocrine conditions may need to be approached differently for individuals with DS.

The Clinical and Neuropathological Features of Sporadic (Late-Onset) and Genetic Forms of Alzheimer's Disease

The purpose of this review is to compare and highlight the clinical and pathological aspects of genetic versus acquired Alzheimer's disease: Down syndrome-associated Alzheimer's disease in (DSAD) and Autosomal Dominant Alzheimer's disease (ADAD) are compared with the late-onset form of the disease (LOAD). DSAD and ADAD present in a younger population and are more likely to manifest with non-amnestic (such as dysexecutive function features) in the prodromal phase or neurological features (such as seizures and paralysis) especially in ADAD. The very large variety of mutations associated with ADAD explains the wider range of phenotypes. In the LOAD, age-associated comorbidities explain many of the phenotypic differences.

Comprehensive phenotypic analysis of the Dp1Tyb mouse strain reveals a broad range of Down syndrome-related phenotypes

Down syndrome (DS), trisomy 21, results in many complex phenotypes including cognitive deficits, heart defects and craniofacial alterations. Phenotypes arise from an extra copy of human chromosome 21 (Hsa21) genes. However, these dosage-sensitive causative genes remain unknown. Animal models enable identification of genes and pathological mechanisms. The Dp1Tyb mouse model of DS has an extra copy of 63% of Hsa21-orthologous mouse genes. In order to establish whether this model recapitulates DS phenotypes, we comprehensively phenotyped Dp1Tyb mice using 28 tests of different physiological systems and found that 468 out of 1800 parameters were significantly altered. We show that Dp1Tyb mice have wide-ranging DS-like phenotypes, including aberrant erythropoiesis and megakaryopoiesis, reduced bone density, craniofacial changes, altered cardiac function, a pre-diabetic state, and deficits in memory, locomotion, hearing and sleep. Thus, Dp1Tyb mice are an excellent model for investigating complex DS phenotype-genotype relationships for this common disorder.

Repeat tympanostomy tubes in children with Down syndrome

OBJECTIVES

Children with Down syndrome (DS) have a higher incidence of tympanostomy tube insertion (TTI) than children in the general population. As there were no studies investigating factors that are associated with multiple TTIs in children with DS, we sought to determine what factors increase or decrease the likelihood of repeat TTI in children with DS.

METHODS

A retrospective case-control study was performed on consecutive children with DS from 2007 to 2018 with first TTI at a large tertiary children's hospital and follow-up duration at least 27 months since first TTI.

RESULTS

277 patients met the inclusion criteria. Repeat TTI rate was 61.4%. Having an indication of chronic otitis media with effusion (COME) at first TTI was an adjusted risk factor for increased rate of repeat TTI (OR: 2.01, 95%CI: 1.15-3.51, p = .014), while being older at first TTI was an adjusted protective factor for decreased rate of repeat TTI (OR: 0.84, 95%CI: 0.74-0.95, p = .004). Adenotonsillectomy at or before first TTI was not an adjusted protective factor for decreased rate of repeat TTI (OR: 0.915, 95%CI: 0.448-1.872, p = .809) and bilateral intra-operative fluid was not an adjusted risk factor for repeat TTI (OR: 1.97, 95%CI: 0.99-3.90, p = .054).

CONCLUSION

Children with DS were more likely to undergo repeat TTI if they were of younger age and if the indication for surgery was COME. The repeat TTI rate for children with DS was high at 61.4%. Prospective studies are warranted to more precisely investigate factors associated with repeat TTIs in this unique patient population.

Transcriptome and metabolome analysis of crGART, a novel cell model of de novo purine synthesis deficiency: Alterations in CD36 expression and activity

In humans, GART [phosphoribosylglycinamide formyltransferase (EC 2.1.2.2) / phosphoribosylglycinamide synthetase (EC 6.3.4.13) / phosphoribosylaminoimidazole synthetase (EC 6.3.3.1)] is a trifunctional protein which catalyzes the second, third, and fifth reactions of the ten step de novo purine synthesis (DNPS) pathway. The second step of DNPS is conversion of phosphoribosylamine (5-PRA) to glycineamide ribonucleotide (GAR). 5-PRA is extremely unstable under physiological conditions and is unlikely to accumulate in the absence of GART activity. Recently, a HeLa cell line null mutant for GART was constructed via CRISPR-Cas9 mutagenesis. This cell line, crGART, is an important cellular model of DNPS inactivation that does not accumulate DNPS pathway intermediates. In the current study, we characterized the crGART versus HeLa transcriptomes in purine-supplemented and purine-depleted growth conditions. We observed multiple transcriptome changes and discuss pathways and ontologies particularly relevant to Alzheimer disease and Down syndrome. We selected the Cluster of Differentiation (CD36) gene for initial analysis based on its elevated expression in crGART versus HeLa as well as its high basal expression, high log2 value, and minimal P-value.

Genetic Susceptibility to Periodontal Disease in Down Syndrome: A Case-Control Study

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis (n = 50) and DS patients with healthy periodontium (n = 36). All samples were genotyped with the “Axiom Spanish Biobank” array, which contains 757,836 markers. An association analysis at the individual marker level using logistic regression, as well as at the gene level applying the sequence kernel association test (SKAT) was performed. The most significant genes were included in a pathway analysis using the free DAVID software. C12orf74 (rs4315121, p = 9.85 × 10⁻⁵, OR = 8.84), LOC101930064 (rs4814890, p = 9.61 × 10⁻⁵, OR = 0.13), KBTBD12 (rs1549874, p = 8.27 × 10⁻⁵, OR = 0.08), PIWIL1 (rs11060842, p = 7.82 × 10⁻⁵, OR = 9.05) and C16orf82 (rs62030877, p = 8.92 × 10⁻⁵, OR = 0.14) showed a higher probability in the individual analysis. The analysis at the gene level highlighted PIWIL, MIR9-2, LHCGR, TPR and BCR. At the signaling pathway level, PI3K-Akt, long-term depression and FoxO achieved nominal significance (p = 1.3 × 10⁻², p = 5.1 × 10⁻³, p = 1.2 × 10⁻², respectively). In summary, various metabolic pathways are involved in the pathogenesis of periodontitis in DS, including PI3K-Akt, which regulates cell proliferation and inflammatory response.

Prospective Associations of Physical Activity and Health-Related Physical Fitness in Adolescents with Down Syndrome: The UP&DOWN Longitudinal Study

(1) Background: Numerous studies have focused on examining the association between PA levels and health-related physical fitness components in children or adolescents without disabilities. However, research on the association between PA and health-related physical fitness in adolescents with DS (Down syndrome) is limited, and most of the previous studies have been developed with a cross-sectional perspective. Therefore, the aim of the present study was to assess the prospective association of accelerometer-based PA at baseline with health-related physical fitness at a 2-year follow-up in a relatively large sample of adolescents with DS from the UP&DOWN study. (2) Methods: A total of 92 adolescents with DS (58 males) between 11 and 20 years old with full data were eligible from an initial sample of 110 participants. Fitness was assessed by the ALPHA health-related fitness test battery for youth, and physical activity was assessed by Actigraph accelerometers. (3) Results: The high tertile of total PA was related to decreased motor (Beta [95% CI] = −1.46 [−2.88; −0.05]) and cardiorespiratory fitness (Beta [95% CI] = −2.22 [−4.42; 0.02]) in adolescents with DS. (4) Conclusions: In adolescents with DS, (i) PA level was not prospectively associated with muscular fitness and (ii) high levels of total PA at the baseline were inversely associated with motor and cardiorespiratory fitness at the 2-year follow-up. For comparative purposes, these relationships were also examined in a subsample of adolescents without DS.

Prevalence of Common Disease Conditions in a Large Cohort of Individuals With Down Syndrome in the United States

Purpose

Given the current life expectancy and number of individuals living with Down syndrome (DS), it is important to learn common occurrences of disease conditions across the developmental lifespan. This study analyzed data from a large cohort of individuals with DS in an effort to better understand these disease conditions, inform future screening practices, tailor medical care guidelines, and improve utilization of health care resources.

Methods

This retrospective, descriptive study incorporated up to 28 years of data, compiled from 6078 individuals with DS and 30,326 controls matched on age and sex. Data were abstracted from electronic medical records within a large Midwestern health system.

Results

In general, individuals with DS experienced higher prevalence of testicular cancer, leukemias, moyamoya disease, mental health conditions, bronchitis and pneumonia, gastrointestinal conditions, thyroid disorder, neurological conditions, atlantoaxial subluxation, osteoporosis, dysphagia, diseases of the eyes/adnexa and of the ears/mastoid process, and sleep apnea, relative to matched controls. Individuals with DS experienced lower prevalence of solid tumors, heart disease conditions, sexually transmitted diseases, HIV, influenza, sinusitis, urinary tract infections, and diabetes. Similar rates of prevalence were seen for lymphomas, skin melanomas, stroke, acute myocardial infarction, hepatitis, cellulitis, and osteoarthritis.

Conclusions

While it is challenging to draw a widespread conclusion about comorbidities in individuals with Down syndrome, it is safe to conclude that care for individuals with DS should not automatically mirror screening, prevention, or treatment guidelines for the general U.S. population. Rather, care for those with DS should reflect the unique needs and common comorbidities of this population.

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.

Individuals with Down syndrome hospitalized with COVID-19 have more severe disease

PURPOSE

Rare genetic conditions like Down syndrome (DS) are historically understudied. Infection is a leading cause of mortality in DS, along with cardiac anomalies. Currently, it is unknown how the COVID-19 pandemic affects individuals with DS. Herein, we report an analysis of individuals with DS who were hospitalized with COVID-19 in New York, New York, USA.

METHODS

In this retrospective, dual-center study of 7246 patients hospitalized with COVID-19, we analyzed all patients with DS admitted in the Mount Sinai Health System and Columbia University Irving Medical Center. We assessed hospitalization rates, clinical characteristics, and outcomes.

RESULTS

We identified 12 patients with DS. Hospitalized individuals with DS are on average ten years younger than patients without DS. Patients with DS have more severe disease than controls, particularly an increased incidence of sepsis and mechanical ventilation.

CONCLUSION

We demonstrate that individuals with DS who are hospitalized with COVID-19 are younger than their non-DS counterparts, and that they have more severe disease than age-matched controls. We conclude that particular care should be considered for both the prevention and treatment of COVID-19 in these patients.

Rescuing Over-activated Microglia Restores Cognitive Performance in Juvenile Animals of the Dp(16) Mouse Model of Down Syndrome

Microglia are brain-resident immune cells and regulate mechanisms essential for cognitive functions. Down syndrome (DS), the most frequent cause of genetic intellectual disability, is caused by a supernumerary chromosome 21, containing also genes related to the immune system. In the hippocampus of the Dp(16) mouse model of DS and DS individuals, we found activated microglia, as assessed by their morphology; activation markers; and, for DS mice, electrophysiological profile. Accordingly, we found increased pro-inflammatory cytokine levels and altered interferon signaling in Dp(16) hippocampi. DS mice also showed decreased spine density and activity of hippocampal neurons and hippocampus-dependent cognitive behavioral deficits. Depletion of defective microglia or treatment with a commonly used anti-inflammatory drug rescued the neuronal spine and activity impairments and cognitive deficits in juvenile Dp(16) mice. Our results suggest an involvement of microglia in Dp(16)-mouse cognitive deficits and identify a new potential therapeutic approach for cognitive disabilities in DS individuals.

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DS mice display microglia alterations and cognitive impairment

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Depletion of microglia rescues cognitive impairment in DS mice

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Acetaminophen treatment rescues microglia and cognitive impairments in DS mice

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Brain samples of DS people recapitulate microglia alterations observed in DS mice

Weight status and associated comorbidities in children and adults with Down syndrome, autism spectrum disorder and intellectual and developmental disabilities

BACKGROUND

Little is known about body weight status and the association between body weight and common comorbidities in children and adults with Down syndrome (DS), autism spectrum disorder (ASD) and other intellectual and developmental disabilities (IDDs).

METHODS

Data were extracted from the University of Kansas Medical Center's Healthcare Enterprise Repository for Ontological Narration clinical integrated data repository. Measures included demographics (sex, age and race), disability diagnosis, comorbid health conditions, height, weight and body mass index percentiles (BMI%ile; <18 years of age) or BMI (≥18 years of age).

RESULTS

Four hundred and sixty-eight individuals with DS (122 children and 346 adults), 1659 individuals with ASD (1073 children and 585 adults) and 604 individuals with other IDDs (152 children and 452 adults) were identified. A total of 47.0% (DS), 41.9% (ASD) and 33.5% (IDD) of children had overweight/obese (OW/OB), respectively. Children with DS were more likely to have OW/OB compared with children with IDD or ASD [odds ratio (OR) = 1.91, 95% confidence interval (CI): (1.49, 2.46); OR = 1.43, 95% CI: (1.19, 1.72)], respectively. A total of 81.1% (DS), 62.1% (ASD), and 62.4% (IDD) of adults were OW/OB, respectively. Adults with DS were more likely to have OW/OB compared with those with IDD [OR = 2.56, 95% CI: (2.16, 3.02)]. No significant differences were observed by race. In children with ASD, higher OW/OB was associated with significantly higher (compared with non-OW/OB) occurrence of sleep apnoea [OR = 2.94, 95% CI: (2.22, 3.89)], hypothyroidism [OR = 3.14, 95% CI: (2.17, 4.25)] and hypertension [OR = 4.11, 95% CI: (3.05, 5.54)]. In adults with DS, OW/OB was significantly associated with higher risk of sleep apnoea and type 2 diabetes [OR = 2.93, 95% CI: (2.10, 4.09); OR = 1.76, 95% CI: (1.11, 2.79) respectively]. Similarly, in adults with ASD and IDD, OW/OB was significantly associated with higher risk of sleep apnoea [OR = 3.39, 95% CI: (2.37, 4.85) and OR = 6.69, 95% CI: (4.43, 10.10)], type 2 diabetes [OR = 2.25, 95 % CI: (1.68, 3.01) and OR = 5.49, 95% CI: (3.96, 7.61)] and hypertension [OR = 3.55, 95% CI: (2.76, 4.57) and 3.97, 95% CI: (3.17, 4.97)].

CONCLUSION

Findings suggest higher rates of OW/OB in individuals with DS compared with ASD and IDD. Given the increased risk of comorbidities associated with the increased risk of OW/OB, identification of effective interventions for this special population of individuals is critical.

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.

Co-occurring medical conditions in adults with Down syndrome: A systematic review toward the development of health care guidelines. Part II

Adults with Down syndrome (DS) represent a unique population who are in need of clinical guidelines to address their medical care. Many of these conditions are of public health importance with the potential to develop screening recommendations to improve clinical care for this population. Our workgroup previously identified and prioritized co-occurring medical conditions in adults with DS. In this study, we again performed detailed literature searches on an additional six medical conditions of clinical importance. A series of key questions (KQ) were formulated a priori to guide the literature search strategy. Our KQs focused on disease prevalence, severity, risk-factors, methodologies for screening/evaluation, impact on morbidity, and potential costs/benefits. The available evidence was extracted, evaluated and graded on quality. The number of participants and the design of clinical studies varied by condition and were often inadequate for answering most of the KQ. Based upon our review, we provide a summary of the findings on hip dysplasia, menopause, acquired cardiac valve disease, type 2 diabetes mellitus, hematologic disorders, and dysphagia. Minimal evidence demonstrates significant gaps in our clinical knowledge that compromises clinical decision-making and management of these medically complex individuals. The creation of evidence-based clinical guidance for this population will not be possible until these gaps are addressed.

Exploring the effectiveness of an 18-month weight management intervention in adults with Down syndrome using propensity score matching

BACKGROUND

Down syndrome (DS) is one of the most common birth defects in the USA associated with high levels of overweight and obesity. Unique characteristics of adults with DS that may contribute to the high levels of obesity are high rates of hypothyroidism, poor muscle tone, altered gait and lower resting metabolic rate. Due to these factors, it is unknown if the same weight management interventions that are effective in adults with intellectual or developmental disability (IDD) without DS are as effective in those with DS. Therefore, the purpose of this secondary analysis was to compare changes in weight, diet and physical activity between participants with DS-related and non-DS-related IDD participating in an 18-month weight management trial.

METHODS

We used propensity score methods to adjust baseline variables of overweight/obese adults with and without DS participating in an 18-month effectiveness trial with 6 months weight loss and 12 months weight maintenance. Participants followed one of two reduced calorie diet plans, obtained 150 min of moderate-vigorous intensity physical activity (MVPA) per week, and logged dietary intake daily. A health educator held monthly at-home visits with participants and a caregiver to give feedback on intervention compliance.

RESULTS

Out of the 124 participants that met the criteria for inclusion, 21 were diagnosed with DS and 103 with non-DS-related IDD. Twenty out of 21 participants with DS were successfully matched. Clinically significant weight loss was seen at 18 months in participants with DS (-5.2%) and non-DS-related IDD (-6.8%), with no difference between groups (P = 0.53). Significant reductions in energy intake were seen across the 18-month intervention in both DS and non-DS-related IDD groups with between-group differences at 12 months only (1119 vs. 1492 kcal/day, respectively; P = 0.003). Although MVPA did not increase in either group across the intervention, those with non-DS-related IDD had higher levels of MVPA compared with those with DS across 18 months.

CONCLUSION

Participants with DS lost a clinically significant amount of weight across the 18-month intervention. Compared with those with non-DS-related IDD, those with DS lost similar amounts of weight, had similar decreases in energy intake and participated in less MVPA across the 18-month intervention. Although individuals with DS have physiological factors that may contribute to obesity, weight management interventions designed for individuals with IDD may be equally effective in this population.

Down syndrome

Trisomy 21, the presence of a supernumerary chromosome 21, results in a collection of clinical features commonly known as Down syndrome (DS). DS is among the most genetically complex of the conditions that are compatible with human survival post-term, and the most frequent survivable autosomal aneuploidy. Mouse models of DS, involving trisomy of all or part of human chromosome 21 or orthologous mouse genomic regions, are providing valuable insights into the contribution of triplicated genes or groups of genes to the many clinical manifestations in DS. This endeavour is challenging, as there are >200 protein-coding genes on chromosome 21 and they can have direct and indirect effects on homeostasis in cells, tissues, organs and systems. Although this complexity poses formidable challenges to understanding the underlying molecular basis for each of the many clinical features of DS, it also provides opportunities for improving understanding of genetic mechanisms underlying the development and function of many cell types, tissues, organs and systems. Since the first description of trisomy 21, we have learned much about intellectual disability and genetic risk factors for congenital heart disease. The lower occurrence of solid tumours in individuals with DS supports the identification of chromosome 21 genes that protect against cancer when overexpressed. The universal occurrence of the histopathology of Alzheimer disease and the high prevalence of dementia in DS are providing insights into the pathology and treatment of Alzheimer disease. Clinical trials to ameliorate intellectual disability in DS signal a new era in which therapeutic interventions based on knowledge of the molecular pathophysiology of DS can now be explored; these efforts provide reasonable hope for the future.

Health comorbidities and cognitive abilities across the lifespan in Down syndrome

BACKGROUND

Down syndrome (DS) is associated with variable intellectual disability and multiple health and psychiatric comorbidities. The impact of such comorbidities on cognitive outcomes is unknown. We aimed to describe patterns of physical health and psychiatric comorbidity prevalence, and receptive language ability, in DS across the lifespan, and determine relationships with cognitive outcomes.

METHODS

Detailed medical histories were collected and cognitive abilities measured using standardised tests for 602 individuals with DS from England and Wales (age range 3 months to 73 years). Differences in prevalence rates between age groups and between males and females were determined using chi-squared or Fisher's exact tests. In adults, rates for psychiatric comorbidities were compared to expected population rates using standardised morbidity ratios (SMRs). Adapted ANCOVA functions were constructed to explore age and sex associations with receptive language ability across the lifespan, and regression analyses were performed to determine whether the presence of health comorbidities or physical phenotypes predicted cognitive abilities.

RESULTS

Multiple comorbidities showed prevalence differences across the lifespan, though there were few sex differences. In adults, SMRs were increased in males and decreased in females with DS for schizophrenia, bipolar disorder, and anxiety. Further, SMRs were increased in both males and females with DS for dementia, autism, ADHD, and depression, with differences more pronounced in females for dementia and autism, and in males for depression. Across the lifespan, receptive language abilities increasingly deviated from age-typical levels, and males scored poorer than females. Only autism and epilepsy were associated with poorer cognitive ability in those aged 16-35 years, with no relationships for physical health comorbidities, including congenital heart defects.

CONCLUSIONS

Our results indicate the prevalence of multiple comorbidities varies across the lifespan in DS, and in adults, rates for psychiatric comorbidities show different patterns for males and females relative to expected population rates. Further, most health comorbidities are not associated with poorer cognitive outcomes in DS, apart from autism and epilepsy. It is essential for clinicians to consider such differences to provide appropriate care and treatment for those with DS and to provide prognostic information relating to cognitive outcomes in those with comorbidities.

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.

Non-invasive Ventilation and CPAP Failure in Children and Indications for Invasive Ventilation

Non-invasive ventilation (NIV) and continuous positive airway pressure (CPAP) are effective treatments for children with severe sleep disordered breathing (SBD). However, some patients may present too severe SDB that do not respond to NIV/CPAP or insufficient compliance to treatment. A careful revaluation of the interface and of ventilator settings should be performed before considering alternative treatments. In patients with obstructive sleep apnea (OSA), alternatives to CPAP/NIV rely on the underlying disease. Ear-nose-throat (ENT) surgery such as adeno-tonsillectomy (AT), turbinectomy or supraglottoplasty represent an effective treatment in selected patients before starting CPAP/NIV and should be reconsidered in case of CPAP failure. Rapid maxillary expansion (RME) is restricted to children with OSA and a narrow palate who have little adenotonsillar tissue, or for those with residual OSA after AT. Weight loss is the first line therapy for obese children with OSA before starting CPAP and should remain a priority in the long-term. Selected patients may benefit from maxillo-facial surgery such as mandibular distraction osteogenesis (MDO) or from neurosurgery procedures like fronto-facial monobloc advancement. Nasopharyngeal airway (NPA) or high flow nasal cannula (HFNC) may constitute efficient alternatives to CPAP in selected patients. Hypoglossal nerve stimulation has been proposed in children with Down syndrome not tolerant to CPAP. Ultimately, tracheostomy represents the unique alternative in case of failure of all the above-mentioned treatments. All these treatments require a multidisciplinary approach with a personalized treatment tailored on the different diseases and sites of obstruction. In patients with neuromuscular, neurological or lung disorders, non-invasive management in case of NIV failure is more challenging. Diaphragmatic pacing has been proposed for some patients with central congenital hypoventilation syndrome (CCHS) or neurological disorders, however its experience in children is limited. Finally, invasive ventilation via tracheotomy represents again the ultimate alternative for children with severe disease and little or no ventilatory autonomy. However, ethical considerations weighting the efficacy against the burden of this treatment should be discussed before choosing this last option.

Emergent high fatality lung disease in systemic juvenile arthritis

OBJECTIVE

To investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA).

METHODS

In a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data.

RESULTS

LD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features.

CONCLUSIONS

A rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

The demographic data and the high frequency of chromosome/chromatid breaks as biomarkers for genome integrity have a role in predicting the susceptibility to have Down syndrome in a cohort of Egyptian young-aged mothers

Background

Down syndrome (DS) is a common numerical chromosome disorder that has its burden on both family and community. The well-known risk factor for chromosome 21 nondisjunction is advanced maternal age which failed to explain the occurrence of Down syndrome born to mothers less than 35 years. This study aimed to assess the effect of demographic data (consanguinity, residency area, and socioeconomic state) and chromosome/chromatid breaks as biomarkers for genome integrity on the susceptibility of young mothers to have a child with Down syndrome.

Results

Fifty mothers with a history of at least one DS pregnancy before the age of 35 were compared to 50 control mothers. There was a significant increase in DS births in consanguineous parents (46%) compared to 20% in non-consanguineous ones (OR = 3.40; 95% CI = 1.4–8.20, P = 0.006). Young mothers with DS children were more likely to be from rural areas (60%) than urban areas (40%) (OR = 2.66; 95%, CI = 1.18–5.98, P = 0.017) and of a low socioeconomic status (62%) rather than a high socioeconomic status (38%) (OR = 3.80; 95%, CI = 1.65–8.74, P = 0.001).

Chromosome/chromatid breaks were detected in 76% of DS young mothers and 32% of control mothers (P < 0.001). There was an odds ratio of chromatid breaks of 8.50 (3.411–21.17) and chromosome breaks of 3.93 (1.40–11.05) with significant difference between the studied groups (P < 0.001 and P = 0.009 respectively).

Conclusion

In addition to advanced maternal age, consanguinity, residency in rural areas, and low socioeconomic status could be considered as possible risk factors for Down syndrome. The high frequency of chromosome/chromatid breaks in young mothers with a previous history of DS children highlights the impact of genome integrity on the tendency to chromosome 21 nondisjunction. These findings are valuable in predicting having a Down syndrome baby and providing proper genetic counseling for high-risk families.

Trisomy 21 dysregulates T cell lineages toward an autoimmunity-prone state associated with interferon hyperactivity

Triplication of human chromosome 21, or trisomy 21 (T21), causes the condition known as Down syndrome (DS). People with DS show a markedly different disease spectrum relative to typical people, being highly predisposed to conditions such as Alzheimer’s disease, while being protected from other conditions, such as most solid malignancies. Interestingly, people with DS are affected by high rates of autoimmune disorders, whereby the immune system mistakenly attacks healthy tissues. This manuscript reports an exhaustive characterization of the T cells of people with DS, demonstrating many alterations in this key immune cell type that could explain their high risk of autoimmunity. These results reveal opportunities for therapeutic intervention to modulate T cell function and improve health outcomes in DS.

Trisomy 21 (T21) causes Down syndrome (DS), a condition characterized by high prevalence of autoimmune disorders. However, the molecular and cellular mechanisms driving this phenotype remain unclear. Building upon our previous finding that T cells from people with DS show increased expression of interferon (IFN)-stimulated genes, we have completed a comprehensive characterization of the peripheral T cell compartment in adults with DS with and without autoimmune conditions. CD8+ T cells from adults with DS are depleted of naïve subsets and enriched for differentiated subsets, express higher levels of markers of activation and senescence (e.g., IFN-γ, Granzyme B, PD-1, KLRG1), and overproduce cytokines tied to autoimmunity (e.g., TNF-α). Conventional CD4+ T cells display increased differentiation, polarization toward the Th1 and Th1/17 states, and overproduction of the autoimmunity-related cytokines IL-17A and IL-22. Plasma cytokine analysis confirms elevation of multiple autoimmunity-related cytokines (e.g., TNF-α, IL17A–D, IL-22) in people with DS, independent of diagnosis of autoimmunity. Although Tregs are more abundant in DS, functional assays show that CD8+ and CD4+ effector T cells with T21 are resistant to Treg-mediated suppression, regardless of Treg karyotype. Transcriptome analysis of white blood cells and T cells reveals strong signatures of T cell differentiation and activation that correlate positively with IFN hyperactivity. Finally, mass cytometry analysis of 8 IFN-inducible phosphoepitopes demonstrates that T cell subsets with T21 show elevated levels of basal IFN signaling and hypersensitivity to IFN-α stimulation. Therefore, these results point to T cell dysregulation associated with IFN hyperactivity as a contributor to autoimmunity in DS.