Down syndrome: Cognitive and behavioral functioning across the lifespan

Differential microRNA expression profile in blood of children with Down syndrome suggests a role in immunological dysfunction

Down syndrome (DS), caused by trisomy of chromosome 21 (HSA21), results in a broad range of phenotypes. However, the determinants contributing to the complex and variable phenotypic expression of DS are still not fully known. Changes in microRNAs (miRNAs), short non-coding RNA molecules that regulate gene expression post-transcriptionally, have been associated with some DS phenotypes. Here, we investigated the genome-wide mature miRNA expression profile in peripheral blood mononuclear cells (PBMCs) of children with DS and controls and identified biological processes and pathways relevant to the DS pathogenesis. The expression of 754 mature miRNAs was profiled in PBMCs from six children with DS and six controls by RT-qPCR using TaqMan^® Array Human MicroRNA Cards. Functions and signaling pathways analyses were performed using DIANA-miRPath v.3 and DIANA-microT-CDS software. Children with DS presented six differentially expressed miRNAs (DEmiRs): four overexpressed (miR-378a-3p, miR-130b-5p, miR-942-5p, and miR-424-3p) and two downregulated (miR-452-5p and miR-668-3p). HSA21-derived miRNAs investigated were not found to be differentially expressed between the groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed potential target genes involved in biological processes and pathways pertinent to immune response, e.g., toll-like receptors (TLRs) signaling, Hippo, and transforming growth factor β (TGF-β) signaling pathways. These results suggest that altered miRNA expression could be contributing to the well-known immunological dysfunction observed in individuals with DS.

Reading and Listening Comprehension in Individuals With Down Syndrome and Word Reading-Matched Typically Developing Children

PURPOSE

The purpose of this study was to explore the reading comprehension and listening comprehension performance of English-speaking children with Down syndrome (DS) compared with word reading-matched typically developing (TD) children.

METHOD

Participants included 19 individuals with DS (M _age = 17;2 [years;months], range: 11;1-22;9) and 19 word reading-matched TD children (M _age = 7;2, range: 6;6-8;1). Participants completed three norm-referenced measures of reading comprehension and three norm-referenced measures of listening comprehension. Dependent variables were raw scores on each measure, with the exception of scaled scores on one reading comprehension measure.

RESULTS

Independent-samples t tests with Bonferroni-adjusted alpha levels of .008 revealed a significant between-groups difference for two of three reading comprehension measures. The mean raw scores were lower for the DS group than the TD group, with large effect sizes. Independent-samples t tests with Bonferroni-adjusted alpha levels of .008 revealed a significant between-groups difference for three of three listening comprehension measures. The mean raw scores on the three measures were lower for the DS group than the TD group, with large effect sizes.

CONCLUSIONS

The DS group, despite being matched on word reading to the TD group, demonstrated reduced reading comprehension skills as compared with the TD group. Thus, as individuals with DS acquire word reading skills, it appears that they are unable to translate word reading success to achieve reading comprehension at the expected level (i.e., as indexed by typical readers). The between-groups differences in listening comprehension suggest that deficits in listening comprehension likely are a barrier to reading comprehension proficiency for children with DS. Listening comprehension may be a malleable factor that can be targeted to improve reading comprehension outcomes for individuals with DS.

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

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

Prenatal and Postnatal Pharmacotherapy in Down Syndrome: The Search to Prevent or Ameliorate Neurodevelopmental and Neurodegenerative Disorders

Those with Down syndrome (DS)-trisomy for chromosome 21-are routinely impacted by cognitive dysfunction and behavioral challenges in children and adults and Alzheimer's disease in older adults. No proven treatments specifically address these cognitive or behavioral changes. However, advances in the establishment of rodent models and human cell models promise to support development of such treatments. A research agenda that emphasizes the identification of overexpressed genes that contribute demonstrably to abnormalities in cognition and behavior in model systems constitutes a rational next step. Normalizing expression of such genes may usher in an era of successful treatments applicable across the life span for those with DS.

Associations of Motor Performance and Executive Functions: Comparing Children with Down Syndrome to Chronological and Mental Age-Matched Controls

Background. Children with Down syndrome (DS) exhibit lower motor and cognitive performance than typically developing children (TD). Although there is a relationship between these two developmental domains, only a few studies have addressed this association in children with DS compared to groups of the same chronological age (CA) or mental age (MA) within one study. This study aimed to fill this research gap. Method and Procedures. The Movement Assessment Battery for Children-2 and the Trail-Making Test was used to assess motor and cognitive performances in 12 children (M = 10.5 ± 10.08) with DS, 12 CA-matched, and 12 MA-matched controls. Results. There are significant group differences in the motor dimension (total test score; p < 0.001, η²_p = 0.734), for processing speed (p < 0.001, η²_p = 0.396), and cognitive flexibility (p < 0.001, η²_p = 0.498). Between TD-CA and both other groups, the differences in the magnitude of correlations for the motor dimension balance are also significant (compared to DS: z = −2.489; p = 0.006, and to TD-MA: z = −3.12; p < 0.001). Conclusions. Our results suggest that the relationships depend on the studied cognitive and motor skills. It seems crucial to select a wide range of tasks for both domains that are as isolated as possible for future studies, to better understand the relationships between cognitive and motor skills in children with DS.

Experientially based narrative instruction: A neurocognitive perspective

BACKGROUND

The purpose of this study was to evaluate the feasibility of a personal narrative intervention based on neurocognitive principles and experientially based learning for improving the personal narrative language abilities of a school-age child with Down's syndrome.

METHOD

A single-case design using contemporary statistical techniques was employed to complete this study. The participant was 8 years 8 months at the time of the study and he participated in a 14-week personal narrative intervention. Personal narrative samples were collected at the beginning of each intervention session prior to instruction. Narrative samples were scored for narrative quality, language productivity, and lexical diversity.

RESULTS

As a result of the intervention, the participant demonstrated moderate-significant increases in narrative abilities for narrative quality, language productivity, and lexical diversity.

CONCLUSIONS

The use of a personal narrative based on neurocognitive principles and experientially based learning may be feasible for improving the personal narrative language abilities of school-age children with Down's syndrome.

Executive functions and adaptive behaviour in individuals with Down syndrome

BACKGROUND

Previous research has explored executive functions (EFs) and adaptive behaviour in children and adolescents with Down syndrome (DS), but there is a paucity of research on the relationship between the two in this population. This study aims to shed light on the profile of EFs and adaptive behaviour in DS, exploring the differences by age and investigating the relationship between these two domains.

METHOD

Parents/caregivers of 100 individuals with DS from 3 to 16 years old participated in the study. The sample was divided into preschoolers (3-6.11 years old) and school-age children (7-16 years old). Parents/caregivers completed either the Preschool Version of the Behaviour Rating Inventory of Executive Function (for children 2-6.11 years old) or the Second Edition of the same Inventory (for individuals 7 + years old). Adaptive behaviour was assessed with the Vineland Adaptive Behaviour Scale - Interview, Second Edition.

RESULTS

Findings suggest that individuals with DS have overall difficulties, but also patterns of strength and weakness in their EFs and adaptive behaviour. The preschool-age and school-age children's EF profiles differed slightly. While both age groups showed Emotional Control as a relative strength and Working Memory as a weakness, the school-age group revealed further weaknesses in Shift and Plan/Organise. As concerns adaptive behaviour, the profiles were similar in the two age groups, with Socialisation as a strength, and Communication and Daily Living Skills as weaknesses, but with a tendency for preschoolers to obtain intermediate scores for the latter. When the relationship between EFs and adaptive behaviour was explored, Working Memory predicted Communication in the younger group, while in the older group the predictors varied, depending on the adaptive domains: Working Memory was a predictor of Communication, Inhibit of Daily Living Skills, and Inhibit and Shift of Socialisation.

CONCLUSION

As well as elucidating the EF profiles and adaptive behaviour in individuals with DS by age, this study points to the role of EFs in adaptive functioning, providing important information for targeted interventions.

Language and executive functioning in young adults with Down syndrome

BACKGROUND

This study examined the association between executive functioning and language in young adults with Down syndrome (DS).

METHOD

Nineteen young adults with DS (aged 19-24 years) completed standardised measures of overall cognition, vocabulary, verbal fluency and executive function skills.

RESULTS

Friedman's analysis of variance (χ² (3) = 28.15, P < .001) and post hoc comparisons indicated that, on average, participants had a significantly lower overall non-verbal than verbal cognitive age equivalent and lower expressive than receptive vocabulary skills. Using Spearman correlations, performance on a verbal measure of cognition inhibition was significantly negatively related to receptive vocabulary (ρ = -.529, adjusted P = .036) and verbal fluency (ρ = -.608, adjusted P = .022). Attention was significantly positively correlated with receptive (ρ = .698, adjusted-p = .005) and expressive (ρ = .542, adjusted P = .027) vocabulary. Verbal working memory was significantly positively associated with receptive vocabulary (ρ = .585, adjusted P = .022) and verbal fluency (ρ = .737, adjusted P = .003). Finally, visuospatial working memory was significantly associated with receptive vocabulary (ρ = .562, adjusted P = .027).

CONCLUSIONS

Verbal and non-verbal measures of executive functioning skills had important associations with language ability in young adults with DS. Future translational research is needed to investigate causal pathways underlying these relationships. Research should explore if interventions aimed at increasing executive functioning skills (e.g. attention, inhibition and working memory) have the potential to lead to increases in language for young adults with DS.

Parental perspectives on the quality of life of children with Down syndrome

Down Syndrome (DS) is the most common chromosome abnormality and the most frequent cause of developmental delay/intellectual disabilities in children. Although the investigation of the quality of life (QoL) is crucial in children with DS, relatively poor attention has been paid to this topic. The current study aimed to evaluate parent-reported QoL in a group of children with DS and identify children's individual and clinical features associated with different levels of QoL. We included in the study 73 children with DS (5-12 years) and investigated the parent-reported levels of QoL by means of the Pediatric Quality of Life Inventory. Cognitive level and the presence of behavioral difficulties were also evaluated. The overall parent-reported QoL of children with DS was high; emotional functioning was the domain with the highest level of QoL. Moreover, parents perceived low levels of QoL in children who exhibited low IQ, worse analogical reasoning, worse adaptive skills, more frequent challenging behaviors, more ritualistic/sameness behavior and more autistic symptoms. No differences emerged for family variables, namely parental education and employment, between the two groups with high and low QoL, as perceived by parents. The understanding of cognitive and behavioral factors - such as analogical reasoning, socio-communication abilities and challenging behaviors - related with different degrees of QoL in children with DS is crucial for the development of effective strategies to promote the improvement of the QoL.

Developmental trajectories of spatial-sequential and spatial-simultaneous working memory in Down syndrome

BACKGROUND

Working memory (WM) is generally considered an area of weakness in the cognitive profile associated with Down syndrome (DS). The great majority of studies explored WM in this population through a comparison with typical development (TD) on the basis of mental age or developmental level. However, it is also relevant to understand how these skills develop and whether such development could be more related to chronological or developmental level. In the present study, we explored cross-sectional developmental trajectories of spatial-sequential and spatial-simultaneous WM in individuals with DS across chronological age and developmental level. Typically developing children (TD) of similar mental age were also included as a comparison group.

METHODS

Eighty-four individuals with DS (aged between 7 and 30 years) and 327 children with TD (aged between 4 and 8 years) were administered with tasks to assess spatial-sequential and spatial-simultaneous WM, together with tasks to assess both general verbal and spatial developmental levels.

RESULTS AND CONCLUSION

Performance in spatial-simultaneous WM task was lower compared with spatial-sequential WM task in both groups. In the case of individuals with DS, the developmental trajectories of chronological age are better described through a segmented model showing increased performance until approximately 13 years of age, followed by a rather flat progress. In the case of TD children, developmental trajectories are better described through a linear model in the spatial-simultaneous WM task when chronological age is considered; in the spatial-sequential WM, the increase in performance with age was however characterised by a discontinuity at age 6. The increase in performance followed a linear pattern in both groups (DS and TD) without substantial differences between the types of measure used (verbal vs. spatial) when the developmental level is considered.

Development of Down Syndrome Research Over the Last Decades-What Healthcare and Education Professionals Need to Know

Down syndrome (DS) is the most prevalent neurodevelopmental disorder, with a known genetic cause. Besides facial dysmorphologies and congenital and/or acquired medical conditions, the syndrome is characterized by intellectual disability, accelerated aging, and an increased likelihood of an early onset Alzheimer's disease in adulthood. These common patterns of DS are derived from the long-held standard in the field of DS research, that describes individuals with DS as a homogeneous group and compares phenotypic outcomes with either neurotypical controls or other neurodevelopmental disorders. This traditional view has changed, as modern research pinpoints a broad variability in both the occurrence and severity of symptoms across DS, arguing for DS heterogeneity and against a single "DS profile." Nevertheless, prenatal counseling does not often prioritize the awareness of potential within-group variations of DS, portraying only a vague picture of the developmental outcomes of children with DS to expectant parents. This mini-review provides a concise update on existent information about the heterogeneity of DS from a full-spectrum developmental perspective, within an interdisciplinary context. Knowledge on DS heterogeneity will not only enable professionals to enhance the quality of prenatal counseling, but also help parents to set targeted early interventions, to further optimize daily functions and the quality of life of their children.

Psychomotor development in infants and young children with Down syndrome-A prospective, repeated measure, post-hoc analysis

Children with Down syndrome (DS) show delayed acquisition of cognitive and functional skills compared to typically developing children. The objective of this study was to accurately describe early development of infants and young children (children hereafter) with DS based on a large recent sample. We carried out repeated measure analysis of the global development quotient (GDQ) and developmental age using data from the Assessment of Systematic Treatment with Folinic Acid and Thyroid Hormone on Psychomotor Development of Down Syndrome Young Children (ACTHYF) study (NCT01576705). Because there was no statistically significant difference in the primary endpoint between active treatment and placebo, data from all treatment groups were pooled for post-hoc analysis. Data of 141 children with DS aged 6-18 months at inclusion were analyzed. Mean GDQ decreased over the study period, especially in the youngest age classes ([6-9] and [9-12] months), indicating that acquisition of skills occurred at a slower pace compared to typically developing children. Strongest deficits were observed for motor and hearing and language skills. Only GDQ at baseline correlated significantly with evolution of GDQ. Future studies should aim at elucidating the mechanisms underlying motor and language development. Early pharmacological interventions together with early childhood therapies might be necessary to improve the developmental trajectory of children with DS.

Educational experiences of pupils with Down syndrome in the UK

BACKGROUND

Though research has identified that increasing numbers of pupils with Down syndrome (DS) in the UK are educated in mainstream schools, little detailed information about the educational experiences of pupils with DS is available.

AIMS

This study explored parent views of the educational experiences of pupils with DS attending UK schools (Reception-Year 11) using an online survey.

METHODS AND PROCEDURES

Responses from 569 parents were collected.

OUTCOMES AND RESULTS

Overall, 65 % of pupils were in mainstream schools but this was more common at primary (80 %) than secondary school (37 %). Pupils participated in most academic and social activities alongside their peers but were commonly not accessing all opportunities. Many pupils received additional support in school including external professional services. Frequent meetings between parents and teachers/teaching assistants indicated high levels of collaboration. Teachers and teaching assistants were largely viewed as responsible for children's learning. Overall, respondents reported satisfaction with provision.

CONCLUSIONS AND IMPLICATIONS

Many pupils with DS in the UK are able to access a broad and balanced curriculum but this is not the case for all. Ways in which provision can be enhanced are discussed.

Modifiable personal and environmental factors associated with anxiety in family caregivers of children with disabilities: A comparison between parents and grandparents

BACKGROUND

Caregivers of children with disabilities might face high risk of anxiety, but the specific influencing factors may be different between parents and grandparents. This study is to explore the influencing modifiable factors from personal and environmental dimensions, so as to provide practical reference for effectively preventing and alleviating anxiety of this population.

METHODS

A total of 504 primary caregivers were investigated in Shanghai, China, of which 496 parents and grandparents were included in the analysis. Risk of anxiety was measured by the Generalized Anxiety Disorder 7-item (GAD-7) Scale. Descriptive statistics, univariate analysis, and multivariable logistic regression were performed to describe the personal and environmental characteristics of parents and grandparents, risk of anxiety, and identify the significant factors.

RESULTS

35.1% of the total caregivers had the risk of anxiety, parents (35.8%) were slightly more anxious than grandparents (33.1%). Among parents, children's stable emotion (AOR=0.263, 95% CI=0.113, 0.611), higher household income (AOR=0.664; 95% CI=0.519, 0.850), owning a house (AOR=0.326; 95% CI=0.174, 0.610), and better barrier-free construction (AOR=0.400; 95% CI=0.170, 0.941) were associated with lower odds of anxiety. As for grandparents, significant association was merely found in caregiving time (AOR=2.936; 95% CI=1.064, 8.107).

LIMITATIONS

Given the cross-sectional design, we would not infer causal relationships.

CONCLUSIONS

Anxiety among family caregivers of children with disabilities was not encouraging and need to be urgently concerned. To reach optimal efficiency, intergenerational differences should be considered when health care providers and policy makers taking measures to facilitate the mental health of this population.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Dermatologic conditions in Down syndrome

Down syndrome (DS) is the most common chromosomal condition and affects many organs including the skin. Dermatologists are an integral part of the DS care team. This is a review of both common and rare dermatologic conditions in DS. We provide practical strategies for a successful dermatology interview and examination. We explore the downstream effects of trisomy of chromosome 21, in particular on the immune system, and how these insights may enhance our pathophysiologic understanding of their cutaneous conditions.

Neurodevelopmental outcome of patients with congenital gastrointestinal malformations: a systematic review and meta-analysis

AIM

Children with congenital gastrointestinal malformations may be at risk of neurodevelopmental impairment due to challenges to the developing brain, including perioperative haemodynamic changes, exposure to anaesthetics and postoperative inflammatory influences. This study aggregates existing evidence on neurodevelopmental outcome in these patients using meta-analysis.

METHOD

PubMed, Embase and Web of Science were searched for peer-reviewed articles published until October 2019. Out of the 5316 unique articles that were identified, 47 studies met the inclusion criteria and were included. Standardised mean differences (Cohen's d) between cognitive, motor and language outcome of patients with congenital gastrointestinal malformations and normative data (39 studies) or the studies' control group (8 studies) were aggregated across studies using random-effects meta-analysis. The value of (clinical) moderators was studied using meta-regression and diagnostic subgroups were compared.

RESULTS

The 47 included studies encompassed 62 cohorts, representing 2312 patients. Children with congenital gastrointestinal malformations had small-sized cognitive impairment (d=-0.435, p<0.001; 95% CI -0.567 to -0.302), medium-sized motor impairment (d=-0.610, p<0.001; 95% CI -0.769 to -0.451) and medium-sized language impairment (d=-0.670, p<0.001; 95% CI -0.914 to -0.425). Patients with short bowel syndrome had worse motor outcome. Neurodevelopmental outcome was related to the number of surgeries and length of total hospital stay, while no relations were observed with gestational age, birth weight, age and sex.

INTERPRETATION

This study shows that children with congenital gastrointestinal malformations exhibit impairments in neurodevelopmental outcome, highlighting the need for routine screening of neurodevelopment during follow-up.

Trisomy of Human Chromosome 21 Orthologs Mapping to Mouse Chromosome 10 Cause Age and Sex-Specific Learning Differences: Relevance to Down Syndrome

Down syndrome (DS), trisomy of human chromosome 21 (Hsa21), is the most common genetic cause of intellectual disability. The Dp10(1)Yey (Dp10) is a mouse model of DS that is trisomic for orthologs of 25% of the Hsa21 protein-coding genes, the entirety of the Hsa21 syntenic region on mouse chromosome 10. Trisomic genes include several involved in brain development and function, two that modify and regulate the activities of sex hormones, and two that produce sex-specific phenotypes as null mutants. These last four are the only Hsa21 genes with known sexually dimorphic properties. Relatively little is known about the potential contributions to the DS phenotype of segmental trisomy of Mmu10 orthologs. Here, we have tested separate cohorts of female and male Dp10 mice, at 3 and 9 months of age, in an open field elevated zero maze, rotarod, and balance beam, plus the learning and memory tasks, spontaneous alternation, puzzle box, double-H maze, context fear conditioning, and acoustic startle/prepulse inhibition, that depend upon the function of the prefrontal cortex, striatum, hippocampus, and cerebellum. We show that there are age and sex-specific differences in strengths and weaknesses, suggesting that genes within the telomere proximal region of Hsa21 influence the DS phenotype.

Aging with Down Syndrome-Where Are We Now and Where Are We Going?

Down syndrome (DS) is a form of accelerated aging, and people with DS are highly prone to aging-related conditions that include vascular and neurological disorders. Due to the overexpression of several genes on Chromosome 21, for example genes encoding amyloid precursor protein (APP), superoxide dismutase (SOD), and some of the interferon receptors, those with DS exhibit significant accumulation of amyloid, phospho-tau, oxidative stress, neuronal loss, and neuroinflammation in the brain as they age. In this review, we will summarize the major strides in this research field that have been made in the last few decades, as well as discuss where we are now, and which research areas are considered essential for the field in the future. We examine the scientific history of DS bridging these milestones in research to current efforts in the field. We extrapolate on comorbidities associated with this phenotype and highlight clinical networks in the USA and Europe pursuing clinical research, concluding with funding efforts and recent recommendations to the NIH regarding DS research.

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.

Cognitive Function during the Prodromal Stage of Alzheimer's Disease in Down Syndrome: Comparing Models

Accurate identification of the prodromal stage of Alzheimer’s disease (AD), known as mild cognitive impairment (MCI), in adults with Down syndrome (MCI-DS) has been challenging because there are no established diagnostic criteria that can be applied for people with lifelong intellectual disabilities (ID). As such, the sequence of cognitive decline in adults with DS has been difficult to ascertain, and it is possible that domain constructs characterizing cognitive function in neurotypical adults do not generalize to this high-risk population. The present study examined associations among multiple measures of cognitive function in adults with DS, either prior to or during the prodromal stage of AD to determine, through multiple statistical techniques, the measures that reflected the same underlying domains of processing. Participants included 144 adults with DS 40–82 years of age, all enrolled in a larger, multidisciplinary study examining biomarkers of AD in adults with DS. All participants had mild or moderate lifelong intellectual disabilities. Overall AD-related clinical status was rated for each individual during a personalized consensus conference that considered performance as well as health status, with 103 participants considered cognitively stable (CS) and 41 to have MCI-DS. Analyses of 17 variables derived from 10 tests of cognition indicated that performance reflected three underlying factors: language/executive function, memory, and visuomotor. All three domain composite scores significantly predicted MCI-DS status. Based upon path modeling, the language/executive function composite score was the most affected by prodromal AD. However, based upon structural equation modeling, tests assessing the latent construct of memory were the most impacted, followed by those assessing visuomotor, and then those assessing language/executive function. Our study provides clear evidence that cognitive functioning in older adults with DS can be characterized at the cognitive domain level, but the statistical methods selected and the inclusion or exclusion of certain covariates may lead to different conclusions. Best practice requires investigators to understand the internal structure of their variables and to provide evidence that their variables assess their intended constructs.

Mental State Language Use in Children with Down Syndrome and the Role of Caregivers

Children with Down syndrome (DS) have both strengths and difficulties in speech, language, and social communication. Mental state language-the ability to discuss others' perspectives such as their thoughts, feelings, and intentions-represents a foundational social communicative skill that is delayed in many children with DS, even into the school-age years. The purpose of this article is to review the evidence base on mental state language development in school-age children with DS, focusing in particular on assessment and intervention. We discuss assessment procedures that are both age appropriate and developmentally appropriate for this population. We also present preliminary data highlighting the role of caregivers in supporting mental state language development in school-age children with DS through shared storytelling. We propose that interventions aimed at supporting mental state language development in DS should include a focus on caregiver-child shared storybook reading, even in the school-age years. Therefore, we discuss key considerations for clinicians when teaching caregivers strategies for supporting mental state language and social communication in children with DS.

Reading Skills in Down Syndrome: Implications for Clinical Practice

Though children with Down syndrome can learn to read, they may have difficulty developing some component skills, including phonological awareness and word decoding. Given reading's foundation in language, speech-language pathologists (SLPs) should play a central role in supporting access to and providing reading instruction for children with Down syndrome. This article reviews the available research on reading in Down syndrome and offers guidance for SLPs working with this population. We start by reviewing the Down syndrome phenotype, highlighting physical features and cognitive and linguistic patterns of strength and weakness that impact reading development. Next, we define different reading subskills and outline typical reading development, including stages of prereading, learning to read, and transitioning to using reading as a tool for learning. We then use these stages to review what is known about reading in Down syndrome, including relevant intervention work. We also incorporate considerations for clinical practice. In particular, we encourage SLPs to advocate for supporting reading development in children with Down syndrome, to work with families to develop rich home literacy environments, and to work with educators to promote phonological awareness and decoding skills. Lastly, we note limitations in our current knowledge and include a call for more research.

The impact of sleep problems on functional and cognitive outcomes in children with Down syndrome: a review of the literature

STUDY OBJECTIVES

The aim of this review was to summarize the existing literature on the association between sleep problems and cognition, function, and behavior in children with Down syndrome.

METHODS

Embase, PubMed, CINAHL, and PsychINFO databases were searched to retrieve all studies published between 1990 and 2018 that evaluated the relationship between sleep and cognition, function, or behavior in children with Down syndrome.

RESULTS

Fifteen articles were included, which were mostly of a cohort or case-controlled design. Five articles addressed sleep and cognition only, 6 reported on sleep and behavior, and only 1 reported on sleep and functional ability. Three papers evaluated sleep and both cognition and behavior. Findings varied across studies with methodological differences, making it difficult to directly compare results. The association between sleep and behavior or cognition in children with Down syndrome remains uncertain, but a large study in 110 children provides strong evidence of a negative impact of sleep disorders on the accomplishment of daily life habits.

CONCLUSIONS

The impact of coexisting sleep disorders in children with Down syndrome has not been widely studied, with only 15 relevant studies found through an extensive literature review. Large well-designed studies are required to fully understand this relationship further. This is important as sleep-disordered breathing and difficulties with sleep patterns and routines are highly prevalent in children with Down syndrome. Sleep may be one of the few treatable factors that can assist in improving long-term outcomes in this population.

Assessing Phonological Profiles in Children and Adolescents With Down Syndrome: The Effect of Elicitation Methods

In the context of comparing linguistic profiles across neurodevelopmental disorders, Down syndrome (DS) has captured growing attention for its uneven profile. Although specific weaknesses in grammatical and phonological processing have been reported, research evidence on phonological development remains scarce, particularly beyond early childhood. The purpose of this study was to explore the phonological profiles of children and adolescents with Down syndrome. The profiles were based on the frequency and relative proportion of the processes observed by classes, and they were compared to those of typically developing preschool children of similar verbal age. A complementary goal was to assess the effect of two different methods of elicitation: a test of articulation and spontaneous speech sampling. Finally, intergroup and intragroup differences in full match percentages between three positions at syllable-level (complex onset, medial coda, and final coda) were assessed. The results of the present study confirmed that the frequency of phonological processes in children and adolescents with DS is atypically high and is above what is expected for lexical age and at the same level as grammatical age. Highly increased frequency of processes, consistent in all kinds of processes and positions at the syllable-level, and asynchronous with verbal age and mental age suggest atypical developmental trajectories of phonological development in the Down syndrome population.

Characterization of Sleep Disturbances in Children and Adolescents with Down Syndrome and Their Relation with Cognitive and Behavioral Features

Despite sleep disturbances are common among youths with Down syndrome (DS), the cognitive and behavioral features associated with sleep problems have not yet been studied extensively. The present study investigated the presence of sleep disturbances in a group of children and adolescents with DS and their cognitive and behavioral correlates. Seventy-one children and adolescents with DS underwent a neuropsychological evaluation, whereas parents completed questionnaires for the screening of the child's sleep, emotional and behavioral problems. We found no association between sleep disturbances and sex, nonverbal IQ, nor adaptive abilities. However, we found that age was positively associated with disorders in initiating and maintaining sleep (DIMS) and disorders of excessive somnolence (DOES), while body mass index was related with DOES. We also detected a relationship between visual-motor integrations and DIMS, as well as multiple associations between sleep disturbances and psychopathological and behavioral problems, mainly externalizing symptoms. The present study provided a detailed characterization of sleep problems in relation to several features of youths with DS. The proper identification of sleep disturbances profile in the DS population could support the process of clinical evaluation, in particular for psychopathological aspects.

Parent-based training of basic number skills in children with Down syndrome using an adaptive computer game

BACKGROUND

Numeracy is an area of difficulty for children with Down syndrome (DS). It has been demonstrated that The Number Race, a non-commercial adaptive computer game designed to foster basic mathematical abilities, represents a promising instrument to enhance these skills in children with DS when delivered by an expert in a clinical setting.

AIMS

In the present study, we assessed the efficacy of The Number Race when administered at home by properly instructed and remotely supervised parents.

METHODS AND PROCEDURES

Basic numerical skills were assessed before and after training, as well as at three-months follow-up. Performance of children with DS who worked at home with the parent (PG) was compared with that of children who received the training by an expert (EG). For both groups, the training lasted ten weeks, with two weekly sessions of 20-30 min.

OUTCOMES AND RESULTS

Results show that both groups improved across various measures of numerical proficiency, including the overall score of the numeracy assessment battery, while only the EG showed an improvement in a measure of mental calculation. The improvements were maintained three months after the end of the training.

CONCLUSIONS AND IMPLICATIONS

These findings confirm the efficacy of The Number Race and extend it to an home-based setting, whereby parents administer the training with external supervision.

Capturing cognitive and behavioral variability among individuals with Down syndrome: a latent profile analysis

BACKGROUND

There is a high degree of inter- and intra-individual variability observed within the phenotype of Down syndrome. The Down Syndrome Cognition Project was formed to capture this variability by developing a large nationwide database of cognitive, behavioral, health, and genetic information on individuals with Down syndrome, ages 6-25 years. The current study used the Down Syndrome Cognition Project database to characterize cognitive and behavioral variability among individuals with Down syndrome.

METHODS

Latent profile analysis was used to identify classes across a sample of 314 participants based on their cognition (IQ and executive functioning), adaptive and maladaptive behavior, and autism spectrum disorder symptomatology. A multivariate multinomial regression model simultaneously examined demographic correlates of class.

RESULTS

Results supported a 3-class model. Each class demonstrated a unique profile across the subdomains of cognition and behavior. The "normative" class was the largest (n = 153, 48%) and displayed a relatively consistent profile of cognition and adaptive behavior, with low rates of maladaptive behavior and autism symptomatology. The "cognitive" class (n = 109, 35%) displayed low cognitive scores and adaptive behavior and more autism symptomatology, but with low rates of maladaptive behavior. The "behavioral" class, the smallest group (n = 52, 17%), demonstrated higher rates of maladaptive behavior and autism symptomatology, but with cognition levels similar to the "normative" class; their adaptive behavior scores fell in between the other two classes. Household income and sex were the only demographic variables to differ among classes.

CONCLUSIONS

These findings highlight the importance of subtyping the cognitive and behavioral phenotype among individuals with Down syndrome to identify more homogeneous classes for future intervention and etiologic studies. Results also demonstrate the feasibility of using latent profile analysis to distinguish subtypes in this population. Limitations and future directions are discussed.

Caregivers' perceptions and experience of caring for persons with Down syndrome in Kuwait: a qualitative study

Aim and Objective: This study aimed to explore how caregivers of persons with Down syndrome (DS) believe caring had an impact on their own lives. A secondary objective was to understand their experience of seeking educational, social, and health care services for the persons with DS. Methods: This qualitative exploratory study was conducted with 21 caregivers of persons with DS in Kuwait. Results: Caregivers struggled to accept the diagnosis initially that led them to search for answers to many of their concerns about raising a person with DS. For the caregivers, who mostly comprised of mothers, dealing with health conditions that persons with DS suffered from was initially difficult. Caring for these individuals led to heavy impact upon their caregivers' own lives who took extraordinary efforts to cope with the burden. Seeking quality education for the persons with DS and participation in social activities was also challenging, and the caregivers believed that better services, facilities, and benefits for the families of persons with DS may help them better cope with the socioeconomic and psychological burden. Conclusions: Improving the availability of specialized services, the delivery of guidance and counselling, and social integration may help overcome challenges of raising a person with Down Syndrome.

[Cognition in Down's Syndrome: Development across the Life Span and Neuropsychological Assessment in Adults]

Das Down-Syndrom ist die häufigste genetische Ursache einer Intelligenzminderung. Da Menschen mit einem Down-Syndrom ein erhöhtes Risiko aufweisen, an einer Alzheimer-Demenz zu erkranken, ist eine umfassende Untersuchung der kognitiven Funktionen indiziert, sowohl im jungen Erwachsenenalter (zur Erhebung des kognitiven Ausgangsniveaus) als auch im Verlauf zur Demenzdiagnostik. Das weite Spektrum an kognitiver Leistungsfähigkeit bei Menschen mit einem Down-Syndrom stellt eine diagnostische Herausforderung dar. Wir möchten daher einen Überblick geben (1) über die kognitive Entwicklung über die Lebensspanne, (2) über verschiedene mögliche Ursachen kognitiver Veränderungen bei erwachsenen Menschen mit einem Down-Syndrom und (3) über neuropsychologische Diagnostik und entsprechende Verfahren für den Erwachsenenbereich. Schließlich geben wir, auf der Grundlage unserer Erfahrungen, (4) allgemeine Empfehlungen zur Untersuchung und Befundinterpretation bei Menschen mit Intelligenzminderung.

Monozygotic twins discordant for homologous Robertsonian translocation trisomy 21 of 46, XX, + 21, der (21;21) (q10; q10) in a twin-to-twin transfusion syndrome, case report

Background

Monozygotic twins are nearly identical in genotype and phenotype because monozygotic twins arise from one fertilized oocyte. In all cases of discordant karyotype in monozygotic twins, trisomy 21 accounts for about one in 385,000. Monozygotic twins discordant for Robertsonian translocation trisomy 21 of the der (21;21)(q10;q10), in which the additional chromosome originates from the father is rare.

Case presentation

A 28-year-old parous woman, G3P1A0, came to our institution for a dating scan at 8 weeks of gestation. The transvaginal ultrasound examination demonstrated a monochorionic diamniotic pregnancy. She and her husband were healthy, with no family history of trisomy 21 or other congenital diseases. The ultrasound examination of nuchal translucency thickness was discordant in twins at 13 weeks (twin A, NT 1.4 mm with CRL being 65 mm; twin B, NT 7.8 mm with CRL being 69 mm). At 17^+ 4 weeks, twin A was normal, but ventricular septal defect and the hypoplastic left heart was detected in twin B. The deepest vertical pocket was 18 mm in twin A (oligohydramnios) and 102 mm in Twin B (polyhydramnios). The bladder in twin A was absent. Ultrasound findings indicated TTTS Stage II. Amniocentesis was performed for the two fetuses. The karyotyping results revealed 46, XX in twin A but 46,XX,+ 21,der (21;21)(q10;q10) in twin B.

For twin B, the parents opted for selective fetal termination by radiofrequency ablation. The procedure was uneventful. At 40^+ 5 weeks, twin A was born with a birth weight of 4120 g by vaginal delivery.

Conclusions

The early detection of discordant karyotype and twin-to-twin transfusion syndrome is beneficial to the early intervention. In monozygotic twins with a discordant anomaly, the discordant karyotype should be considered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03587-x.

Family Variables and Quality of Life in Children with Down Syndrome: A Scoping Review

The purpose of this scoping review was to identify the family and child quality of life variables that have been studied in relation to one another in children with Down syndrome, the frequency with which different relationships have been studied, and the extent to which family variables were the focus of the research aims. A literature search was conducted to find studies published between January 2007 and June 2018. The initial search yielded 2314 studies; of these, 43 were selected for a final review. Researchers most often addressed family resources and family problem-solving and coping concerning child personal development and physical well-being. Little attention to child emotional well-being was observed, with none considering family appraisal of child emotional well-being. The relationship between family variables and child QoL rarely was the primary focus of the study. Methodologically, most reviewed studies used cross-sectional designs, were conducted in North America and based on maternal report. From future research considering the issues found in this review, healthcare providers can obtain an in-depth understanding of relationships between children and family variables.

Regional Alterations in Cortical Sulcal Depth in Living Fetuses with Down Syndrome

Down syndrome (DS) is the most common genetic cause of developmental disabilities. Advanced analysis of brain magnetic resonance imaging (MRI) has been used to find brain abnormalities and their relationship to neurocognitive impairments in children and adolescents with DS. Because genetic factors affect brain development in early fetal life, there is a growing interest in analyzing brains from living fetuses with DS. In this study, we investigated regional sulcal folding depth as well as global cortical gyrification from fetal brain MRIs. Nine fetuses with DS (29.1 ± 4.24 gestational weeks [mean ± standard deviation]) were compared with 17 typically developing [TD] fetuses (28.4 ± 3.44). Fetuses with DS showed lower whole-brain average sulcal depths and gyrification index than TD fetuses. Significant decreases in sulcal depth were found in bilateral Sylvian fissures and right central and parieto-occipital sulci. On the other hand, significantly increased sulcal depth was shown in the left superior temporal sulcus, which is related to atypical hemispheric asymmetry of cortical folding. Moreover, these group differences increased as gestation progressed. This study demonstrates that regional sulcal depth is a sensitive marker for detecting alterations of cortical development in DS during fetal life, which may be associated with later neurocognitive impairment.

Outcomes in Hirschsprung's disease with coexisting learning disability

This study describes functional and health-related quality of life (HRQoL) outcomes in patients with Hirschsprung's disease (HSCR) with associated learning disability or neurodevelopmental delay (LD), completing a core outcome set for HSCR. This was a cross-sectional study from a tertiary pediatric surgery center. Patients treated between 1977 and 2013 were prospectively contacted to complete an outcomes survey. Children under 12 and older patients with LD were assisted to complete these by a proxy. Bowel and urologic function were assessed (Rintala's BFS and modified DanPSS) along with HRQoL (PedsQL/GIQLI/SF-36). Thirty-two patients with LD were compared to 186 patients with normal cognition. Patients with LD had 76% survival over the follow-up period, compared to 99% in the remainder of the cohort. Poor functional outcomes were common in the patients with LD, considerably higher than cognitively normal patients: with weekly issues withholding stool, soiling and fecal accidents in over half of patients surveyed (44-60%), and urinary incontinence in 46%. Use of permanent stoma was significantly higher (22% vs. 4%; p = 0.001). HRQoL was worse in domains of physical functioning in adults and children but not for social or emotional domains in adults. Subgroup analysis of patients with Down syndrome suggested similar functional results but better QoL. Multivariate analysis demonstrated a dramatically higher incidence of poor continence outcomes in patients with LD (adjusted OR 9.6 [4.0-23]).Conclusions: We provide LD-specific outcomes showing inferior function but similar HRQoL to other patients with HSCR, this is much needed in the counselling of families of these children. What is Known: • Hirschsprung's disease is commonly associated with syndromes or other anomalies with resultant cognitive impairments. • The outcomes for these patients specifically have been poorly described in the literature. What is New: • Objective functional and quality of life surveys demonstrate significant differences from patients without cognitive impairment. • Patients with learning disability Patients with associated LD were almost ten times more likely to have an associated poor functional outcome, with very little impact on proxy-reported quality of life.

Quality of life in individuals with Down syndrome aged 4 to 21 years

BACKGROUND

To date, investigations of quality of life (QoL) in children with Down syndrome (DS) are rather limited. The purpose of this study was twofold: to examine QoL in children with DS and to explore possible differences in the QoL by age and gender.

METHODS

A cross-sectional study of 211 parents of children with DS was conducted using an online survey that included a consent form, a demographic questionnaire and the English version of KidsLife, which is a measure of children's QoL.

RESULTS

Our results demonstrated moderate or favourable levels of QoL except for the emotional well-being domain among children with DS. The children's QoL showed no variance by gender. However, emotional and material well-being, interpersonal relations and social inclusion varied by age.

CONCLUSIONS

The current findings provide important evidence that will help healthcare, educational and social services professionals to understand the multiple aspects of QoL in children with DS and support parents in their efforts to ensure the child's QoL. The results also point to the need to develop interventions aimed at improving QoL in those areas where children with DS are at increased risk for poorer QoL.

Low Rates of Preventive Healthcare Service Utilization Among Adolescents and Adults With Down Syndrome

INTRODUCTION

People with Down syndrome have health risks that require specific lifelong preventive health care. With increasing life expectancy, people with Down syndrome also face health conditions typical of their unaffected peers and thus need coordinated health care. The purpose of this study is to describe rates of age/sex- and Down syndrome-specific preventive healthcare activities among adolescents and adults with Down syndrome.

METHODS

Using Medicaid claims (2006-2010) in California, Colorado, Michigan, and Pennsylvania, the cohort was defined as people with Down syndrome aged ≥12 years seen by primary care providers and enrolled in Medicaid for ≥45 of 60 months without dual Medicare enrollment (n=3,501). Age focus-consistent primary care providers were defined as having a focus concordant with a patient's age: 12-17 years, child or mixed-focus; ≥26 years, adult or mixed-focus; 18-25 years, any focus. Differences in healthcare activities were evaluated using Pearson's chi-square, Fisher's exact, and Kruskal-Wallis tests. Analyses were performed in 2015-2017.

RESULTS

Of the cohort, 79% had an age focus-consistent primary care provider. However, 40% of adults aged ≥26 years received care from a child-focused primary care provider. Only 43% with an age focus-consistent provider had ≥1 well examination (age focus-inconsistent primary care provider: 35%, p<0.001). Most preventive activities had poor rates (<50%) regardless of age focus consistency between provider and patient age or whether they were age/sex- or Down syndrome-specific (well examinations; vaccinations; sleep apnea; hearing; and breast, cervical, and colon cancer screenings). Lipids, vision, and thyroid screenings reached moderate levels (50% to <80%).

CONCLUSIONS

Rates of age/sex- and Down syndrome-specific preventive recommendations were low among adolescents and adults with Down syndrome, regardless of the age focus consistency of their primary care provider. This represents a significant opportunity to improve primary care in this vulnerable population.

A meta-analysis of prosody in autism, Williams syndrome, and Down syndrome

Prosody, the rhythm and melody of speech, is an important component of effective communication, and it is an area of difficulty for many populations who struggle with communication. This paper is a meta-analysis of nine studies (and two sets of unpublished data) that assessed prosody using the Profiling Elements of Prosody in Speech-Communication (PEPS-C; Peppé & McCann, 2003) in autism spectrum disorder, Williams syndrome, and Down syndrome. Our original goal was to include studies involving any neurodevelopmental disorder that is commonly associated with intellectual disability, yet our systematic search, which included three databases (i.e., PsychInfo, ERIC, and PubMed), only identified studies involving these three groups. To be included in the meta-analysis, studies had to include a group (n ≥ 3 participants) with a neurodevelopmental disorder commonly associated with intellectual disability and a typically developing comparison group matched on chronological age, nonverbal abilities, or verbal abilities. Studies also needed to report original data using the PEPS-C and be available in English. Study quality was assessed using a checklist adapted from Downes et al. (2016). Results revealed that prosodic form was a weakness for each etiology, while unique patterns of strengths and weaknesses were evident for prosodic functions. Groups with autism (n = 5), all classified as high-functioning or with Asperger's syndrome, exhibited weakness in emotional affect but some relative strengths with turn-end and focus tasks. Groups with Williams syndrome (n = 4) demonstrated weaknesses on phrase/sentence-level tasks and relative strengths on word-level tasks. Groups with Down syndrome (n = 2) had the greatest difficulty overall, though performance was better on receptive (vs. expressive) function tasks. By combining studies and related subtasks of the PEPS-C, we are able to more confidently generalize findings for each population and identify targets for intervention. However, given the limited number of studies identified, this paper also highlights the need for more research on prosody in intellectual disability.

The Influence of Hearing Impairment on Mental Age in Down Syndrome: Preliminary Results

The increased life expectancy for patients with Down Syndrome (DS) has elicited the need to improve their quality of life by enhancing functional outcomes and identifying the factors that contribute to their long-term cognitive decline. Although the majority of individuals with DS have issues with hearing impairment (HI) since early childhood, to our knowledge no study has investigated whether HI represents a potential modulator of cognitive decline over time. The present explorative cohort study, albeit very preliminary due to the limited cohort (17 children), highlights the significant relation of a significant HI not only with receptive language abilities, but also with mental age in young patients with DS. Additional studies are required to confirm the link between HI and mental age and to assess the impact of audiological treatment on the enhancement of functional outcomes and of cognitive decline in individuals with DS.

Enhanced learning to improve letter knowledge in children with Down syndrome and severe intellectual disability: A case report

Children with Down syndrome and severe intellectual disability have difficulties in learning a language. Enhanced learning procedure, including mora segmentation is beneficial to understand letter-sound correspondence in such children.

Distinct patterns of repetition suppression in Fragile X syndrome, down syndrome, tuberous sclerosis complex and mutations in SYNGAP1

Sensory processing is the gateway to information processing and more complex processes such as learning. Alterations in sensory processing is a common phenotype of many genetic syndromes associated with intellectual disability (ID). It is currently unknown whether sensory processing alterations converge or diverge on brain responses between syndromes. Here, we compare for the first time four genetic conditions with ID using the same basic sensory learning paradigm. One hundred and five participants, aged between 3 and 30 years old, composing four clinical ID groups and one control group, were recruited: Fragile X syndrome (FXS; n = 14), tuberous sclerosis complex (TSC; n = 9), Down syndrome (DS; n = 19), SYNGAP1 mutations (n = 8) and Neurotypical controls (NT; n = 55)). All groups included female and male participants. Brain responses were recorded using electroencephalography (EEG) during an audio-visual task that involved three repetitions of the pronunciation of the phoneme /a/. Event Related Potentials (ERP) were used to: 1) compare peak-to-peak amplitudes between groups, 2) evaluate the presence of repetition suppression within each group and 3) compare the relative repetition suppression between groups. Our results revealed larger overall amplitudes in FXS. A repetition suppression (RS) pattern was found in the NT group, FXS and DS, suggesting spared repetition suppression in a multimodal task in these two ID syndromes. Interestingly, FXS presented a stronger RS on one peak-to-peak value in comparison with the NT. The results of our study reveal the distinctiveness of ERP and RS brain responses in ID syndromes. Further studies should be conducted to understand the molecular mechanisms involved in these patterns of responses.

Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

Clinical observations and preclinical studies both suggest that Down syndrome (DS) may be associated with significant metabolic and bioenergetic alterations. However, the relevant scientific literature has not yet been systematically reviewed. The aim of the current study was to conduct a meta-analysis of metabolites involved in bioenergetics pathways in DS to conclusively determine the difference between DS and control subjects. We discuss these findings and their potential relevance in the context of pathogenesis and experimental therapy of DS. Articles published before July 1, 2020, were identified by using the search terms “Down syndrome” and “metabolite name” or “trisomy 21” and “metabolite name”. Moreover, DS-related metabolomics studies and bioenergetics literature were also reviewed. 41 published reports and associated databases were identified, from which the descriptive information and the relevant metabolomic parameters were extracted and analyzed. Mixed effect model revealed the following changes in DS: significantly decreased ATP, CoQ10, homocysteine, serine, arginine and tyrosine; slightly decreased ADP; significantly increased uric acid, succinate, lactate and cysteine; slightly increased phosphate, pyruvate and citrate. However, the concentrations of AMP, 2,3-diphosphoglycerate, glucose, and glutamine were comparable in the DS vs. control populations. We conclude that cells of subjects with DS are in a pseudo-hypoxic state: the cellular metabolic and bio-energetic mechanisms exhibit pathophysiological alterations that resemble the cellular responses associated with hypoxia, even though the supply of the cells with oxygen is not disrupted. This fundamental alteration may be, at least in part, responsible for a variety of functional deficits associated with DS, including reduced exercise difference, impaired neurocognitive status and neurodegeneration.

Parent-Reported Contribution of Family Variables to the Quality of Life in Children with Down Syndrome: Report from an International Study

PURPOSE

The intent of this study was to determine parents' views of the contribution of family variables to the quality of life (QoL) of children with Down Syndrome (DS). Based on prior research, we hypothesized that parents would report that family variables reflecting positive aspects of family functioning contributed to better QoL; and family variables reflecting the negative aspects of family functioning contributed to poorer QoL.

DESIGN AND METHODS

A cross-sectional study was carried out. Invitation letters were sent to DS support groups. Upon agreement, the parents of the children were sent a link to an online survey that included a consent form, demographic questionnaire, and child and family measures.

RESULTS

Results demonstrated the contribution of family demands to children's interpersonal relations. Family appraisals concerning the child and the family's ability predicted the children's physical and material well-being, personal development, self-determination, social inclusion, interpersonal relations, and rights. Family problem-solving served as a prominent predictor for children's physical and emotional well-being, personal development, interpersonal relations, and rights. Also, family resources predicted various aspects of children's QoL including physical, emotional, and material well-being, self-determination, social inclusion, interpersonal relations, and rights.

CONCLUSION

Results confirmed the significant relationship between family and children's QoL variables. Family appraisal and family problem-solving were especially identified as significant predictors of children's QoL that can be targeted for family interventions, since the family variables are modifiable aspects of family life.

PRACTICE IMPLICATIONS

Nurses can use current findings to develop interventions to enhance QoL of children with DS and families.

Intelligence trajectories in adolescents and adults with down syndrome: Cognitively stimulating leisure activities mitigate health and ADL problems

GOALS

This study examined: (a) crystallized/fluid intelligence trajectories of adolescents and adults with Down syndrome; and (b) the contribution of endogenous (health, activities of daily living-ADL) and exogenous (cognitively stimulating leisure activities) factors on adults' intelligence with age.

METHOD

Four cohorts (N = 80) with Down syndrome participated: adolescents (ages 16-21) and adults (ages 30-45, 46-60 and 61+). All completed Vocabulary and Similarities (crystallized) and Block Design and Raven (fluid) intelligence tests (WAIS-III^HEB , Wechsler, 2001).

RESULTS

The 30-45 cohort significantly outperformed the 16-21 cohort. Except for Vocabulary, which remained stable, onset of decline was at 40-50. Age-related declining health and ADL correlated with participants' lower fluid intelligence, but cognitive leisure activities mitigated this influence.

CONCLUSIONS

Intelligence development into adulthood supported the continuous trajectory and compensation age theory, rather than accelerated or stable trajectories. Not only endogenous factors but also exogenous factors determined intelligence levels in adults with Down syndrome, supporting cognitive activity theory.

Family Sense-Making After a Down Syndrome Diagnosis

The script of parenting shifts when parents learn of their child's Down syndrome diagnosis. To build a theory of the diagnostic experience and early family sense-making process, we interviewed 33 parents and nine grandparents living in the United States who learned prenatally or neonatally of their child's diagnosis. The core category of rescuing hope for the future encompassed the social process of sense-making over time as parents managed their sorrow, shock, and grief and amassed meaningful messages that anchored them as they looked toward the future. Application of the theory to practice underscores the import of early professional support offered to parents at key points in the sense-making process: Early as they disclose the news of the diagnosis to family and friends, and later close friends and kin assimilate meaningful messages about what the diagnosis means as they recalibrate expectations for a hopeful future.

Neurologic complications of Down syndrome: a systematic review

Down syndrome (DS) is one of the most well-recognized genetic disorders. Persons with DS are known to have a variety of co-morbid medical problems, affecting nearly all organ systems. Improved healthcare interventions and research have allowed for increased life span of persons with DS, although disorders of the neurologic system remain underexplored. The purpose of this systematic review is to provide clinically pertinent information on the neurological phenotypes of frequently occurring or clinically relevant conditions. A retrospective review of MEDLINE, Scopus, and Pubmed were used to identify sources among seventeen, clinically relevant, search categories. MeSH terms all contained the phrase "Down Syndrome" in conjunction with the topic of interest. 'Frequently-occurring' was defined as prevalent in more than 10% of persons with DS across their lifespan, whereas 'clinically-relevant' was defined as a disease condition where early diagnosis or intervention can augment the disease course. In total, 4896 sources were identified with 159 sources meeting criteria for inclusion. Seventeen clinical conditions were grouped under the following subjects: hypotonia, intellectual and learning disability, cervical instability, autism spectrum disorder, epilepsy, cerebrovascular disease, Alzheimer's disease and neuropsychiatric disease. The results of this review provide a blueprint for the clinical neurologist taking care of persons with DS across the age spectrum and indicate that there are many underrecognized and misdiagnosed co-occurring conditions in DS, highlighting the need for further research.

Behavioral Audiology Procedures in Children With Down Syndrome

Purpose Normative data regarding behavioral audiologic testing procedures are based upon the general population and often do not apply to children with Down syndrome (DS). Testing children with DS can be challenging, and outcomes may be unreliable due to their different cognitive demands and delays. The aim of this study was to assess optimal audiologic testing procedures for specific age groups of children with DS. Method This study used a retrospective investigation of 273 children with DS (145 boys, 128 girls; average age at evaluation = 5.92 ± 4.74 years) who received an audiologic evaluation during 2013 as part of their medical care at a large pediatric hospital (satellite facilities included). Results Age ranges for the completion of audiometry procedures in children with DS are provided. Average age to reliably complete behavioral testing in children with DS was delayed by up to 30 months compared to typically developing children. The majority of children with DS achieved at least good-to-fair reliability for audiologic results starting at 16 months (85.7%) and two ear results at 6-10 years (76.1%). Though not statistically significant, the use of a two-tester assistant compared to a single tester appeared to be helpful in obtaining reliable results. Conclusion The results provide a guide to optimal audiologic test procedures for children with DS, as the standard audiologic guidelines for typically developing infants and children do not apply.

Obstructive Sleep Apnoea Contributes to Executive Function Impairment in Young Children with Down Syndrome

OBJECTIVE/BACKGROUND

Children with Down syndrome (DS) commonly experience difficulties with executive function (EF). They are also vulnerable to obstructive sleep apnoea (OSA). OSA is associated with EF deficits in typically developing children. A recent study reported an association between OSA and cognitive deficits in 38 school-aged children with DS. We experimentally investigated EF behaviours in young children with DS, and their association with OSA.

PARTICIPANTS AND METHODS

Children with DS were recruited to take part in a larger study of OSA (N = 202). Parents of 80 children (50 male) aged 36 to 71 months (M = 56.90, SD = 10.19 months) completed the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P). Of these 80 children, 69 were also successfully studied overnight with domiciliary cardiorespiratory polygraphy to diagnose OSA.

RESULTS

Obstructive apnoea/hypopnoea index was in the normal range (0-1.49/h) for 28 children but indicated OSA (≥1.5/h) in 41 children. Consistent with previous research, we found a large effect for children experiencing particular weaknesses in working memory, planning and organising, whilst emotional control was a relative strength. OSA was associated with poorer working memory (β = .23, R2 = .05, p = .025), emotional control (β = .20, R2 = .04, p = .047) and shifting (β = .24, R2 = .06, p = .023).

CONCLUSIONS

Findings suggest that known EF difficulties in DS are already evident at this young age. Children with DS already have limited cognitive reserve and can ill afford additional EF deficit associated with OSA. OSA is amenable to treatment and should be actively treated in these children to promote optimal cognitive development.

Language skills as a predictor of cognitive decline in adults with Down syndrome

INTRODUCTION

Adults with Down syndrome (DS) are at high risk for early onset Alzheimer's disease (AD), characterized by a progressive decline in multiple cognitive domains including language, which can impact social interactions, behavior, and quality of life. This cross-sectional study examined the relationship between language skills and dementia.

METHODS

A total of 168 adults with DS (mean age = 51.4 years) received neuropsychological assessments, including Vineland Communication Domain, McCarthy Verbal Fluency, and Boston Naming Test, and were categorized in one of three clinical groups: cognitively stable (CS, 57.8%); mild cognitive impairment (MCI-DS, 22.6%); and probable/definite dementia (AD-DS, 19.6%). Logistic regression was used to determine how well language measures predict group status.

RESULTS

Vineland Communication, particularly receptive language, was a significant predictor of MCI-DS. Semantic verbal fluency was the strongest predictor of AD-DS.

DISCUSSION

Assessment of language skills can aid in the identification of dementia in adults with DS. Clinically, indications of emerging language problems should warrant further evaluation and monitoring.