Autoimmunity and Genetic Syndromes: A Focus on Down Syndrome

Celiac disease in children and adolescents with Down syndrome: behavioural, adaptive and sleep profiles

BACKGROUND

Individuals with Down syndrome (DS) exhibit higher risk for celiac disease (CD) than general population. Although literature suggests CD could be associated with behavioural problems in both paediatric and adult age, such association has been poorly explored in children and adolescents DS. Therefore, the current study aimed to investigate differences in emotional/behavioural difficulties, adaptive skills and sleep problems between children with DS with and without CD.

METHODS

Data were retrospectively collected from a database including data from 381 individuals with DS (3-18 years). The final sample included 65 participants, 27 with co-occurring CD and 38 age, IQ, sex and body mass index-matched controls without CD. Emotional/behavioural difficulties, adaptive skills and sleep problems were assessed through parent report questionnaires.

RESULTS

No group differences emerged in emotional/behavioural difficulties, whereas participants in the CD group showed better adaptive skills in the practical domain than control group. Weak differences emerged in sleep problems.

CONCLUSIONS

Youth with DS and co-occurring CD do not exhibit more emotional and behavioural problems than youth with DS without co-occurring CD but exhibit better adaptive skills in the practical domain.

Intricacies of aging and Down syndrome

Down syndrome is the most frequently occurring genetic condition, with a substantial escalation in risk associated with advanced maternal age. The syndrome is characterized by a diverse range of phenotypes, affecting to some extent all levels of organization, and its progeroid nature - early manifestation of aspects of the senile phenotype. Despite extensive investigations, many aspects and mechanisms of the disease remain unexplored. The current review aims to provide an overview of the main causes and manifestations of Down syndrome, while also examining the phenomenon of accelerated aging and exploring potential therapeutic strategies.

Down Syndrome and Autoimmune Disease

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

Cytokine Storm Syndrome Responsive to IL-1 Inhibition in Trisomy 21

Background

Cytokine storm syndromes (CSS) are life-threatening systemic inflammatory disorders caused by immune system dysregulation. They can lead to organ failure and are triggered by various factors, including infections, malignancy, inborn errors of immunity, and autoimmune conditions. Trisomy 21 (TS21), also known as Down syndrome, is a genetic disorder associated with immune dysfunction, increased infection susceptibility, and inflammation. While TS21 has been linked to infectious-triggered hyperinflammation, its role as a primary cause of CSS has not been confirmed. Case Presentation. We present a case of a 16-year-old male with TS21 with fever, rash, joint pain, and abdominal symptoms. Extensive investigations ruled out infections, autoimmune conditions, malignancies, and inborn errors of immunity as triggers for a CSS. The patient's symptoms improved with treatment using IL-1 inhibition and corticosteroids.

Conclusions

This case reinforces that TS21 is an immune dysregulation disorder and highlights the importance of considering CSS in TS21 patients, even when triggers are unclear. The positive response to IL-1 inhibition in this patient suggests that dysregulation of the IL-1 superfamily and the NLRP3 inflammasome may contribute to CSS in TS21. This finding raises the possibility of using IL-1 inhibition as a treatment approach for CSS in TS21 patients.

Hypovitaminosis D in persons with Down syndrome and autism spectrum disorder

BACKGROUND

Plasma levels of vitamin D have been reported to be low in persons with Down syndrome (DS) and existing data is limited to small and homogenous cohorts. This is of particular importance in persons with DS given the high rates of autoimmune disease in this population and the known relationship between vitamin D and immune function. This study sought to investigate vitamin D status in a multi-center cohort of individuals with DS and compare them to individuals with autism spectrum disorder (ASD) and neurotypical (NT) controls.

METHODS

A retrospective, multi-center review was performed. The three sites were located at latitudes of 42.361145, 37.44466, and 34.05349. Patients were identified by the International Classification of Diseases (ICD)-9 or ICD-10 codes for DS, ASD, or well-child check visits for NT individuals. The first vitamin D 25-OH level recorded in the electronic medical record (EMR) was used in this study as it was felt to be the most reflective of a natural and non-supplemented state. Vitamin D 25-OH levels below 30 ng/mL were considered deficient.

RESULTS

In total, 1624 individuals with DS, 5208 with ASD, and 30,775 NT controls were identified. Individuals with DS had the lowest mean level of vitamin D 25-OH at 20.67 ng/mL, compared to those with ASD (23.48 ng/mL) and NT controls (29.20 ng/mL) (p < 0.001, 95% CI: -8.97 to -6.44). A total of 399 (24.6%) individuals with DS were considered vitamin D deficient compared to 1472 (28.3%) with ASD and 12,397 (40.3%) NT controls (p < 0.001, 95% CI: -5.43 to -2.36). Individuals with DS with higher body mass index (BMI) were found to be more likely to have lower levels of vitamin D (p < 0.001, 95% CI: -0.3849 to -0.1509). Additionally, having both DS and a neurologic diagnosis increased the likelihood of having lower vitamin D levels (p < 0.001, 95% CI: -5.02 to -1.28). Individuals with DS and autoimmune disease were much more likely to have lower vitamin D levels (p < 0.001, 95% CI: -6.22 to -1.55). Similarly, a history of autoimmunity in a first-degree relative also increased the likelihood of having lower levels of vitamin D in persons with DS (p = 0.01, 95% CI: -2.45 to -0.63).

CONCLUSIONS

Individuals with DS were noted to have hypovitaminosis D in comparison to individuals with ASD and NT controls. Associations between vitamin D deficiency and high BMI, personal autoimmunity, and familial autoimmunity were present in individuals with DS.

Pernicious Anemia in an Adult with Trisomy 21

Pernicious anemia is an autoimmune disease caused by the malabsorption of vitamin B12. It usually appears in the elderly. People with trisomy 21 are susceptible to autoimmune diseases. This susceptibility is thought to be due to altered expression of the AIRE gene, which is located in the 21q22.3 region. Although pernicious anemia is not common in people with trisomy 21, AIRE is pointed out as a susceptibility gene of pernicious anemia in a genome-wide association study. Here, we report a man with trisomy 21, who suffered from the pernicious anemia. When he was in his 30 s, he visited our hospital because of diarrhea and poor oral intake. He showed thrombocytopenic purpura-like features, and was diagnosed as pernicious anemia. After supplementation of vitamin B12, he recovered from the illness. The reason for his early onset may be because of trisomy 21. Altered expression of AIRE might trigger the disease.

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.

Down Syndrome Altered Cell Composition in Blood, Brain, and Buccal Swab Samples Profiled by DNA-Methylation-Based Cell-Type Deconvolution

Down syndrome (DS) is a genetic disorder caused by an extra copy of chromosome 21 that presents developmental dysfunction and intellectual disability. To better understand the cellular changes associated with DS, we investigated the cell composition in blood, brain, and buccal swab samples from DS patients and controls using DNA methylation-based cell-type deconvolution. We used genome-scale DNA methylation data from Illumina HumanMethylation450k and HumanMethylationEPIC arrays to profile cell composition and trace fetal lineage cells in blood samples (DS N = 46; control N = 1469), brain samples from various regions (DS N = 71; control N = 101), and buccal swab samples (DS N = 10; control N = 10). In early development, the number of cells from the fetal lineage in the blood is drastically lower in DS patients (Δ = 17.5%), indicating an epigenetically dysregulated maturation process for DS patients. Across sample types, we observed significant alterations in relative cell-type proportions for DS subjects compared with the controls. Cell-type proportion alterations were present in samples from early development and adulthood. Our findings provide insight into DS cellular biology and suggest potential cellular interventional targets for DS.

Celiac disease prevalence and predisposing-HLA in a cohort of 93 Williams-Beuren syndrome patients

Williams-Beuren syndrome is considered to be at increased risk for celiac disease, as for recent literature data and celiac disease guidelines, despite pathogenic mechanisms are still unclear. Our study analyzed the prevalence of autoimmune disorders, HLA DQ2 and/or DQ8 haplotypes, of transglutaminase antibodies and of diagnosis of celiac disease in a cohort of 93 Williams-Beuren syndrome's patients (mean age 21.26 years). Our study showed an increased prevalence of celiac disease equal to 10.8% (10/93 patients). We did not find a significant different frequency of predisposing HLA in subjects with Williams-Beuren syndrome compared to literature data in the general population (49.5% vs. 42.9%, with p > .1), nor a susceptibility to autoimmunity. This suggests that the increased prevalence of celiac disease in Williams-Beuren syndrome cannot be ascribed to HLA haplotype and may be related to other factors that still need to be identified in these patients.

Consequences of chromosome gain: A new view on trisomy syndromes

Chromosome gains are detrimental for the development of the human embryo. As such, autosomal trisomies almost always result in spontaneous abortion, and the rare embryos surviving until live birth suffer from a plethora of pathological defects. There is no treatment currently available to ameliorate the consequences of trisomies, such as Down syndrome (trisomy of chromosome 21). Identifying the source of the phenotypes observed in cells with extra chromosomes is crucial for understanding the underlying molecular causes of trisomy syndromes. Although increased expression of the genes localized on the extra chromosome triggers several pathological phenotypes, an alternative model suggests that global, aneuploidy-associated changes in cellular physiology also contribute to the pathology. Here, we compare the molecular consequences of trisomy syndromes in vivo against engineered cell lines carrying various chromosome gains in vitro. We point out several phenotypes that are shared by variable trisomies and, therefore, might be caused by the presence of an extra chromosome per se, independent of its identity. This alternative view may provide useful insights for understanding Down syndrome pathology and open additional opportunities for diagnostics and treatments.

Altered spontaneous brain activity in Down syndrome and its relation with cognitive outcome

Although Down syndrome (DS) is the most common genetic cause of neurodevelopmental delay, few neuroimaging studies have explored this population. This investigation aimed to study whole-brain resting-state spontaneous brain activity using fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) strategies to find differences in spontaneous brain activity among young people with DS and controls and to correlate these results with cognitive outcomes. The sample comprised 18 persons with DS (age mean = 28.67, standard deviation = 4.18) and 18 controls (age mean = 28.56, standard deviation = 4.26). fALFF and ReHo analyses were performed, and the results were correlated with other cognitive variables also collected (KBIT-2 and verbal fluency test). Increased activity was found in DS using fALFF in areas involving the frontal and temporal lobes and left cerebellum anterior lobe. Decreased activity in DS was found in the left parietal and occipital lobe, the left limbic lobe and the left cerebellum posterior lobe. ReHo analysis showed increased activity in certain DS areas of the left frontal lobe and left rectus, as well as the inferior temporal lobe. The areas with decreased activity in the DS participants were regions of the frontal lobe and the right limbic lobe. Altered fALFF and ReHo were found in the DS population, and this alteration could predict the cognitive abilities of the participants. To our knowledge, this is the first study to explore regional spontaneous brain activity in a population with DS. Moreover, this study suggests the possibility of using fALFF and ReHo as biomarkers of cognitive function, which is highly important given the difficulties in cognitively evaluating this population to assess dementia. More research is needed, however, to demonstrate its utility.

Rebalancing the unbalanced aged immune system - A special focus on zinc

Nowadays, aging is understood as a dynamic and multifaceted dysregulation process that spares almost no human organ or cell. The immune system being among the most affected, it has been shown predominantly that its integrity determines the tightrope walk between the difference of escaping or suffering from age-related diseases. Next to drug-based anti-aging strategies, micronutrient intervention may represent an emerging but less radical way to slow immune aging. While a sufficient supply of a variety of micronutrients is undeniably important, adequate intake of the trace element zinc appears to tower over others in terms of reaching old age. Inconveniently, zinc deficiency prevalence among the elderly is high, which in turn contributes to increased susceptibility to infection, decreased anti-tumor immunity as well as attenuated response to vaccination. Driven by this research, this review aims to provide a comprehensive and up-to-date overview of the various rebalancing capabilities of zinc in the unbalanced immune system of the elderly. This includes an in-depth and cell type-centered discussion on the role of zinc in immunosenescence and inflammaging. We further address upcoming translational aspects e.g. how zinc deficiency promotes the flourishing of certain pathogenic taxa of the gut microbiome and how zinc supply counteracts such alterations in a manner that may contribute to longevity. In the light of the ongoing COVID-19 pandemic, we also briefly review current knowledge on the interdependency between age, zinc status, and respiratory infections. Based on two concrete examples and considering the latest findings in the field we conclude our remarks by outlining tremendous parallels between suboptimal zinc status and accelerated aging on the one hand and an optimized zinc status and successful aging on the other hand.

The Clinical Spectrum of Inflammatory Bowel Disease Associated With Specific Genetic Syndromes: Two Novel Pediatric Cases and a Systematic Review

Background and Aims: Inflammatory bowel disease (IBD) is a typical polygenic disorder and less frequently shows a monogenic origin. Furthermore, IBD can originate in the context of specific genetic syndromes associated with a risk of autoimmune disorders. We aimed to systematically evaluate the prevalence of IBD in specific genetic syndromes and to review the clinical characteristics of the published cases. Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies describing patients with IBD and a genetic syndrome and/or studies indicating the prevalence or incidence of IBD in subjects with a genetic syndrome were included. Results: Forty-six studies describing a total of 67 cases of IBD in six genetic syndromes and two personally assessed unpublished cases were included in the review. The majority of cases were associated with Turner syndrome (TS) (38 cases), Down syndrome (DS) (18 cases) and neurofibromatosis type 1 (NF1) (8 cases). Sporadic cases were described in DiGeorge syndrome (2), Kabuki syndrome (2), and Williams syndrome (1). The prevalence of IBD ranged from 0.67 to 4% in TS and from 0.2 to 1.57% in DS. The incidence of IBD was increased in TS and DS compared to the general population. Eight cases of IBD in TS had a severe/lethal course, many of which described before the year 2000. Two IBD cases in DS were particularly severe. Conclusion: Evidence of a greater prevalence of IBD is accumulating in TS, DS, and NF1. Management of IBD in patients with these genetic conditions should consider the presence of comorbidities and possible drug toxicities. Systematic Review Registration: PROSPERO, identifier: CRD42021249820.