Increased prevalence of Down's syndrome in individuals with type 1 diabetes in Denmark: A nationwide population-based study

IgG1 glycosylation highlights premature aging in Down syndrome

Down syndrome (DS) is characterized by lowered immune competence and premature aging. We previously showed decreased antibody response following SARS-CoV-2 vaccination in adults with DS. IgG1 Fc glycosylation patterns are known to affect the effector function of IgG and are associated with aging. Here, we compare total and anti-spike (S) IgG1 glycosylation patterns following SARS-CoV-2 vaccination in DS and healthy controls (HC). Total and anti-Spike IgG1 Fc N-glycan glycoprofiles were measured in non-exposed adults with DS and controls before and after SARS-CoV-2 vaccination by liquid chromatography-mass spectrometry (LC-MS) of Fc glycopeptides. We recruited N = 44 patients and N = 40 controls. We confirmed IgG glycosylation patterns associated with aging in HC and showed premature aging in DS. In DS, we found decreased galactosylation (50.2% vs. 59.0%) and sialylation (6.7% vs. 8.5%) as well as increased fucosylation (97.0% vs. 94.6%) of total IgG. Both cohorts showed similar bisecting GlcNAc of total and anti-S IgG1 with age. In contrast, anti-S IgG1 of DS and HC showed highly comparable glycosylation profiles 28 days post vaccination. The IgG1 glycoprofile in DS exhibits strong premature aging. The combination of an early decrease in IgG1 Fc galactosylation and sialylation and increase in fucosylation is predicted to reduce complement activity and decrease FcγRIII binding and subsequent activation, respectively. The altered glycosylation patterns, combined with decreased antibody concentrations, help us understand the susceptibility to severe infections in DS. The effect of premature aging highlights the need for individuals with DS to receive tailored vaccines and/or vaccination schedules.

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.

Characterization of autoimmune eye disease in association with Down's syndrome

BACKGROUND

Autoimmunity and deficiency of the transcription factor autoimmune regulator protein (AIRE) are known associations with Down syndrome (DS). Lack of AIRE abrogates thymic tolerance. The autoimmune eye disease associated with DS has not been characterized. We identified a series of subjects with DS (n = 8) and uveitis. In three consecutive subjects, we tested the hypothesis that autoimmunity to retinal antigens might be a contributing factor.

SUBJECTS/METHODS

This was a multicentred, retrospective case series. Deidentified clinical data of subjects with both DS and uveitis were collected via questionnaire by uveitis-trained ophthalmologists. Anti-retinal autoantibodies (AAbs) were detected using an Autoimmune Retinopathy Panel tested in the OHSU Ocular Immunology Laboratory.

RESULTS

We characterized eight subjects (mean age 29 [range, 19-37] years). The mean age of detected uveitis onset was 23.5 [range, 11-33] years. All eight subjects had bilateral uveitis (p < 0.001 based on comparison to published university referral patterns), with anterior and intermediate uveitis found in six and five subjects respectively. Each of three subjects tested for anti-retinal AAbs was positive. Detected AAbs included anti-carbonic anhydrase II, anti-enolase, anti-arrestin, and anti-aldolase.

DISCUSSION

A partial deficiency in the AIRE on chromosome 21 has been described in DS. The similarities in the uveitis presentations within this patient group, the known autoimmune disease predisposition in DS, the recognized association of DS and AIRE deficiency, the reported detection of anti-retinal antibodies in patients with DS in general, and the presence of anti-retinal AAbs in three subjects in our series supports a causal association between DS and autoimmune eye disease.

Integration of ATAC-seq and RNA-seq identifies MX1-mediated AP-1 transcriptional regulation as a therapeutic target for Down syndrome

BACKGROUND

Growing evidence has suggested that Type I Interferon (I-IFN) plays a potential role in the pathogenesis of Down Syndrome (DS). This work investigates the underlying function of MX1, an effector gene of I-IFN, in DS-associated transcriptional regulation and phenotypic modulation.

METHODS

We performed assay for transposase-accessible chromatin with high-throughout sequencing (ATAC-seq) to explore the difference of chromatin accessibility between DS derived amniocytes (DSACs) and controls. We then combined the annotated differentially expressed genes (DEGs) and enriched transcriptional factors (TFs) targeting the promoter region from ATAC-seq results with the DEGs in RNA-seq, to identify key genes and pathways involved in alterations of biological processes and pathways in DS.

RESULTS

Binding motif analysis showed a significant increase in chromatin accessibility of genes related to neural cell function, among others, in DSACs, which is primarily regulated by members of the activator protein-1 (AP-1) transcriptional factor family. Further studies indicated that MX Dynamin Like GTPase 1 (MX1), defined as one of the key effector genes of I-IFN, is a critical upstream regulator. Its overexpression induced expression of AP-1 TFs and mediated inflammatory response, thus leading to decreased cellular viability of DS cells. Moreover, treatment with specific AP-1 inhibitor T-5224 improved DS-associated phenotypes in DSACs.

CONCLUSIONS

This study demonstrates that MX1-mediated AP-1 activation is partially responsible for cellular dysfunction of DS. T-5224 effectively ameliorated DS-associated phenotypes in DSACs, suggesting it as a potential treatment option for DS patients.

A Scoping Review of the Complementary Feeding Practices and Early Eating Experiences of Children With Down Syndrome

OBJECTIVE

Children with Down syndrome may experience more challenges in their early feeding and may be introduced to complementary foods comparatively later than typically developing (TD) children. This scoping review aimed to identify and synthesize the existing literature that describes feeding problems and early eating experiences relating to the period of complementary feeding for children with Down syndrome.

METHODS

Scopus, PubMed, Medline, Web of Science, and PsycInfo were searched. Journal articles published between January 1991 and June 2022 that reported on the complementary feeding period with children with Down syndrome were included.

RESULTS

Eighteen journal articles met the inclusion criteria. Children with Down syndrome were introduced to complementary foods later than TD children and progressed to more challenging food textures at a slower rate. Gross and fine motor skill delays and sensory difficulties contributed to secondary feeding problems such as difficulties chewing, biting, and reduced awareness of food on lips and tongue. Parents of children with Down syndrome reported exercising more caution and employing more controlling feeding practices compared to TD and had higher levels of concern regarding their child's weight.

CONCLUSIONS

Guidelines and early feeding support specific to children with Down syndrome should be available before the first complementary foods are introduced and throughout this period. Feeding support should aim to address parental concerns and provide assistance when feeding problems occur, to minimize delays and encourage the optimum development of eating abilities. Future research should address the development of feeding problems during this period and explore possible interventions.

Acquired cardiovascular disease in adults with congenital heart disease

Rates of successful surgical repair and life expectancy for patients with congenital heart disease have increased dramatically in recent decades. Thanks to advances in diagnosis, treatment, and follow-up care, an ever-increasing number of individuals with congenital heart disease are reaching advanced age. The exposure to cardiovascular risk factors during their lifetime is modifying the outlook and late clinical trajectory of adult congenital heart disease (ACHD). Their disease burden is shifting from congenital to acquired, primarily atherosclerotic cardiovascular disease (ASCVD) with worrisome consequences. In addition, the complex background of ACHD often curbs appropriate preventive strategies by general practitioners or adult cardiologists. Comprehensive guidance for the prevention and management of acquired heart disease in ACHD patients is currently not available, as this topic has not been covered by the European Society of Cardiology (ESC) guidelines on cardiovascular disease prevention or the ESC guidelines for the management of ACHD. In this document, a state-of-the-art overview of acquired heart disease in ACHD patients and guidance on ASCVD prevention for both ACHD specialists and non-ACHD cardiologists are provided. The aim is to provide a clinical consensus statement to foster the development of a sustainable strategy for the prevention of ASCVD in a practical and simple-to-follow way in this ever-growing cardiovascular cohort, thus reducing their cardiovascular burden.

Characterization of autoimmune eye disease in association with Down's Syndrome

Background Autoimmunity and deficiency of the transcription factor autoimmune regulator protein (AIRE) are known associations with Down Syndrome (DS). Lack of AIRE abrogates thymic tolerance. The autoimmune eye disease associated with DS has not been characterized. We identified a series of subjects with DS (n = 8) and uveitis. In 3 consecutive subjects, we tested the hypothesis that autoimmunity to retinal antigens might be a contributing factor. Subjects/Methods: This was a multicentered, retrospective case series. De-identified clinical data of subjects with both DS and uveitis were collected via questionnaire by uveitis-trained ophthalmologists. Anti-retinal autoantibodies (AAbs) were detected using an Autoimmune Retinopathy Panel tested in the OHSU Ocular Immunology Laboratory. Results We characterized 8 subjects (mean age 29 [range, 19-37] years). The mean age of uveitis onset was 23.5 [range, 11-33] years. All 8 subjects had bilateral uveitis (p < 0.001 based on comparison to published university referral patterns), with anterior and intermediate uveitis found in 6 and 5 subjects respectively. Each of three subjects tested for anti-retinal AAbs was positive. Detected AAbs included anti-carbonic anhydrase II, anti-enolase, anti-arrestin, and anti-aldolase. Discussion A partial deficiency in the AIRE on chromosome 21 has been described in DS. The similarities in the uveitis presentations within this patient group, the known autoimmune disease predisposition in DS, the recognized association of DS and AIRE deficiency, the reported detection of anti-retinal antibodies in patients with DS in general, and the presence of anti-retinal AAbs in 3 subjects in our series supports a causal association between DS and autoimmune eye disease.

Prescriptions for insulin and insulin analogues in children with and without major congenital anomalies: a data linkage cohort study across six European regions

Are children with major congenital anomalies more likely to develop diabetes requiring insulin therapy, as indicated by prescriptions for insulin, than children without congenital anomalies? The aim of this study is to evaluate prescription rates of insulin/insulin analogues in children aged 0-9 years with and without major congenital anomalies. A EUROlinkCAT data linkage cohort study, involving six population-based congenital anomaly registries in five countries. Data on children with major congenital anomalies (60,662) and children without congenital anomalies (1,722,912), the reference group, were linked to prescription records. Birth cohort and gestational age were examined. The mean follow-up for all children was 6.2 years. In children with congenital anomalies aged 0-3 years, 0.04 per 100 child-years (95% CIs 0.01-0.07) had > 1 prescription for insulin/insulin analogues compared with 0.03 (95% CIs 0.01-0.06) in reference children, increasing ten-fold by age 8-9 years. The risk of > 1 prescription for insulin/insulin analogues aged 0-9 years in children with non-chromosomal anomalies (RR 0.92, 95% CI 0.84-1.00) was similar to that of reference children. However, children with chromosomal anomalies (RR 2.37, 95% CI 1.91-2.96), and specifically children with Down syndrome (RR 3.44, 95% CIs 2.70-4.37), Down syndrome with congenital heart defects (RR 3.86, 95% CIs 2.88-5.16) and Down syndrome without congenital heart defects (RR 2.78, 95% CIs 1.82-4.27), had a significantly increased risk of > 1 prescription for insulin/insulin analogues aged 0-9 years compared to reference children. Female children had a reduced risk of > 1 prescription aged 0-9 years compared with male children (RR 0.76, 95% CI 0.64-0.90 for children with congenital anomalies and RR 0.90, 95% CI 0.87-0.93 for reference children). Children without congenital anomalies born preterm (< 37 weeks) were more likely to have > 1 insulin/insulin analogue prescription compared to term births (RR 1.28, 95% CIs 1.20-1.36).

CONCLUSION

This is the first population-based study using a standardised methodology across multiple countries. Males, children without congenital anomalies born preterm and those with chromosomal anomalies had an increased risk of being prescribed insulin/insulin analogues. These results will help clinicians to identify which congenital anomalies are associated with an increased risk of developing diabetes requiring insulin therapy and allow them to reassure families of children who have non-chromosomal anomalies that their risk is similar to that of the general population.

WHAT IS KNOWN

• Children and young adults with Down syndrome have an increased risk of diabetes requiring insulin therapy. • Children born prematurely have an increased risk of developing diabetes requiring insulin therapy.

WHAT IS NEW

• Children with non-chromosomal anomalies do not have an increased risk of developing diabetes requiring insulin therapy compared to children without congenital anomalies. • Female children, with or without major congenital anomalies, are less likely to develop diabetes requiring insulin therapy before the age of 10 compared to male children.

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.

Association between perinatal factors and future risk for gout-a nested case-control study

Background

Increased level of urate is the strongest risk factor for gout development but since only a minority of hyperuricemics are affected by gout, other pathogenic factors must be considered. Low birth weight is associated with future morbidities causing hyperuricemia, such as diabetes and renal disease. The purpose of this study was to investigate if, and to what extent, maternal and perinatal factors, including birth weight, are associated with future risk of being diagnosed with gout.

Methods

A population-based retrospective nested case-control registry study based on regional and national health care registers in Sweden. All incident cases of gout born in 1973 and onward who had received ≥1 diagnosis of gout from 2000 through 2019 in the region of western Sweden were included. Up to 5 non-gout controls were matched to each case by age, sex, and county at the year of first gout diagnosis. A range of maternal, gestational, and perinatal factors were analyzed for their potential association to future gout development. This included the health of the mother, gestational length, birth weight, number of siblings, and congenital malformations.

Results

Maternal diabetes, any congenital malformation, and being small for gestational age were factors that significantly increased the risk for future gout development, odds ratio (95% CI) 3.1 (1.3 to 7.4) (p=0.01), 1.33 (1.04 to 1.7) (p=0.02), and 1.75 (1.3 to 2.3) (p<.0001), respectively.

Conclusions

In this study, maternal diabetes and being small for gestational age increased the risk for future gout development in young adults. As of today, these conditions are becoming more prevalent and may contribute to the ongoing gout epidemic. These results require both confirmation and further delineation of underlying mechanisms.

Characteristics of type 1 diabetes mellitus in children and adolescents with Down's syndrome in an admixed population

OBJECTIVE

People with Down's syndrome (DS) have a higher risk of developing type 1 diabetes mellitus (T1D) and may have specific clinical features compared to T1D patients without DS. This study evaluated the clinical and laboratory aspects of T1D in children and adolescents with DS in an admixed population.

METHODS

A case-control study comparing patients with T1D and DS (T1D+DS) to patients with T1D without DS (T1D controls) from two tertiary academic Hospitals in São Paulo, Brazil.

RESULTS

The sample consisted of 9 patients with T1D+DS and 18 T1D age and sex-matched controls. Anti-glutamic acid decarboxylase 65 antibodies were positive in 7/7 of the 9 T1D+DS patients, confirming the presence of diabetes autoimmunity in this group. Mean age at diagnosis of T1D was 4.9 ± 3.9 years in the T1D+DS group and 6.4 years ± 3 in the T1D control group; early diagnosis (<2 years old) occurred in three T1D+DS patients but only in one T1D control patients, both suggesting lower age of diagnosis in T1D+DS group, although without statistical significance (p = 0.282 and p = 0.093, respectively). The T1D+DS group presented lower total insulin dose (0.7 IU/kg/day ± 0.2) and HbA1c (7.2% ± 0.6) than the control group (1.0 IU/kg/day ± 0.3 and 9.1% ± 0.7, respectively) (p = 0.022 and p = 0.047, respectively).

CONCLUSION

We confirmed the autoimmune etiology of diabetes in people with DS in this admixed population. T1D+DS patients developed diabetes earlier and achieved better metabolic control with a lower insulin dose than T1D controls. These findings are in agreement with previous studies in Caucasian populations.

Interferon-Driven Immune Dysregulation in Down Syndrome: A Review of the Evidence

Down syndrome (DS) is a unique genetic disease caused by the presence of an extra copy of chromosome 21, which carries four of the six interferon receptor (IFN-R) genes on its long arm. Recent studies reporting higher levels of interferon-stimulated gene (ISG) expression in primary immune cells studied ex vivo have suggested that the additional copies of the IFN-R genes in DS result in mild interferonopathy. In this review, we analyze the potential clinical and immunological impacts of this interferonopathy in DS. We performed a literature review to explore the epidemiology and risks of celiac disease, type 1 diabetes, thyroid dysfunction, mucocutaneous manifestations, infectious diseases (including COVID-19), and Alzheimer’s disease in individuals with DS relative to the general population with or without iatrogenic exposure to interferons. We analyzed immunophenotyping data and the current experimental evidence concerning IFN-R expression, constitutive JAK-STAT activation, and ISG overexpression in DS. Despite the lack of direct evidence that implicating this mild interferonopathy directly in illnesses in individuals with DS, we highlight the challenges ahead and directions that could be taken to determine more clearly the biological impact of interferonopathy on various immune-related conditions in DS.

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.

Genetic syndromes with diabetes: A systematic review

Previous reviews and clinical guidelines have identified 10-20 genetic syndromes associated with diabetes, but no systematic review has been conducted to date. We provide the first comprehensive catalog for syndromes with diabetes mellitus. We conducted a systematic review of MEDLINE, Embase, CENTRAL, PubMed, OMIM, and Orphanet databases for case reports, case series, and observational studies published between 1946 and January 15, 2020, that described diabetes mellitus in adults and children with monogenic or chromosomal syndromes. Our literature search identified 7,122 studies, of which 160 fulfilled inclusion criteria. Our analysis of these studies found 69 distinct diabetes syndromes. Thirty (43.5%) syndromes included diabetes mellitus as a cardinal clinical feature, and 56 (81.2%) were fully genetically elucidated. Sixty-three syndromes (91.3%) were described more than once in independent case reports, of which 59 (93.7%) demonstrated clinical heterogeneity. Syndromes associated with diabetes mellitus are more numerous and diverse than previously anticipated. While knowledge of the syndromes is limited by their low prevalence, future reviews will be needed as more cases are identified. The genetic etiologies of these syndromes are well elucidated and provide potential avenues for future gene identification efforts, aid in diagnosis and management, gene therapy research, and developing personalized medicine treatments.

Medical vulnerability of individuals with Down syndrome to severe COVID-19-data from the Trisomy 21 Research Society and the UK ISARIC4C survey

BACKGROUND

Health conditions, immune dysfunction, and premature aging associated with trisomy 21 (Down syndrome, DS) may impact the clinical course of COVID-19.

METHODS

The T21RS COVID-19 Initiative launched an international survey for clinicians or caregivers on patients with COVID-19 and DS. Data collected between April and October 2020 (N=1046) were analysed and compared with the UK ISARIC4C survey of hospitalized COVID-19 patients with and without DS.

FINDINGS

The mean age of COVID-19 patients with DS in the T21RS survey was 29 years (SD = 18). Similar to the general population, the most frequent signs and symptoms of COVID-19 were fever, cough, and shortness of breath. Joint/muscle pain and vomiting or nausea were less frequent (p < 0.01), whereas altered consciousness/confusion were more frequent (p < 0.01). Risk factors for hospitalization and mortality were similar to the general population with the addition of congenital heart defects as a risk factor for hospitalization. Mortality rates showed a rapid increase from age 40 and were higher in patients with DS (T21RS DS versus non-DS patients: risk ratio (RR) = 3.5 (95%-CI=2.6;4.4), ISARIC4C DS versus non-DS patients: RR = 2.9 (95%-CI=2.1;3.8)) even after adjusting for known risk factors for COVID-19 mortality.

INTERPRETATION

Leading signs/symptoms of COVID-19 and risk factors for severe disease course are similar to the general population. However, individuals with DS present significantly higher rates of medical complications and mortality, especially from age 40.

FUNDING

Down Syndrome Affiliates in Action, DSMIG-USA, GiGi's Playhouse, Jerome Lejeune Foundation, LuMind IDSC Foundation, The Matthew Foundation, NDSS, National Task Group on Intellectual Disabilities and Dementia Practices.

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.

Stress Responses in Down Syndrome Neurodegeneration: State of the Art and Therapeutic Molecules

Down syndrome (DS) is the most common genomic disorder characterized by the increased incidence of developing early Alzheimer’s disease (AD). In DS, the triplication of genes on chromosome 21 is intimately associated with the increase of AD pathological hallmarks and with the development of brain redox imbalance and aberrant proteostasis. Increasing evidence has recently shown that oxidative stress (OS), associated with mitochondrial dysfunction and with the failure of antioxidant responses (e.g., SOD1 and Nrf2), is an early signature of DS, promoting protein oxidation and the formation of toxic protein aggregates. In turn, systems involved in the surveillance of protein synthesis/folding/degradation mechanisms, such as the integrated stress response (ISR), the unfolded stress response (UPR), and autophagy, are impaired in DS, thus exacerbating brain damage. A number of pre-clinical and clinical studies have been applied to the context of DS with the aim of rescuing redox balance and proteostasis by boosting the antioxidant response and/or inducing the mechanisms of protein re-folding and clearance, and at final of reducing cognitive decline. So far, such therapeutic approaches demonstrated their efficacy in reverting several aspects of DS phenotype in murine models, however, additional studies aimed to translate these approaches in clinical practice are still needed.

An international survey on the impact of COVID-19 in individuals with Down syndrome

BACKGROUND

Health conditions and immune dysfunction associated with trisomy 21 (Down syndrome, DS) may impact the clinical course of COVID-19 once infected by SARS-CoV-2.

METHODS

The T21RS COVID-19 Initiative launched an international survey for clinicians or caregivers/family members on patients with COVID-19 and DS (N=1046). De-identified survey data collected between April and October 2020 were analysed and compared with the UK ISARIC4C survey of hospitalized COVID-19 patients with and without DS. COVID-19 patients with DS from the ISARIC4C survey (ISARIC4C DS cases=100) were matched to a random set of patients without DS (ISARIC4C controls=400) and hospitalized DS cases in the T21RS survey (T21RS DS cases=100) based on age, gender, and ethnicity.

FINDING

The mean age in the T21RS survey was 29 years (SD=18), 73% lived with their family. Similar to the general population, the most frequent signs and symptoms of COVID-19 were fever, cough, and shortness of breath. Pain and nausea were reported less frequently (p<0.01), whereas altered consciousness/confusion were reported more frequently (p<0.01). Risk factors for hospitalization and mortality were similar to the general population (age, male gender, diabetes, obesity, dementia) with the addition of congenital heart defects as a risk factor for hospitalization. Mortality rates showed a rapid increase from age 40 and were higher than for controls (T21RS DS versus controls: risk ratio (RR)=3.5 (95%-CI=2.6;4.4), ISARIC4C DS versus controls: RR=2.9 (95%-CI=2.1;3.8)) even after adjusting for known risk factors for COVID-19 mortality.

INTERPRETATION

Leading signs/symptoms of COVID-19 and risk factors for severe disease course are similar to the general population. However, individuals with DS present significantly higher rates of mortality, especially from age 40.

FUNDING

Down Syndrome Affiliates in Action, Down Syndrome Medical Interest Group-USA, GiGi's Playhouse, Jerome Lejeune Foundation, LuMind IDSC Foundation, Matthews Foundation, National Down Syndrome Society, National Task Group on Intellectual Disabilities and Dementia Practices.

Early Onset of Autoimmune Diabetes in Children with Down Syndrome-Two Separate Aetiologies or an Immune System Pre-Programmed for Autoimmunity?

PURPOSE OF REVIEW

An increased frequency of autoimmunity in children with Down syndrome (DS) is well described but few studies have investigated the underlying mechanisms. Recent immune system investigation of individuals with DS may shed light on the increased risk of autoimmune conditions including type 1 diabetes.

RECENT FINDINGS

Diagnosis of type 1 diabetes is accelerated in children with DS with 17% diagnosed at, or under, the age of 2 years compared with only 4% in the same age group in the general population. Counterintuitively, children with DS and diabetes have less human leukocyte antigen (HLA)-mediated susceptibility than age-matched children with autoimmune diabetes from the general population. Early onset of diabetes in DS is further highlighted by the recent description of neonatal cases of diabetes which is autoimmune but not HLA associated. There are two potential explanations for this accelerated onset: (1) an additional chromosome 21 increases the genetic and immunological risk of autoimmune diabetes or (2) there are two separate aetiologies in children with DS and diabetes. Autoimmunity in DS is an under-investigated area. In this review, we will draw on recent mechanistic studies in individuals with DS which shed some light on the increased risk of autoimmunity in children with DS and consider the current support for and against two aetiologies underlying diabetes in children with DS.

Evaluation of biochemical and hematological parameters in adults with Down syndrome

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

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.

Multiorgan involvement and management in children with Down syndrome

AIM

To review multiorgan involvement and management in children with Down syndrome (DS).

METHODS

A literature review of articles from 1980 to 2019 using the MEDLINE interface of PubMed was performed using the following search terms- [Down syndrome] or [Trisomy 21] AND [Cardiology] or [Respiratory] or [neurodevelopment] or [epilepsy] or [musculoskeletal] or [immune system] or [haematological] or [endocrine] or [gastrointestinal] or [ophthalmological] or [Ear Nose Throat] or [dermatology] or [renal].

RESULTS

Congenital heart disease particularly septal defects occur in over 60% of infants with DS and 5%-34% of infants develop persistent pulmonary hypertension of the newborn irrespective of a diagnosis of congenital heart disease. Early recognition and management of aspiration, obstructive sleep apnoea and recurrent lower respiratory tract infections (LRTI) could reduce risk of developing pulmonary hypertension in later childhood. Children with DS have an increased risk of autistic spectrum disorder, attention deficit disorder and epilepsy particularly infantile spasms, which are associated with poor neurodevelopmental outcomes. Congenital anomalies of the gastrointestinal and renal system as well as autoimmune diseases, coeliac disease, arthropathy, thyroid dysfunction fold diabetes mellitus and dermatological conditions are more common. Hearing and visual anomalies are also well recognised association with DS (Table 1).

CONCLUSION

Children with DS are at an increased risk of multiorgan comorbidities. Organ-specific health surveillance may provide holistic care for the children and families with DS throughout childhood.

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.

Illustration of tessellation in Down syndrome

Background: Tessellated fundus refers to a specific change in the appearance of the internal layers of the eye in which the choroidal large vessels became visible through polygonal hypopigmented areas. Such hypopigmented areas alternate with hyperpigmented zones in a tigroid pattern. Fundus tessellation is often associated with myopia and choroidal thinning.Materials and Methods: We analyzed fundus images from 50 children with Down syndrome and 52 controls.Results: Tessellation was present in 64% of children with Down syndrome, compared with only 13.5% of controls (p < .0001). In most cases, tessellation was located peripapillary, and no difference was observed in tessellation localization between children with Down syndrome and controls (p = .60). Although more prevalent in myopic children with and without Down syndrome, tessellation was present in almost half (48%) of children with Down syndrome with hyperopia versus only 5% of controls with the same refractive status.Conclusions: Mechanical stretching of the choroid could explain the high rate of tessellation in myopes. Other factors must contribute to the higher prevalence of tessellated fundus in children with Down syndrome without myopia. We discuss potentially relevant factors and propose vascular involvement as a contributor to tessellation in our population with Down syndrome. Further studies assessing choroidal vasculature in individuals with Down syndrome are needed to confirm this theory.

Clinical implications of immune-mediated diseases in children with Down syndrome

Children with Down syndrome have changes in their innate and adaptive immunity, which contribute to increased rates of infections, autoimmune diseases, and haematological malignancies. While improved care for congenital heart disease has decreased mortality and morbidity, complications related to immune-mediated diseases continue to limit the life expectancy in Down syndrome. Infectious diseases are common and have a significant effect on development, behaviour and quality of life. Infection frequency and severity are influenced by various anatomical and physiological alterations in addition to immunological changes in Down syndrome. Thus, prevention of respiratory tract infections requires a multifactorial approach. This could include additional active and/or passive immunizations, prophylactic antibiotics, immunoglobulin replacement and ear, nose and throat surgical interventions. Autoimmune conditions like coeliac disease, type I diabetes mellitus and thyroid disease are classically mentioned in the context of Down syndrome. However, autoinflammatory conditions are more prevalent as well. Screening for autoimmune diseases is required and immunosuppression has to be used with caution. Future studies should address optimal screening programmes for immune-mediated diseases in individuals with Down syndrome, as well as the effect of immune modulation, to further decrease morbidity and mortality, and improve the quality of life of individuals with Down syndrome.

Cardiometabolic Risk and Body Composition in Youth With Down Syndrome

BACKGROUND AND OBJECTIVES

Whether BMI captures adiposity and cardiometabolic risk in Down syndrome (DS), a condition associated with obesity, short stature, and altered body proportions, is not known. We compared cardiometabolic risk measures in youth with DS and typically developing matched controls.

METHODS

Youth with (n = 150) and without (n = 103) DS of comparable age (10-20 years), sex, race, ethnicity, and BMI percentile underwent whole-body dual-energy X-ray absorptiometry, fasting glucose, insulin, lipids, lipoprotein particles, inflammatory factors, and when BMI percentile ≥85, an oral glucose tolerance test.

RESULTS

Sixty-four percent of youth with DS had BMI percentile ≥85. Among these, no difference in glucose, insulin, or insulin resistance was detected, but prediabetes was more prevalent with DS (26.4% vs 10.3%; P = .025) after adjustment for demographics, pubertal status, and BMI z score (odds ratio = 3.2; P = .026). Among all participants, those with DS had higher low-density lipoprotein cholesterol (median 107 [interquartile range 89-128] vs 88.5 [79-103] mg/dL; P < .00005), triglycerides (89.5 [73-133] vs 71.5 [56-104] mg/dL; P < .00005), non-high-density lipoprotein cholesterol (non-HDL-C; 128 [104-153] vs 107 [92-123] mg/dL; P < .00005), and triglycerides/HDL-C (2.2 [1.6-3.4] vs 1.7 [1.1-2.5] mg/dL; P = .0003) and lower levels of HDL-C (41 [36.5-47] vs 45 [37-53] mg/dL; P = .012). DS youth had higher high-sensitivity C-reactive protein, interleukin-6, small low-density lipoprotein particles (LDL-P), and total LDL-P, but similar LDL-P size. Youth with DS had less visceral fat (VFAT), fat mass, and lean mass for BMI z score, but greater VFAT at higher fat mass. However, VFAT did not fully explain the increased prevalence of dyslipidemia or prediabetes in youth with DS.

CONCLUSIONS

Despite similar insulin resistance, youth with DS had greater prevalence of dyslipidemia and prediabetes than typically developing youth, which was not fully explained by VFAT.

Trisomy 21 Is a Cause of Permanent Neonatal Diabetes That Is Autoimmune but Not HLA Associated

Identifying new causes of permanent neonatal diabetes (PNDM) (diagnosis <6 months) provides important insights into β-cell biology. Patients with Down syndrome (DS) resulting from trisomy 21 are four times more likely to have childhood diabetes with an intermediate HLA association. It is not known whether DS can cause PNDM. We found that trisomy 21 was seven times more likely in our PNDM cohort than in the population (13 of 1,522 = 85 of 10,000 observed vs. 12.6 of 10,000 expected) and none of the 13 DS-PNDM patients had a mutation in the known PNDM genes that explained 82.9% of non-DS PNDM. Islet autoantibodies were present in 4 of 9 DS-PNDM patients, but DS-PNDM was not associated with polygenic susceptibility to type 1 diabetes (T1D). We conclude that trisomy 21 is a cause of autoimmune PNDM that is not HLA associated. We propose that autoimmune diabetes in DS is heterogeneous and includes coincidental T1D that is HLA associated and diabetes caused by trisomy 21 that is not HLA associated.

‘I will never be old’: adults with Down syndrome and their parents talk about ageing-related challenges

The life expectancy of people with Down syndrome (DS) has increased significantly over the last few decades. Consequently, they and their families face new ageing-related challenges, the first signs of which appear in people with DS around the age of 30. The goal of this study was to explore the perceptions of adults with DS regarding their own and their parents’ ageing and end of life, and to examine the views and concerns of the parents regarding the ageing of their children with DS. The unique approach used in our study was to convene not only the ageing people with DS but also their parents, to discuss the subject together. A total of 33 people with DS participated in the study. Most of them were interviewed with one or two parents. Participants with DS found it difficult to talk about their own old age and addressed the issue mainly through the decline in the functioning of an older person they knew. The parents emphasised the changes needed in terms of the official regulations, so as to ensure that their children with DS age with dignity and quality of life. Our study identifies the increasingly pressing need to prepare adults with DS for their own and their parents’ ageing and end of life in a timely manner.

The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health

This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.

Pediatric endocrinology through syndromes

In everyday practice, a pediatric endocrinologist will face a variety of different endocrine issues (such as short or tall stature, dysthyroidism, abnormal pubertal timing or impaired glucose metabolism), which relevantly contribute to the global care of a number of syndromic conditions. On the other hand, the presence of endocrine features may assist in the diagnostic process, leading to final diagnosis of a syndromic disorder. The intention of this review is to provide a referenced overview of different genetic syndromes characterized by endocrine features, and to present a possible classification, based on whether the endocrinopathy or the syndrome is typically recognized first. Thus, the first part of the manuscript deals with the most common syndromes associated with endocrine dysfunctions, while the second part describes the conditions by which a syndrome is most frequently diagnosed after an endocrine finding. The aim is to provide a practical overview of the assessment of syndromic patients, so that they can be recognized and managed in an integrated, multidisciplinary fashion.

Pediatric diabetic ketoacidosis in a patient with Down syndrome. Case report

Introduction:. Patients with Down syndrome (DS) have an increased risk of developing autoimmune diseases. This is a rare case of a pediatric patient with DS with an initial clinical profile of diabetic ketoacidosis.Case presentation:. 6-year-old male patient with symptoms suggestive of diabetes mellitus type 1 (DM1) of 15 days of evolution (polyuria, polydipsia, polyphagia and loss of 2 kilos of weight), who was admitted to the emergency department of the Hospital de San José, in Bogotá, Colombia, with uncontrollable vomiting and dehydration. The tests performed confirmed moderate ketoacidosis: glycometry: 592 mg/dL, pH: 7.19, HCO3: 10 mmol/L, PCO2: 45, PO2: 95 and lactic acid: 1.4 mmol/L. Management with isotonic fluids and intravenous insulin therapy was initiated and the patient was transferred to the pediatric intensive care unit, where ketoacidosis was controlled in approximately 10 hours. Subcutaneous insulin schedule was initiated without complications.Discussion:. This case highlights the importance of monitoring possible autoimmune complications in patients with DS, since the risk of developing them is 4.2 times higher than in the general population.Conclusion:. This case calls on to contemplate autoimmune complications in patients with DS during clinical practice. Although they are not part of the most frequent reasons for consultation, they cannot be underestimated and should be suspected and treated in a timely manner.

Occurrence of Hypothyroidism, Diabetes Mellitus, and Celiac Disease in Emirati Children with Down's Syndrome

Objectives

Autoimmune diseases are known to occur in people with Down's syndrome (DS), especially celiac disease, type 1 diabetes mellitus (DM), and hypothyroidism. Since there are common genetic risk factors involved in the occurrence of these autoimmune disorders, the risks would differ in different populations. We sought to determine the prevalence of type 1 DM, celiac disease, and hypothyroidism in Emirati patients with DS in Abu Dhabi, UAE.

Methods

Ninety-two patients with DS were investigated for the presence of anti-thyroid antibodies, antithyroglobulin, and anti-thyroid peroxidase antibodies for hypothyroidism, anti-glutamic acid decarboxylase antibodies for type 1 DM, and anti-tissue transglutaminase immunoglobulin A antibodies for celiac disease.

Results

Karyotyping was performed on 89 patients. Eighty-seven had non-disjunction of chromosome 21 (97.8%), one was a mosaic, and one had translocation. Of the patients studied, 19.6% had hypothyroidism, 4.3% had type 1 DM, and 1.1% had celiac disease. Out of the 92 patients studied, 66 (71.7%) did not have any autoimmune disease, 25 (27.2%) had one autoimmune disease, and one (1.1%) had two autoimmune diseases.

Conclusions

Celiac disease was the least prevalent autoimmune disease in patients with DS patients, while type 1 DM and hypothyroidism were both significantly associated with DS.

High prevalence of diabetes mellitus, hypertension and obesity among persons with a recorded diagnosis of intellectual disability or autism spectrum disorder

BACKGROUND

Obesity and lack of physical activity are frequently reported in persons with intellectual disability (ID) or autism spectrum disorder (ASD). We hypothesised a higher prevalence of diabetes and hypertension in this population.

METHOD

We used administrative data for all primary and specialist outpatient and inpatient healthcare consultations for people with at least one recorded diagnosis of diabetes mellitus, hypertension or obesity from 1998 to 2015. Data were drawn from the central administrative database for Stockholm County, Sweden. It was not possible to separate data for type 1 and type 2 diabetes. We stratified 26 988 individuals with IDs or ASD into three groups, with Down syndrome treated separately, and compared these groups with 1 996 140 people from the general population.

RESULTS

Compared with the general population, men and women with ID/ASD had 1.6-3.4-fold higher age-adjusted odds of having a registered diagnosis of obesity or diabetes mellitus, with the exception of diabetes among men with Down syndrome. A registered diagnosis of hypertension was only more common among men with ID/ASD than in the general population.

CONCLUSIONS

Diabetes and blood pressure health screening, along with efforts to prevent development of obesity already in childhood, are necessary for individuals with IDs and ASD. We believe that there is a need for adapted community-based health promotion programmes to ensure more equitable health for these populations.

CA1 pyramidal neuron gene expression mosaics in the Ts65Dn murine model of Down syndrome and Alzheimer's disease following maternal choline supplementation

Although there are changes in gene expression and alterations in neuronal density and afferent inputs in the forebrain of trisomic mouse models of Down syndrome (DS) and Alzheimer's disease (AD), there is a lack of systematic assessments of gene expression and encoded proteins within individual vulnerable cell populations, precluding translational investigations at the molecular and cellular level. Further, no effective treatment exists to combat intellectual disability and basal forebrain cholinergic neurodegeneration seen in DS. To further our understanding of gene expression changes before and following cholinergic degeneration in a well-established mouse model of DS/AD, the Ts65Dn mouse, we assessed RNA expression levels from CA1 pyramidal neurons at two adult ages (∼6 months of age and ∼11 months of age) in both Ts65Dn and their normal disomic (2N) littermates. We further examined a therapeutic intervention, maternal choline supplementation (MCS), which has been previously shown to lessen dysfunction in spatial cognition and attention, and have protective effects on the survival of basal forebrain cholinergic neurons in the Ts65Dn mouse model. Results indicate that MCS normalized expression of several genes in key gene ontology categories, including synaptic plasticity, calcium signaling, and AD-associated neurodegeneration related to amyloid-beta peptide (Aβ) clearance. Specifically, normalized expression levels were found for endothelin converting enzyme-2 (Ece2), insulin degrading enzyme (Ide), Dyrk1a, and calcium/calmodulin-dependent protein kinase II (Camk2a), among other relevant genes. Single population expression profiling of vulnerable CA1 pyramidal neurons indicates that MCS is a viable therapeutic for long-term reprogramming of key transcripts involved in neuronal signaling that are dysregulated in the trisomic mouse brain which have translational potential for DS and AD.

What people with Down Syndrome can teach us about cardiopulmonary disease

Down syndrome is the most common chromosomal abnormality among live-born infants. Through full or partial trisomy of chromosome 21, Down syndrome is associated with cognitive impairment, congenital malformations (particularly cardiovascular) and dysmorphic features. Immune disturbances in Down syndrome account for an enormous disease burden ranging from quality-of-life issues (autoimmune alopecia) to more serious health issues (autoimmune thyroiditis) and life-threatening issues (leukaemia, respiratory tract infections and pulmonary hypertension). Cardiovascular and pulmonary diseases account for ∼75% of the mortality seen in persons with Down syndrome. This review summarises the cardiovascular, respiratory and immune challenges faced by individuals with Down syndrome, and the genetic underpinnings of their pathobiology. We strongly advocate increased comparative studies of cardiopulmonary disease in persons with and without Down syndrome, as we believe these will lead to new strategies to prevent and treat diseases affecting millions of people worldwide.

The role of key workers in supporting people with intellectual disability in the self-management of their diabetes: a qualitative New Zealand study

The incidence of diabetes in people with an intellectual disability, although unknown, is indicated to be higher than the general population. Given the challenges individuals with intellectual disability may face, this population is often dependent upon key workers to manage their health and well-being. One aim of a wider study on the self-management of diabetes by people with intellectual disability was to explore how key workers supported their self-management. That aim was the focus of this paper. Between 2009 and 2010, 17 staff from five residential intellectual disability services and two supported independent living services within New Zealand, consented to a semi-structured interview. Transcripts of the interviews were analysed using Thomas' General Inductive Approach. Three overarching themes emerged; having knowledge and understanding, being lifestyle police and ensuring future well-being. While knowledge, skills and perspectives varied, all participants were committed to ensuring that the lifestyle of the person concerned was compatible with the management of their diabetes. A range of perspectives existed between the expectations they had of themselves, colleagues and the individual with diabetes. There was an identified need for initial and ongoing education of permanent and casual staff and the people themselves with diabetes in collaboration with health and disability services to build confidence and promote self-management practices. In so doing, the impacts of this long-term condition may be reduced and the health outcomes improved for people with intellectual disability.

A Syntenic Cross Species Aneuploidy Genetic Screen Links RCAN1 Expression to β-Cell Mitochondrial Dysfunction in Type 2 Diabetes

Type 2 diabetes (T2D) is a complex metabolic disease associated with obesity, insulin resistance and hypoinsulinemia due to pancreatic β-cell dysfunction. Reduced mitochondrial function is thought to be central to β-cell dysfunction. Mitochondrial dysfunction and reduced insulin secretion are also observed in β-cells of humans with the most common human genetic disorder, Down syndrome (DS, Trisomy 21). To identify regions of chromosome 21 that may be associated with perturbed glucose homeostasis we profiled the glycaemic status of different DS mouse models. The Ts65Dn and Dp16 DS mouse lines were hyperglycemic, while Tc1 and Ts1Rhr mice were not, providing us with a region of chromosome 21 containing genes that cause hyperglycemia. We then examined whether any of these genes were upregulated in a set of ~5,000 gene expression changes we had identified in a large gene expression analysis of human T2D β-cells. This approach produced a single gene, RCAN1, as a candidate gene linking hyperglycemia and functional changes in T2D β-cells. Further investigations demonstrated that RCAN1 methylation is reduced in human T2D islets at multiple sites, correlating with increased expression. RCAN1 protein expression was also increased in db/db mouse islets and in human and mouse islets exposed to high glucose. Mice overexpressing RCAN1 had reduced in vivo glucose-stimulated insulin secretion and their β-cells displayed mitochondrial dysfunction including hyperpolarised membrane potential, reduced oxidative phosphorylation and low ATP production. This lack of β-cell ATP had functional consequences by negatively affecting both glucose-stimulated membrane depolarisation and ATP-dependent insulin granule exocytosis. Thus, from amongst the myriad of gene expression changes occurring in T2D β-cells where we had little knowledge of which changes cause β-cell dysfunction, we applied a trisomy 21 screening approach which linked RCAN1 to β-cell mitochondrial dysfunction in T2D.

Inhibition of DYRK1A and GSK3B induces human β-cell proliferation

Insufficient pancreatic β-cell mass or function results in diabetes mellitus. While significant progress has been made in regulating insulin secretion from β-cells in diabetic patients, no pharmacological agents have been described that increase β-cell replication in humans. Here we report aminopyrazine compounds that stimulate robust β-cell proliferation in adult primary islets, most likely as a result of combined inhibition of DYRK1A and GSK3B. Aminopyrazine-treated human islets retain functionality in vitro and after transplantation into diabetic mice. Oral dosing of these compounds in diabetic mice induces β-cell proliferation, increases β-cell mass and insulin content, and improves glycaemic control. Biochemical, genetic and cell biology data point to Dyrk1a as the key molecular target. This study supports the feasibility of treating diabetes with an oral therapy to restore β-cell mass, and highlights a tractable pathway for future drug discovery efforts.

A cross-sectional study of the phenotypes of obesity and insulin resistance in adults with down syndrome

BACKGROUND

Despite the confluence of multiple cardiovascular risk factors, subclinical atherosclerotic damage and cardiovascular events remain extremely rare in adults with Down syndrome (DS). We aim to determine the prevalence of obesity and metabolic disorders in an adult cohort with DS and to compare our findings with adults without DS.

METHODS

Cross-sectional study of 51 consecutively selected adults with DS living in the community and 51 healthy controls in an outpatient clinic of a tertiary care hospital in Madrid, Spain. Epidemiological data (age and gender), anthropometric data (body mass index and waist-to-height ratio), coexisting clinical conditions, and laboratory data (fasting glucose, insulin, glycated hemoglobin, creatinine, thyroid hormones, vitamins, and lipid profile) were measured and compared between the groups.

RESULTS

Adults with DS were significantly younger and more often men with a higher prevalence of overweight and obesity than controls. Their waist-to-height ratio was higher, and they more frequently had abdominal obesity. The results of an analysis adjusted for age and gender revealed no differences in fasting insulin levels, homeostatic model assessment indexes, or lipid profile between adults with DS and controls.

CONCLUSION

Adults with DS presented a high prevalence of overweight and obesity. However, we found no differences in lipid profile, prevalence of insulin resistance, or metabolic syndrome between adults with DS and controls.

Evaluation of the impact of abdominal obesity on glucose and lipid metabolism disorders in adults with Down syndrome

We aimed to describe anthropometric differences in weight-related disorders between adults with Down syndrome (DS) and healthy controls, as well as their disparate impact on glucose and lipid metabolism disorders. We underwent a cross-sectional study of 49 consecutively selected, community-residing adults with DS and 49 healthy controls in an outpatient clinic of a tertiary care hospital in Madrid, Spain. Siblings of adults with DS were studied as controls in 42 cases. Epidemiological data (age and gender), anthropometric data (body mass index, waist circumference, and waist-to-height ratio [WHR]), coexisting clinical conditions, and laboratory data (fasting glucose, insulin, glycated hemoglobin, creatinine, thyroid hormones, and lipid profile) were measured and compared between the groups. Adults with DS were significantly younger and more often male, with a higher prevalence of overweight and obesity than controls. Adults with DS also had a higher WHR, and more frequently presented abdominal obesity. Moreover, insulin resistance measured using the homeostatic model assessment was more prevalent among adults with DS and abdominal obesity. However, lipid profiles were similar between groups. The kappa correlation index for the diagnosis of abdominal obesity between waist circumference and WHR was 0.24 (95%CI: 0.13-0.34). We concluded that the prevalence of overweight, obesity, and abdominal obesity was higher in adults with DS than in controls. Adults with DS and abdominal obesity showed higher indexes of insulin resistance than their non-obese peers. WHR was a useful tool for the evaluation of abdominal obesity in this population.

Unraveling the complexity of neurodegeneration in brains of subjects with Down syndrome: insights from proteomics

Down syndrome (DS) is one of the most common genetic causes of intellectual disability characterized by multiple pathological phenotypes, among which neurodegeneration is a key feature. The neuropathology of DS is complex and likely results from impaired mitochondrial function, increased oxidative stress, and altered proteostasis. After the age of 40 years, many (most) DS individuals develop a type of dementia that closely resembles that of Alzheimer's disease with deposition of senile plaques and neurofibrillary tangles. A number of studies demonstrated that increased oxidative damage, accumulation of damaged/misfolded protein aggregates, and dysfunction of intracellular degradative systems are critical events in the neurodegenerative processes. This review summarizes the current knowledge that demonstrates a “chronic” condition of oxidative stress in DS pointing to the putative molecular pathways that could contribute to accelerate cognition and memory decline. Proteomics and redox proteomics studies are powerful tools to unravel the complexity of DS phenotypes, by allowing to identifying protein expression changes and oxidative PTMs that are proved to be detrimental for protein function. It is reasonable to suggest that changes in the cellular redox status in DS neurons, early from the fetal period, could provide a fertile environment upon which increased aging favors neurodegeneration. Thus, after a critical age, DS neuropathology can be considered a human model of early Alzheimer's disease and could contribute to understanding the overlapping mechanisms that lead from normal aging to development of dementia.

Diabetes in people with an intellectual disability: a systematic review of prevalence, incidence and impact

AIMS

To establish the prevalence and incidence of type 1 and type 2 diabetes in people with an intellectual and developmental disability and determine their impact on health and well-being and to appraise the evidence available to inform good practice in diabetes management for people with intellectual and developmental disabilities.

METHODS

We conducted separate searches of multiple databases (EMBASE, CINAHL, MEDLINE, PsycINFO, SCOPUS, Web of Science, PUBMED and Cochrane Library) to find relevant articles.

RESULTS

A total of 13 studies were identified: 13 addressed the prevalence of diabetes in people with intellectual and developmental disability, three addressed the impact of diabetes on their health and well-being and three addressed the management of diabetes. The prevalence of diabetes in people with intellectual and developmental disability remains uncertain, and the incidence of diabetes in this group of people is unknown. There is some evidence to support the assertion that people with intellectual and developmental disability might be at greater risk of diabetes than the general population. Overall, the quality of the evidence on which to base prevention and management strategies is variable.

CONCLUSIONS

There is a paucity of research focusing on the prevalence, incidence and impact of diabetes among people with intellectual and developmental disability. Further research is needed to inform policy and practice in this area and, in particular, work is needed to develop methodologies, evaluation tools, educational resources and diabetes care support services appropriate to the needs of people with intellectual and developmental disability.

Health conditions and their impact among adolescents and young adults with Down syndrome

Objective

To examine the prevalence of medical conditions and use of health services among young adults with Down syndrome and describe the impact of these conditions upon their lives.

Methods

Using questionnaire data collected in 2011 from parents of young adults with Down syndrome we investigated the medical conditions experienced by their children in the previous 12 months. Univariate, linear and logistic regression analyses were performed.

Results

We found that in addition to the conditions commonly experienced by children with Down syndrome, including eye and vision problems (affecting 73%), ear and hearing problems (affecting 45%), cardiac (affecting 25%) and respiratory problems (affecting 36%), conditions also found to be prevalent within our young adult cohort included musculoskeletal conditions (affecting 61%), body weight (affecting 57%), skin (affecting 56%) and mental health (affecting 32%) conditions and among young women menstrual conditions (affecting 58%). Few parents reported that these conditions had no impact, with common impacts related to restrictions in opportunities to participate in employment and community leisure activities for the young people, as well as safety concerns.

Conclusion

There is the need to monitor, screen and provide appropriate strategies such as through the promotion of healthy lifestyles to prevent the development of comorbidities in young people with Down syndrome and, where present, to reduce their impact.

A community cross-sectional survey of medical problems in 440 children with Down syndrome in New York State

OBJECTIVE

To determine the frequency of medical problems in a large population of children with Down syndrome.

STUDY DESIGN

Study population included 440 children with Down syndrome (ages 3-14 years) identified primarily through the New York Congenital Malformations Registry. Parents completed questionnaires on medical problems.

RESULTS

Our study population was predominately White (92.3%), non-Hispanic (72.3%) with at least 1 college educated parent (72.3%). The prevalence of medical problems was as follows: heart disease (55%), hearing problem (39%), vision problem (39%), thyroid disease (27%), celiac disease (5%), alopecia (5%), seizures (7%), asthma/reactive airway disease (32%), diabetes (1%), and juvenile rheumatoid arthritis (0.2%). Of the children with heart disease, 58% needed surgery at a mean age of 9 months. Of the children with hearing loss, 29% were identified on newborn screening and 13% used an amplification device. Of the children with thyroid disease, 31% were diagnosed in the newborn period. Only 7% of these children with Down syndrome had no medical problem listed.

CONCLUSION

Prevalence data of medical illnesses in a large population of children with Down syndrome provide us with data to support implementation of the American Academy of Pediatrics guidelines for health supervision for children with Down syndrome. The long-term health implications of the conditions we surveyed will be important for decreasing morbidity and increasing overall health and wellness into adulthood.

Type 2 diabetes mellitus: An unusual association with Down's syndrome

Down's syndrome (DS) is known to be associated with autoimmune disease including type 1 diabetes. To the best of our knowledge, there are no reports of DS with type 2 diabetes mellitus in the literature. We hereby report two cases of DS with type 2 diabetes.

The impact of hyperglycemia on risk of infection and early death during induction therapy for acute lymphoblastic leukemia (ALL)

Hyperglycemia during induction chemotherapy for childhood acute lymphoblastic leukemia (ALL) has been inconsistently associated with risk of infection. We investigated the incidence of hyperglycemia during induction for childhood ALL in a retrospective cohort study of 144 patients treated on a single national protocol (UKALL2003) and explored its association with infection. All patients received dexamethasone. Overt hyperglycemia was seen in 36% and proven bacterial or fungal infection was most common in this group (OR 4.1 (1.1-15.6), P = 0.039). Both hyperglycaemia and infection were particularly common in patients with Down Syndrome.