Growing up with Down syndrome: Development from 6 months to 10.7 years

How do Children with Intellectual Disabilities Empathize in Comparison to Typically Developing Children?

OBJECTIVES

Two studies were conducted to better understand how children with intellectual disabilities (ID) empathize with the feelings of others during social interactions. The first study tested hypotheses of developmental delay or difference regarding empathy in 79 children with ID by comparing them with typically developing (TD) children, matched for developmental age or chronological age. The second study examined specific aspects of empathy in 23 children with Down syndrome (DS), compared with 23 nonspecific ID children, matched for developmental age, and TD children, matched for developmental age or chronological age.

METHOD

An empathy task was administered to the children while their parents completed the French versions of the Empathy Questionnaire and the Griffith Empathy Measure.

RESULTS

The first study showed that ID children showed delayed empathy development but were perceived by their parents as deficient in cognitive empathy. The second study showed that DS children were perceived as being more attentive to the feelings of others than TD children and non-specific ID children, matched for developmental age, and as having affective empathy that was similar to that of TD children matched for chronological age.

CONCLUSION

These studies have drawn attention to delays or differences in different dimensions of empathy in children with ID and DS, which need to be taken into account in interventions.

Sex-specific developmental alterations in DYRK1A expression in the brain of a Down syndrome mouse model

Aberrant neurodevelopment in Down syndrome (DS)-caused by triplication of human chromosome 21-is commonly attributed to gene dosage imbalance, linking overexpression of trisomic genes with disrupted developmental processes, with DYRK1A particularly implicated. We hypothesized that regional brain DYRK1A protein overexpression in trisomic mice varies over development in sex-specific patterns that may be distinct from Dyrk1a transcription, and reduction of Dyrk1a copy number from 3 to 2 in otherwise trisomic mice reduces DYRK1A, independent of other trisomic genes. DYRK1A overexpression varied with age, sex, and brain region, with peak overexpression on postnatal day (P) 6 in both sexes. Sex-dependent differences were also evident from P15-P24. Reducing Dyrk1a copy number confirmed that these differences depended on Dyrk1a gene dosage and not other trisomic genes. Trisomic Dyrk1a mRNA and protein expression were not highly correlated. Sex-specific patterns of DYRK1A overexpression during trisomic neurodevelopment may provide mechanistic targets for therapeutic intervention in DS.

BENDI: Improving Cognitive Assessments in Toddlers and Children with Down Syndrome Using Stealth Assessment

Cognitive assessment is a fundamental step in diagnosing intellectual and developmental disabilities, designing interventions, and evaluating their impact. However, developed and developing countries have different access to tools designed for these purposes. Our goal was to develop a battery for cognitive assessment mediated by digital technology that allows the exploration of cognitive domains (inhibitory control, attention, motor ability, and context memory) in children with Down Syndrome (DS) in Chile. Four tasks, based on established experimental paradigms modified to provide a game-like experience, were tested in 68 children with DS from 20 months to 12 years of age. We present evidence of reliability based on internal consistency and split-half analyses, with results ranging from adequate to excellent. Regarding validity, factorial and correlational analyses show evidence consistent with what was theoretically expected of internal structure, convergence, and divergence with other measures. Expected age trajectories were observed as well. Our data offer evidence that supports the use of tasks based on touch-screen devices for cognitive assessment in the population with DS. The tasks also have a low cultural load, so they could be validated and used in other contexts without the need for an adaptation process.

Touch may reduce cognitive load during assisted typing by individuals with developmental disabilities

Many techniques have attempted to provide physical support to ease the execution of a typing task by individuals with developmental disabilities (DD). These techniques have been controversial due to concerns that the support provider's touch can influence the typed content. The most common interpretation of assisted typing as an ideomotor phenomenon has been qualified recently by studies showing that users with DD make identifiable contributions to the process. This paper suggests a neurophysiological pathway by which touch could lower the cognitive load of seated typing by people with DD. The required sensorimotor processes (stabilizing posture and planning and executing manual reaching movements) and cognitive operations (generating and transcribing linguistic material) place concurrent demands on cognitive resources, particularly executive function (EF). A range of developmental disabilities are characterized by deficits in sensorimotor and EF capacity. As light touch has been shown to facilitate postural coordination, it is proposed that a facilitator's touch could assist the seated typist with sensorimotor and EF deficits by reducing their sensorimotor workload and thereby freeing up shared cognitive resources for the linguistic elements of the task. This is the first theoretical framework for understanding how a facilitator's touch may assist individuals with DD to contribute linguistic content during touch-assisted typing.

Determinants of hand function in children and adolescent with Down Syndrome-A scoping review

BACKGROUND

Down Syndrome (DS) is a genetic condition. Physical characteristics like short stature, hypotonia, small, and thick hands result in decreased grip and pinch strength and quality of fine motor tasks.

PURPOSE

The purpose of this review is to summarize the evidence of upper extremity physical characteristics and its influence on hand function in DS population.

STUDY DESIGN

A scoping review.

METHODOLOGY

A comprehensive electronic literature search was conducted through PubMed, CINAHL, Cochrane Library. The search was limited to articles written in English and published between 2010 to 2021. Additionally, books were referred for a better understanding of the hand function in DS. The Preferred Reporting Items for Systematic Review and Meta-Analysis extension for scoping reviews (PRISMA-ScR) was adopted to develop the protocol.

RESULTS

Following a detailed review of 28 articles meeting the inclusion criteria, fetuses with a diagnosis of DS are reported to have shortening of humerus on sonographic markers wherein 9% of fetuses had below 5th percentile shortening. Additionally, literature reports that during reaching there was increased trunk rotation (effect size = 0.88). DS population had 60% less grip strength, 33% less palmar pinch strength ,20% less key pinch strength and poor manual dexterity (CI = 4.5-5.5).

CONCLUSION

Findings of this review concludes that physical characteristics of the upper extremity have an influence on hand function performance in children and adolescents with DS.However, only arm length and hand span have been quantified and correlated with grip strength. Further work must focus on correlation of upper extremity anthropometry and overall hand function in children and adolscents with DS.

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

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

Early developmental profiles among infants with Down syndrome

BACKGROUND

Down syndrome (DS) generally predisposes children to a pattern of relative developmental strengths and challenges, but within-syndrome heterogeneity is also commonly observed across many dimensions. The present research examines whether heterogeneity in developmental presentation can be detected during infancy in DS and whether factors associated with differing profiles can be identified.

METHODS

Infants with DS (n = 75; age range: 3.9-17.6 months) were administered the Bayley Scales of Infant Development III (Bayley-III). A primary caregiver provided information regarding developmental history and family demographics. Latent profile analysis was conducted to identify whether early profiles were present across the five Bayley-III domains.

RESULTS

Three developmental profiles were observable within the sample: a 'Mild Delay' Profile, an 'Moderate Delay' Profile and a 'Pronounced Delay' Profile. In addition, chronological age, having received heart surgery and having received occupational therapy were associated with probability of profile membership.

CONCLUSIONS

Findings from this study contribute to the growing knowledgebase regarding heterogenous presentations associated with DS and can inform early intervention planning.

Rescue of deficits by Brwd1 copy number restoration in the Ts65Dn mouse model of Down syndrome

With an incidence of ~1 in 800 births, Down syndrome (DS) is the most common chromosomal condition linked to intellectual disability worldwide. While the genetic basis of DS has been identified as a triplication of chromosome 21 (HSA21), the genes encoded from HSA21 that directly contribute to cognitive deficits remain incompletely understood. Here, we found that the HSA21-encoded chromatin effector, BRWD1, was upregulated in neurons derived from iPS cells from an individual with Down syndrome and brain of trisomic mice. We showed that selective copy number restoration of Brwd1 in trisomic animals rescued deficits in hippocampal LTP, cognition and gene expression. We demonstrated that Brwd1 tightly binds the BAF chromatin remodeling complex, and that increased Brwd1 expression promotes BAF genomic mistargeting. Importantly, Brwd1 renormalization rescued aberrant BAF localization, along with associated changes in chromatin accessibility and gene expression. These findings establish BRWD1 as a key epigenomic mediator of normal neurodevelopment and an important contributor to DS-related phenotypes.

Perceived Stress in the Primary Caregivers of Adolescents with Asthma: A Cross-Sectional Study

This study aims to determine the impact of the disease on the perceived stress levels of caregivers of adolescents with asthma. A total of 140 primary caregivers, whose mean age was 45.43 years (SD = 5.03), of whom 85% were mothers, were assessed using the perceived stress questionnaire (PIP), and medical indicators related to asthma were recorded. Mean comparisons, correlations, and qualitative comparative analysis (QCA) models were used. The results indicated moderate levels of perceived stress in caregivers, no kinship differences were found, and age was negatively associated with perceived stress. QCA models suggested that perceived stress could be explained by a higher frequency of visits, poorer adherence, more frequent daily medication doses, and higher severity of asthma. In conclusion, the development of psychological interventions addressing the subjective overload of the family caregiver may benefit them, increasing their well-being, and in turn help to manage the emotional difficulties of adolescents.

A comparison of the physical fitness of individuals with intellectually disabilities autism spectrum disorders and Down syndrome diagnosis

Introduction: This article reports the physical abilities and physical wellness of three groups of children with different neurodevelopmental disabilities: Autism, Down Syndrome and Intellectual Disability. Methods: The causal-comparative research method was implemented in this study. The participants comprised 32 students with moderate intellectual disabilities, 18 with autism spectrum disorder, and 22 with down syndrome. The body mass index (BMI), flexibility, standing long jump, sitting height, stroke length, and medicine ball throwing levels were measured for physical fitness, and the groups were compared afterward. The Kruskal Wallis-H Test and Mann-Whitney U Test were applied to determine the differences between the groups' physical fitness averages for the statistical analysis. Results: Statistically significant differences were obtained in BMI, standing long jump, stroke length, and medicine ball throwing variables (p < 0.05). However, no statistically significant difference was discovered for the flexibility and sitting height variables (p > 0.05). The BMI, sitting height, and stroke length levels for the group with autism spectrum disorder were higher than the other groups, as the flexibility levels of the group with down syndrome were higher than the other groups. Students with intellectual disabilities were demonstrated to have better values than other groups regarding standing long jump and medicine ball throwing performances. Conclusions: Objective information about the physical fitness of individuals with children with different neurodevelopmental disabilities was obtained. In addition, the data obtained with these children will contribute to future plans for movement training as well as the content and frequency of the interventions, and will guide the development of new strategies to develop physical abilities and physical wellness.

Patterns and predictors of adaptive skills in 2- to 7-year-old children with Down syndrome

Background

There is substantial variability in adaptive skills among individuals with Down syndrome. Few studies, however, have focused on the early developmental period or on the potential sources of variability in adaptive skills. This study characterizes adaptive skills in young children with Down syndrome and investigates child characteristics associated with adaptive skills.

Methods

Participants were 44 children with Down syndrome ranging in age from 2.50 to 7.99 years (M = 4.66 years, SD = 1.46). The Vineland Adaptive Behavior Scales-3 (VABS-3) Comprehensive Interview Form was used to assess adaptive behavior in the three core domains: socialization, daily living, and communication skills. Caregivers also reported on motor skills and autism spectrum disorder symptoms. Child cognitive abilities were assessed.

Results

Analyses comparing mean standard score performance across the three VABS-3 core domains demonstrated significant differences between all pairs of domains, resulting in a group-level pattern of socialization > daily living > communication skills. At the individual level, 10 different patterns of relative strength and weakness were identified, with only 18% of participants evidencing significant differences between adaptive skill domain standard scores corresponding to the group-level pattern of significant differences. Child characteristics (cognitive abilities, motor skills, and autism spectrum disorder symptoms) were significantly associated with VABS-3 adaptive domain standard scores.

Conclusion

These findings underscore the importance of individualizing intervention programs focused on improving the adaptive skills of young children with Down syndrome based on consideration of the child’s relative adaptive strengths and weaknesses.

Gross motor dysfunction and balance impairments in children and adolescents with Down syndrome: a systematic review

BACKGROUND

Individuals with Down syndrome present with several impairments such as hypotonia, ligament laxity, decreased muscle strength, insufficient muscular cocontraction, inadequate postural control, and disturbed proprioception. These factors are responsible for the developmental challenges faced by children with Down syndrome. These individuals also present with balance dysfunctions.

PURPOSE

This systematic review aims to describe the motor dysfunction and balance impairments in children and adolescents with Down syndrome.

METHODS

We searched the Scopus, ScienceDirect, MEDLINE, Wiley, and EBSCO databases for observational studies evaluating the motor abilities and balance performance in individuals with Down syndrome. The review was registered on PROSPERO.

RESULTS

A total of 1,096 articles were retrieved; after careful screening and scrutinizing against the inclusion and exclusion criteria, 10 articles were included in the review. Overall, the children and adolescents with Down syndrome showed delays and dysfunction in performing various activities such as sitting, pulling to stand, standing, and walking. They also presented with compensatory mechanisms to maintain their equilibrium in static and dynamic activities.

CONCLUSION

The motor development of children with Down syndrome is significantly delayed due to structural differences in the brain. These individuals have inefficient compensatory strategies like increasing step width, increasing frequency of mediolateral center of pressure displacement, decreasing anteroposterior displacement, increasing trunk stiffness, and increasing posterior trunk displacement to maintain equilibrium. Down syndrome presents with interindividual variations; therefore, a thorough evaluation is required before a structured intervention is developed to improve motor and balance dysfunction.

A reassessment of Jackson's checklist and identification of two Down syndrome sub-phenotypes

Down syndrome (DS) is characterised by several clinical features including intellectual disability (ID) and craniofacial dysmorphisms. In 1976, Jackson and coll. identified a checklist of signs for clinical diagnosis of DS; the utility of these checklists in improving the accuracy of clinical diagnosis has been recently reaffirmed, but they have rarely been revised. The purpose of this work is to reassess the characteristic phenotypic signs and their frequencies in 233 DS subjects, following Jackson's checklist. 63.77% of the subjects showed more than 12 signs while none showed less than 5, confirming the effectiveness of Jackson's checklist for the clinical diagnosis of DS. An association between three phenotypic signs emerged, allowing us to distinguish two sub-phenotypes: Brachycephaly, short and broad Hands, short Neck (BHN), which is more frequent, and "non-BHN". The strong association of these signs might be interpreted in the context of the growth defects observed in DS children suggesting decreased cell proliferation. Lastly, cognitive assessments were investigated for 114 subjects. The lack of association between the presence of a physical sign or the number of signs present in a subject and cognitive skills disproves the stereotype that physical characteristics are predictive of degree of ID.

Social abilities in young Mexicans with Down syndrome during the COVID-19 pandemic

Background: Social abilities include interpersonal skills, interaction, and social responsibility. The nature of these abilities has not been explored in young people with Down syndrome (DS) during the social isolation of the COVID-19 pandemic. Method: The aim of this online study was to describe the social profile of a group of 30 Mexican people with DS, with a chronological age of 15-29 years, and explore the variables related to their psychosocial profiles. A sociodemographic questionnaire, mental age examination, and socialization battery were applied. Social behavior was analyzed in domains that facilitate socialization (leadership, joviality, social sensitivity, respect/self-control), in domains that disrupt socialization (aggressiveness/stubbornness, apathy/withdrawal, anxiety/shyness), and on a global scale. Results: Participants' scores in the facilitative domains were above average, and their scores in the disruptive domains were below average, as expected. Scores on the respect/self-control scale were associated with chronological age (CA), and those on the global scale with mental age (MA). Discussion: No impairments were found in the social skills of young people with DS according to the parameters of the scale. The development of the social profile with CA and MA stimulates cognition and promotes independence, autonomy, and proactivity. Parents' role in regulating children's behavior was an important factor in managing their social isolation during the COVID-19 pandemic.

Anxiety and Worries of Individuals with Down Syndrome During the COVID-19 Pandemic: A Comparative Study in the UK

The present study explored the effects of the pandemic on individuals with Down Syndrome (DS; n = 67) compared to other groups with Special Education Needs and Disabilities (SEND; n = 48) and their Typically Developing Siblings (TDS; n = 56). In total, 115 caregivers reported on their own anxiety and worries and of their children. Anxiety levels for individuals with DS appeared to be lower compared to other SEND populations and to TDS. In terms of worries, individuals with DS worried more about social-related worries but worried less about family-related aspects compared to the other groups. In sum, individuals with DS might show less anxiety but still worried more about specific aspects related to the impact of COVID-19 pandemic on their lives.

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.

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.

[Formula: see text] The role of distinct executive functions on adaptive behavior in children and adolescents with Down syndrome

Difficulties in executive function are a relatively well-characterized feature of the neuropsychological profile in Down syndrome (DS), yet the impact of these challenges on aspects of daily functioning remain poorly understood. We examined the role of specific executive functions on domains of adaptive behavior in children and adolescents with DS. Participants included 68 children and adolescents with DS between 6-17 years old (mean chronological age = 12.56 years; SD = 3.22) and their caregivers. Parent reported executive function skills were measured using the BRIEF-2 and adaptive behavior was measured using the Vineland Adaptive Behavior Scales-III. Results identified working memory as a significant predictor of Communication, Daily Living, and Socialization skills, and Shifting significantly predicted Daily Living and Socialization. Findings demonstrate the relation between executive functions and adaptive behavior and highlight the effects of working memory on aspects of daily functioning for individuals with DS.

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.

Subclinical Hypothyroidism as the Most Common Thyroid Dysfunction Status in Children With Down's Syndrome

INTRODUCTION

Thyroid dysfunctions are one of the most common abnormalities coexisting in children with Down's syndrome (DS) and have been reported in up to 54% of cases.

AIM OF THE STUDY

The purposes of this retrospective study were to investigate the course of subclinical hypothyroidism in children with DS, to evaluate the thyroid function of these subjects in relation to the risk of developing overt thyroid disease and autoimmunity, and to identify clinical and biochemical characteristics of patients prescribed L-T4 therapy in children and adolescents with DS and SH.

MATERIAL AND METHODS

The records of DS patients referred to the Endocrinology Outpatient Clinic between 2010 and 2015 for screening of thyroid function were observed till the end of 2019 June and analyzed retrospectively. The children diagnosed with congenital hypothyroidism, acute lymphoblastic leukemia, and seizures and treated with drugs that may have interfered with thyroid function like lithium, antiepileptic, or iodinated drugs and glucocorticoids were excluded from the study.

RESULTS

The data of 77 DS patients were collected, evaluated, and analyzed. The study group consisted of 73 patients (32 girls and 41 boys with the mean age at baseline of 3.0 ± 4.5 years). A total of 63/73 (87%) children were diagnosed with SH. The 16/63 (25.4%) patients were followed-up without the treatment (group SH-T0), and therapy with levothyroxine (L-T4) was introduced in 47/63 (74.6%) SH children with a mean dosage of 1.8 ± 1.0 μg/kg/day (group SH-T1). Thyroxine supplementation did not improve growth expressed as ΔhSDS (0.1 ± 1.3, ranged -2.1 to 3.8 in SH-T0 vs. 0.0 ± 0.7, ranged -1.7 to 1.4 in SH-T1, p = 0.96) and ΔBMI Z-score (0.3 ± 0.9, ranged -0.9 to 2.6 in SH-T0 vs. 0.3 ± 1.1, ranged -2.1 to 2.9 in SH-T1, p = 0.65). Positive anti-TPO and anti-TG antibodies were detected in 7/63 (11.1%) DS cases.

CONCLUSIONS

SH is the most frequent presentation of thyroid gland dysfunction in DS children. A small percentage of patients develop an overt hypothyroidism, particularly in females with mostly positive titer of antithyroid autoantibodies.

Executive function in down syndrome children in Bogotá, Colombia

The study aim was to characterize executive function in 114 children with Down syndrome from a reference institution in Bogotá, Colombia. Children were screened with the Battelle Developmental Inventory to establish their developmental age. Eighty children with an equivalent mental age of 2–5.11 years were allocated to groups of 20 according to their mental age. Parents and teachers then completed the Behavior Rating Inventory of Executive Function-Preschool Version. We found a high variability and a low correlation between parent and teacher ratings. In general, children showed a specific profile characterized by weakness in the domains of working memory, shifting, planning, and organization, and strengths in the emotional control domain. These findings indicate a characteristic pattern of executive function in children with Down syndrome. This profile could form the basis for the planning of clinical assessment programs.

In-Home Mobility Training With a Portable Body Weight Support System of an Infant With Down Syndrome

PURPOSE

To report on the feasibility of an open-area, portable body weight support system (PBWSS) for in-home use and overground mobility training in an infant with Down syndrome.

SUMMARY OF KEY POINTS

The family used the PBWSS on average 4 days/week and for a mean duration of 27.9 minutes/day. Within sessions, the infant's mobility in the open area was greater with PBWSS assistance. The infant's mobility increased whereas variable trends were noted in the infant's motor, language, and cognitive development.

CONCLUSIONS

The long-term and frequent use of the PBWSS by this family provided opportunities to practice on emerging motor skills and exploratory actions that may have had a positive effect on her mobility and overall development.

RECOMMENDATION FOR CLINICAL PRACTICE

High-dose, body weight-supported training on emerging motor skills is feasible in the infants' natural environments. Future studies using a large sample will quantify the effects.

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.

Epileptic spasms in individuals with Down syndrome: A review of the current literature

Epilepsy can occur in individuals with Down syndrome (DS), with epileptic spasms representing the most frequent seizure type in this population. Epileptic spasms can have devastating consequences on the development of individuals with the condition. This review sought to explore the lifetime prevalence and underlying mechanism of epileptic spasms in this population. We also aimed to review the response rate to various treatments, the relapse rate, and the development of subsequent epilepsy or autism in this population. A comprehensive literature search was conducted for articles discussing the lifetime prevalence, diagnosis, treatment, outcomes, or underlying etiology of epileptic spasms in animal models or individuals with DS. According to available literature, the global clinic-based lifetime prevalence of epilepsy in individuals with DS ranged from 1.6% to 23.1%, with epileptic spasms representing 6.7%-66.7% of these cases. Response rate to treatment with adrenocorticotropic hormone/corticosteroids was highest (81%) and has the most literature supporting its use, with other regimens, including vigabatrin and other antiepileptic drugs, having lower response rates. Epileptic spasms occur more frequently in children with DS than in the general population, though more studies are needed to determine the true lifetime prevalence of epileptic spasms in this population. Generally, children with DS and epileptic spasms tend to be more responsive to treatment and have better outcomes than children with epileptic spasms of unknown etiology (ie, without DS), in terms of response and relapse rates as well as the development of intractable epilepsy (eg, Lennox-Gastaut syndrome).

Systematic Review of Recent Pediatric Down Syndrome Neuropsychology Literature: Considerations for Regression Assessment and Monitoring

OBJECTIVES

To conduct a systematic review of recent pediatric Down syndrome (DS) neuropsychology research that may be useful to clinicians and researchers examining regression in this population.

METHODS

We reviewed original peer-reviewed articles published between 2013 and 2018 studying neuropsychological profiles in DS.

RESULTS

Thirty-one articles (of 1231 included in the original search) passed all inclusion criteria, were evaluated for bias, and were included in the analysis.

CONCLUSION

Findings argued against a single "DS profile" and revealed multiple within-group differences as well as expected and unexpected differences relative to typically developing children and children with other intellectual and developmental disabilities. Areas identified as most germane to regression monitoring included working memory, inhibition, letter and word identification, navigational route learning, motor skills (when strong at baseline), single word receptive/expressive vocabulary, and adaptive function.

Plasma metabolome and cognitive skills in Down syndrome

Trisomy 21 (Down syndrome, DS) is the main human genetic cause of intellectual disability (ID). Lejeune hypothesized that DS could be considered a metabolic disease, and we found that subjects with DS have a specific plasma and urinary metabolomic profile. In this work we confirmed the alteration of mitochondrial metabolism in DS and also investigated if metabolite levels are related to cognitive aspects of DS. We analyzed the metabolomic profiles of plasma samples from 129 subjects with DS and 46 healthy control (CTRL) subjects by 1H Nuclear Magnetic Resonance (NMR). Multivariate analysis of the NMR metabolomic profiles showed a clear discrimination (up to 94% accuracy) between the two groups. The univariate analysis revealed a significant alteration in 7 metabolites out of 28 assigned unambiguously. Correlations among the metabolite levels in DS and CTRL groups were separately investigated and statistically significant relationships appeared. On the contrary, statistically significant correlations among the NMR-detectable part of DS plasma metabolome and the different intelligence quotient ranges obtained by Griffiths-III or WPPSI-III tests were not found. Even if metabolic imbalance provides a clear discrimination between DS and CTRL groups, it appears that the investigated metabolomic profiles cannot be associated with the degree of ID.

Multiorgan involvement and management in children with Down syndrome

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Down syndrome and parental depression: A double hit on early expressive language development

BACKGROUND AND AIMS

Down syndrome (DS) is often characterised by intellectual disability with particular difficulties in expressive language. However, large individual differences exist in expressive language across development in DS. In the general population, one of the factors associated with variability in this domain is parental depression. We investigated whether this is also the case in young children with DS.

METHODS

Thirty-eight children with DS between 8 and 48 months of age participated in this study. Their parents reported on the children's receptive and expressive vocabularies (MacArthur-Bates Communicative Development Inventory) and on parental depression. Furthermore, an experimenter-led standardized developmental assessment (Mullen Scales of Early Learning) was administered to the children to test five domains: gross motor, fine motor, visual reception, receptive language, and expressive language.

RESULTS

A cross-sectional developmental trajectories analysis demonstrated that expressive language developed at a slower rate in children with DS whose parent reported depression than in those whose parent did not. No differences between groups were found in any other domain.

CONCLUSION

Parental depression is associated with slower rate of expressive language development in young children with DS. These findings suggest that DS and parental depression may constitute a double hit leading to increased difficulties in the development of expressive language.

Developmental Support for Infants With Genetic Disorders

As the technical ability for genetic diagnosis continues to improve, an increasing number of diagnoses are made in infancy or as early as the neonatal period. Many of these diagnoses are known to be associated with developmental delay and intellectual disability, features that would not be clinically detectable at the time of diagnosis. Others may be associated with cognitive impairment, but the incidence and severity are yet to be fully described. These neonates and infants with genetic diagnoses therefore represent an emerging group of patients who are at high risk for neurodevelopmental disabilities. Although there are well-established developmental supports for high-risk infants, particularly preterm infants, after discharge from the NICU, programs specifically for infants with genetic diagnoses are rare. And although previous research has demonstrated the positive effect of early developmental interventions on outcomes among preterm infants, the impact of such supports for infants with genetic disorders who may be born term, remains to be understood. We therefore review the literature regarding existing developmental assessment and intervention approaches for children with genetic disorders, evaluating these in the context of current developmental supports postdischarge for preterm infants. Further research into the role of developmental support programs for early assessment and intervention in high-risk neonates diagnosed with rare genetic disorders is needed.

Challenges and Opportunities for Translation of Therapies to Improve Cognition in Down Syndrome

While preclinical studies have reported improvement of behavioral deficits in the Ts65Dn mouse model of Down syndrome (DS), translation to human clinical trials to improve cognition in individuals with DS has had a poor success record. Timing of the intervention, choice of animal models, strategy for drug selection, and lack of translational endpoints between animals and humans contributed to prior failures of human clinical trials. Here, we focus on in vitro cell models from humans with DS to identify the molecular mechanisms underlying the brain phenotype associated with DS. We emphasize the importance of using these cell models to screen for therapeutic molecules, followed by validating them in the most suitable animal models prior to initiating human clinical trials.

Role of Social and Informational Support while Deciding on Pregnancy Termination for Medical Reasons

Background: Poland is a country with restrictive laws concerning abortion, which is only allowed if the mother’s life and health are in danger, in case of rape, and severe defects in the fetus. This paper specifies the forms of support expected by women considering termination from their family, people in their surroundings and professional medical personnel. Methods: Between June 2014 and May 2016 patients eligible to terminate a pregnancy for medical reasons were asked to complete an anonymous survey consisting of sixty questions to determine patient profile and forms of support expected from the society, family and professional medical personnel as well as to assess informational support provided. Results: Women do not take into consideration society’s opinion on pregnancy termination (95%). The majority of the respondents think that financial support from the state is not sufficient to provide for sick children (81%). Despite claiming to have a medium standard of life (75%), nearly half of the respondents (45%) say that they do not have the financial resources to take care of a sick child. The women have informed their partner (97%) and closest family members (82%) and a low percentage have informed friends (32%). Nearly one third (31%) have not talked to the attending gynecologist about their decision. Conclusions: The decision to terminate a pregnancy is made by mature women with a stable life situation—supported by their partner and close family. They do not expect systemic support, as they believe it is marginal, and only seek emotional support from their closest family. They appreciate support provided by professional medical personnel if it is personal.

Gross motor proficiency and intellectual functioning: A comparison among children with Down syndrome, children with borderline intellectual functioning, and typically developing children

This cross-sectional study examines differences in gross motor proficiency as a function of different intellectual functioning profiles. Two motor areas have been investigated as being equally essential to gross motor functions in every-day life: locomotion and object control.It aims to compare gross motor skills endorsed by children with Down syndrome (DS), children with borderline intellectual functioning (BIF), and typically developing children (TDC).Group 1 was composed of 18 children with DS (chronological age = 8.22), group 2 was composed of 18 children with BIF (chronological age = 9.32), and group 3 was composed of 18 children with typical development (TD) (chronological age = 9.28).Gross motor skills were measured through the test of gross motor development (TGMD-Test) composed of locomotion and object control tasks.Children with DS showed worse gross motor skills compared with children with BIF and typically developing children by underscoring both on all locomotion (e.g., walking, running, hopping, galloping, jumping, sliding, and leaping) and all object control tasks (e.g., throwing, catching, striking, bouncing, kicking, pulling, and pushing).In DS group strengths were found on run and slide skills, in BIF group strengths were on run, long jump and slide skills and in TDC group strengths were on run and slide skills. For all of the 3 groups the locomotor worst performed task was jump forward with arm swing.Findings suggest implications for further practice to develop evidence-based exercise programs aimed to rehabilitate gross motor skills through the regular participation in structured exercise activities.

Correction of cognitive deficits in mouse models of Down syndrome by a pharmacological inhibitor of DYRK1A

Growing evidence supports the implication of DYRK1A in the development of cognitive deficits seen in Down syndrome (DS) and Alzheimer's disease (AD). We here demonstrate that pharmacological inhibition of brain DYRK1A is able to correct recognition memory deficits in three DS mouse models with increasing genetic complexity [Tg(Dyrk1a), Ts65Dn, Dp1Yey], all expressing an extra copy of Dyrk1a Overexpressed DYRK1A accumulates in the cytoplasm and at the synapse. Treatment of the three DS models with the pharmacological DYRK1A inhibitor leucettine L41 leads to normalization of DYRK1A activity and corrects the novel object cognitive impairment observed in these models. Brain functional magnetic resonance imaging reveals that this cognitive improvement is paralleled by functional connectivity remodelling of core brain areas involved in learning/memory processes. The impact of Dyrk1a trisomy and L41 treatment on brain phosphoproteins was investigated by a quantitative phosphoproteomics method, revealing the implication of synaptic (synapsin 1) and cytoskeletal components involved in synaptic response and axonal organization. These results encourage the development of DYRK1A inhibitors as drug candidates to treat cognitive deficits associated with DS and AD.

Lifespan analysis of brain development, gene expression and behavioral phenotypes in the Ts1Cje, Ts65Dn and Dp(16)1/Yey mouse models of Down syndrome

Down syndrome (DS) results from triplication of human chromosome 21. Neuropathological hallmarks of DS include atypical central nervous system development that manifests prenatally and extends throughout life. As a result, individuals with DS exhibit cognitive and motor deficits, and have delays in achieving developmental milestones. To determine whether different mouse models of DS recapitulate the human prenatal and postnatal phenotypes, here, we directly compared brain histogenesis, gene expression and behavior over the lifespan of three cytogenetically distinct mouse models of DS: Ts1Cje, Ts65Dn and Dp(16)1/Yey. Histological data indicated that Ts65Dn mice were the most consistently affected with respect to somatic growth, neurogenesis and brain morphogenesis. Embryonic and adult gene expression results showed that Ts1Cje and Ts65Dn brains had considerably more differentially expressed (DEX) genes compared with Dp(16)1/Yey mice, despite the larger number of triplicated genes in the latter model. In addition, DEX genes showed little overlap in identity and chromosomal distribution in the three models, leading to dissimilarities in affected functional pathways. Perinatal and adult behavioral testing also highlighted differences among the models in their abilities to achieve various developmental milestones and perform hippocampal- and motor-based tasks. Interestingly, Dp(16)1/Yey mice showed no abnormalities in prenatal brain phenotypes, yet they manifested behavioral deficits starting at postnatal day 15 that continued through adulthood. In contrast, Ts1Cje mice showed mildly abnormal embryonic brain phenotypes, but only select behavioral deficits as neonates and adults. Altogether, our data showed widespread and unexpected fundamental differences in behavioral, gene expression and brain development phenotypes between these three mouse models. Our findings illustrate unique limitations of each model when studying aspects of brain development and function in DS. This work helps to inform model selection in future studies investigating how observed neurodevelopmental abnormalities arise, how they contribute to cognitive impairment, and when testing therapeutic molecules to ameliorate the intellectual disability associated with DS.This article has an associated First Person interview with the first author of the paper.

Behavioral Problems and Psychosocial Strengths: Unique Factors Contributing to the Behavioral Profile of Youth With Down Syndrome

This study aimed to describe problem behaviors and psychosocial strengths, examine the problem-strength interrelations, and evaluate profiles of problems and strengths in youth with Down syndrome (DS). The community-based sample consisted of 67 parents of children with DS aged between 4 and 19 years. Parents reported about the developmental age (Vineland screener), behavioral problems (Child Behavior Checklist), and psychosocial strengths (Behavioral and Emotional Rating Scale) of their child. Results indicate that attention, social, and thought problems were most prevalent, whereas family involvement and receiving/expressing affection were identified as strengths. A confirmatory factor analysis identified problems and strengths as distinct, yet related, variables. Moreover, a cluster analysis of problems and strengths identified four different profiles. Implications for interventions are discussed.

Using computational support in motor ability analysis of individuals with Down syndrome: Literature review

BACKGROUND

The lack of motor ability is one of the main Down syndrome (DS) effects. However, there are several types of motor disorders that can be attenuated or corrected if they are early identified and properly analyzed.

OBJECTIVES

The aim of our study is to support the local Physical Activity research group, which works with about 25 DS children, by means of computational resources for motor analysis. To that end, we first needed to identify the main computational approaches that support the motor analysis of DS individuals, if they are already connected to intervention programs, and potential opportunities to extend the current state of the art.

METHOD

We carried out a systematic review that identified 28 papers from the current literature. These papers were then analyzed to answer the research questions defined in our study.

RESULTS

Our main findings were: (1) the temporal distribution of papers shows this area is new and it is starting to create a body of knowledge that in fact supports motor treatments of DS individuals; (2) there is a diversity of studies that consider different research directions such as comparisons of motor features of DS with non-DS individuals, characterization of DS motor features, and approaches for intervention programs to improve DS motor abilities; (3) there are several types of sensing hardware that enables the development of studies from different perspectives; (4) spatial monitoring is performed but only in laboratory conditions; (5); mathematical tools are largely used while strategies based on artificial intelligence for automated analysis are ignored; and (6) proposals for DS post-intervention monitoring are not found in the literature.

CONCLUSION

DS motor analysis is still a new research area and it is not mature yet. Thus, the use of computational resources is very pragmatic and focused only on mathematical tools that support the numerical analysis of the acquired data. The main proposals for motor analysis are performed in laboratory, so that there are several opportunities to create computational resources to obtain real-time data on the move. The integration of this data with intervention strategies is also a potential area for future researches.

Developmental trend of children with Down's syndrome - How do sex and neonatal conditions influence their developmental patterns?

OBJECTIVE

This study investigated factors that would influence developmental trend of children with Down's syndrome (DS) in three different domains (motor, cognitive, language), specifically focusing on the effect of sex and neonatal conditions, including preterm birth, low birth weight, and congenital heart disease (CHD).

METHODS

The participants were 158 children with DS (mean age at the initial test = 25.5 months) receiving clinical service at a rehabilitation center in Yokohama, Japan. Kyoto Scale of Psychological Development was used to measure developmental level, which derive total developmental age (DA), Posture-motor DA, Cognitive-adaptive DA, and Language-social DA. For the analyses, a multilevel model for change was adopted, as the model allowed us to investigate intrapersonal growth and the between-personal factors that are associated with individual differences in the pattern of growth.

RESULTS

The developmental speed of children with DS was found to be slower than that of typical children in all the three developmental domains assessed (i.e., the estimated coefficient of the slope for chronological age on DA was less than 1). DS Girls developed significantly faster than boys in non-verbal cognitive and language abilities. Low birth weight and CHD had a significant negative impact on development of non-verbal cognitive abilities for boys, but had a somewhat positive effect for girls.

CONCLUSION

As was shown in previous studies, the result of this study indicated that the children with DS develop slower than non-disabled children. Low birth weight and CHD were found to influence developmental trend of children with DS, differently for boys and girls.

A third copy of the Down syndrome cell adhesion molecule (Dscam) causes synaptic and locomotor dysfunction in Drosophila

Down syndrome (DS) is caused by triplication of chromosome 21 (HSA21). It is characterised by intellectual disability and impaired motor coordination that arise from changes in brain volume, structure and function. However, the contribution of each HSA21 gene to these various phenotypes and to the causal alterations in neuronal and synaptic structure and function are largely unknown. Here we have investigated the effect of overexpression of the HSA21 gene DSCAM (Down syndrome cell adhesion molecule), on glutamatergic synaptic transmission and motor coordination, using Drosophila expressing three copies of Dscam1. Electrophysiological recordings of miniature and evoked excitatory junction potentials at the glutamatergic neuromuscular junction of Drosophila larvae showed that the extra copy of Dscam1 changed the properties of spontaneous and electrically-evoked transmitter release and strengthened short-term synaptic depression during high-frequency firing of the motor nerve. Behavioural analyses uncovered impaired locomotor coordination despite preserved gross motor function. This work identifies DSCAM as a candidate causative gene in DS that is sufficient to modify synaptic transmission and synaptic plasticity and cause a DS behavioural phenotype.

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Drosophila expressing a third copy of Dscam have altered neuromuscular transmission.

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Drosophila expressing a third copy of Dscam have deficits in locomotor coordination.

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Drosophila are a powerful system for studying single-gene effects in Down syndrome.