The importance of understanding individual differences in Down syndrome

Developing a screening instrument for underlying core domains of communicative competence in children with communication support needs

A socio-neurocognitive approach to augmentative and alternative communication (AAC) shows several underlying domains of communicative competence: Attention, perception, cognition, memory, orientation, socio-emotional development, motor skills, and language. To determine developmental markers of these underlying core domains of communicative competence in children with communication support needs, we developed a new screening instrument. The present article consists of three consecutive studies. In study 1, we constructed the first version of the screening instrument based on a sample of both children without disabilities and children with Down syndrome. In study 2, we confirmed the reliability (i.e., internal consistency) of the screening instrument in a new group of young children with typical development and established concurrent validity with the Early Language Scale. In study 3, we established concurrent validity with the Communication Matrix in a clinical sample of children with communication support needs. The screening instrument can be used in clinical practice as part of AAC assessment to provide comprehensive insights into strengths and weaknesses in the underlying core domains of communicative competence of children with communication support needs.

The Feasibility of an Online Language Program Delivered Through Music and the Impact of Dosage on Vocabulary Outcomes in Young Children With Down Syndrome

BACKGROUND

Few studies have explored the feasibility of online language interventions for young children with Down syndrome. Additionally, none have manipulated dose frequency or reported on the use of music as a medium through which language and sign can be learned.

PURPOSE

The purpose of this study was to (a) examine the feasibility and acceptability of an online language through music intervention for young children (1-3;6 years) with Down syndrome and (b) compare effectiveness at two intervention dose frequencies.

METHOD

The study was carried out in two phases using a mixed-methods design. Phase 1: Qualitative data were gathered from parents to examine feasibility when implementing a video-based language intervention. Phase 2: Seventy-six families participated in an online language intervention at home. Effectiveness was examined comparing two groups, randomly assigned to a high and low dose frequency. The Down Syndrome Education (DSE) checklists (combined) were the primary outcome measure. Process data were gathered to determine intervention acceptability in practice and to identify factors that would improve successful future implementation. Acceptability data were analyzed with reference to the theoretical framework of acceptability (Version 2).

RESULTS

Forty-three parents completed the Phase 1 scoping questionnaire, five of whom took part in focus groups. Once weekly morning sessions were indicated as the preferred scheduling choice. Phase 2 quantitative data were analyzed using beta regression adjusted for baseline scores and indicated no additional benefit to receiving the higher dose. However, exploratory interaction models suggested that the efficacy of the high-dose intervention was higher (than low-dose intervention) in participants with higher baseline DSE performance. Parents perceived the intervention to be effective and positive for the family.

CONCLUSION

The results add to our knowledge of real-world effective online interventions and suggest that a critical minimum language level is required for children with Down syndrome to benefit optimally from a higher intervention dose frequency.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25979704.

Spatial exploration and navigation in Down syndrome and Williams syndrome

We know little about the ability to explore and navigate large-scale space for people with intellectual disability (ID). In this cross-syndrome study, individuals with Down syndrome (DS), individuals with Williams syndrome (WS) and typically developing children (TD; aged 5-11 years) explored virtual environments with the goal of learning where everything was within the environment (Experiment 1) or to find six stars (Experiment 2). There was little difference between the WS and DS groups when the goal was simply to learn about the environment with no specific destination to be reached (Experiment 1); both groups performed at a level akin to a subset of TD children of a similar level of non-verbal ability. The difference became evident when the goal of the task was to locate targets in the environment (Experiment 2). The DS group showed the weakest performance, performing at or below the level of a subset of TD children at a similar level of non-verbal ability, whilst the WS group performed at the level of the TD subset group. The DS, WS and TD group also demonstrated different patterns of exploration behavior. Exploration behaviour in DS was weak and did not improve across trials. In WS, exploration behavior changed across trials but was atypical (the number of revisits increased with repeated trials). Moreover, transdiagnostic individual difference analysis (Latent Profile Analysis) revealed five profiles of exploration and navigation variables, none of which were uniquely specific to DS or to WS. Only the most extreme profile of very poor navigators was specific to participants with DS and WS. Interestingly, all other profiles contained at least one individual with DS and at least one individual with WS. This highlights the importance of investigating heterogeneity in the performance of individuals with intellectual disability and the usefulness of a data-driven transdiagnostic approach to identifying behavioral profiles.

Superoxide dismutase and neurological disorders

Superoxide dismutase (SOD) is a common antioxidant enzyme found majorly in living cells. The main physiological role of SOD is detoxification and maintain the redox balance, acts as a first line of defence against Reactive nitrogen species (RNS), Reactive oxygen species (ROS), and other such potentially hazardous molecules. SOD catalyses the conversion of superoxide anion free radicals (O 2 -.) into molecular oxygen (O 2) and hydrogen peroxide (H 2O 2) in the cells. Superoxide dismutases (SODs) are expressed in neurons and glial cells throughout the CNS both intracellularly and extracellularly. Endogenous oxidative stress (OS) linked with enlarged production of reactive oxygen metabolites (ROMs), inflammation, deregulation of redox balance, mitochondrial dysfunction and bioenergetic crisis are found to be prerequisite for neuronal loss in neurological diseases. Clinical and genetic studies indicate a direct correlation between mutations in SOD gene and neurodegenerative diseases, like Amyotrophic Lateral Sclerosis (ALS), Huntington's disease (HD), Parkinson's Disease (PD) and Alzheimer's Disease (AD). Therefore, inhibitors of OS are considered as an optimistic approach to prevent neuronal loss. SOD mimetics like Metalloporphyrin Mn (II)-cyclic polyamines, Nitroxides and Mn (III)- Salen complexes are designed and used as therapeutic extensively in the treatment of neurological disorders. SODs and SOD mimetics are promising future therapeutics in the field of various diseases with OS-mediated pathology.

Age of Alzheimer's disease diagnosis in people with Down syndrome and associated factors: Results from the Horizon 21 European Down syndrome consortium

INTRODUCTION

People with Down syndrome (DS) have high risk of developing Alzheimer's disease (AD). This study examined mean ages of AD diagnosis and associations with co-occurring conditions among adults with DS from five European countries.

METHODS

Data from 1335 people with DS from the Horizon 21 European DS Consortium were used for the analysis.

RESULTS

Mean ages of AD diagnosis ranged between 51.4 (SD 7.0) years (United Kingdom) and 55.6 (SD 6.8) years (France). Sleep-related and mental health problems were associated with earlier age of AD diagnosis. The higher number of co-occurring conditions the more likely the person with DS is diagnosed with AD at an earlier age.

DISCUSSION

Mean age of AD diagnosis in DS was relatively consistent across countries. However, co-occurring conditions varied and impacted on age of diagnosis, suggesting that improvements can be made in diagnosing and managing these conditions to delay onset of AD in DS.

HIGHLIGHTS

Mean age of AD diagnosis was relatively consistent between countries Sleep problems and mental health problems were associated with earlier age of AD diagnosis APOE ε4 carriers were diagnosed with AD at an earlier age compared to non-carriers Number of co-occurring conditions was associated with earlier age of AD diagnosis No differences between level of intellectual disability and mean age of AD diagnosis.

Low TGF-β1 plasma levels are associated with cognitive decline in Down syndrome

Almost all individuals with Down's syndrome (DS) show the characteristic neuropathological features of Alzheimer's disease (AD) by the age of 40, yet not every individual with DS experiences symptoms of AD later in life. Similar to neurotypical developing subjects, AD in people with DS lasts for a long preclinical phase in which biomarkers follow a predictable order of changes. Hence, a prolonged asymptomatic period precedes the onset of dementia, underscoring the importance of identifying new biomarkers for the early detection and monitoring of cognitive decline in individuals with DS. Blood-based biomarkers may offer an alternative non-invasive strategy for the detection of peripheral biological alterations paralleling nervous system pathology in an early phase of the AD continuum. In the last few years, a strong neurobiological link has been demonstrated between the deficit of transforming growth factor-β1 (TGF-β1) levels, an anti-inflammatory cytokine endowed with neuroprotective activity, and early pro-inflammatory processes in the AD brain. In this clinical prospective observational study, we found significant lower plasma TGF-β1 concentrations at the first neuropsychological evaluation (baseline = T0) both in young adult DS individuals (19-35 years) and older DS subjects without AD (35-60 years) compared to age- and sex-matched healthy controls. Interestingly, we found that the lower TGF-β1 plasma concentrations at T0 were strongly correlated with the following cognitive decline at 12 months. In addition, in young individuals with DS, we found, for the first time, a negative correlation between low TGF-β1 concentrations and high TNF-α plasma concentrations, a pro-inflammatory cytokine that is known to be associated with cognitive impairment in DS individuals with AD. Finally, adopting an ex vivo approach, we found that TGF-β1 concentrations were reduced in parallel both in the plasma and in the peripheral blood mononuclear cells (PBMCs) of DS subjects, and interestingly, therapeutic concentrations of fluoxetine (FLX) applied to cultured PBMCs (1 µM for 24 h) were able to rescue TGF-β1 concentrations in the culture media from DS PBMCs, suggesting that FLX, a selective serotonin reuptake inhibitor (SSRI) endowed with neuroprotective activity, might rescue TGF-β1 concentrations in DS subjects at higher risk to develop cognitive decline.

Associations Among Sex, Cognitive Ability, and Autism Symptoms in Individuals with Down Syndrome

This study explores sex-differences in (a) rates and profiles of autism symptoms as well as in (b) the contribution of intellectual quotient (IQ) to autism symptom presentation in Down syndrome (DS). Participants were 40 males and 38 females with DS, aged 6 to 23 years. Autism symptoms were rated through the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2). Results show no sex differences in the ADOS-2 Calibrated Severity Scores (CSS). However, only females with DS who are classified as DS-Only have higher scores on verbal IQ than those classified as DS + autism. Furthermore, associations between IQ and all CSSs are found for females, but not for males. Findings suggest that verbal cognition may play differential roles for females and males with 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.

Prevalence of bruxism in down syndrome patients: A systematic review and meta-analysis

BACKGROUND

Bruxism is a parafunctional activity characterised by grinding or clenching of teeth and is a common oral health concern in individuals with down syndrome (DS). Understanding the prevalence of bruxism in this population is crucial for developing effective management strategies. This systematic review and meta-analysis is aimed to investigate the prevalence of bruxism among individuals with DS and explore its association with other oral health issues.

METHODS

A comprehensive search was conducted across multiple electronic databases to identify relevant studies. Cross-sectional and observational studies were included. Data on bruxism prevalence and associated factors were extracted, and a meta-analysis was performed using both fixed-effects (FE) and random-effects (RE) models of MedCalc software. Heterogeneity among studies was assessed using I2 statistics. New Castle-Ottawa Scale was used to evaluate methodological quality of the included studies.

RESULTS

Eight studies met the pre-defined inclusion criteria and were included in the analysis. Seven studies used a questionnaire to assess bruxism. The pooled proportion estimate for occurrence of DS across the included studies was found to be 0.33 (95% CI: 0.22-0.45) as per the RE model and 0.35 (95% CI: 0.31-0.450) as per FE model in the quantitative analysis. All studies exhibited good methodological quality.

CONCLUSION

This systematic review and meta-analysis provide evidence of a significant prevalence of bruxism among individuals with DS. The findings highlight the association of bruxism with other oral health issues and specific chromosomal abnormalities. Comprehensive oral health assessments, including diagnostic procedures like Polysomnography, are essential for addressing the unique oral health needs of individuals with DS. Further studies are recommended with a valid tool for the diagnosis. Early interventions and management strategies need to be tailored to this population, considering the multifaceted nature of oral health concerns in individuals with DS.

Stuttering in individuals with Down syndrome: a systematic review of earlier research

The main objective of this systematic review was to synthesize the evidence on the occurrence and characteristics of stuttering in individuals with Down syndrome and thus contribute knowledge about stuttering in this population. Group studies reporting outcome measures of stuttering were included. Studies with participants who were preselected based on their fluency status were excluded. We searched the Eric, PsychInfo, Medline, Scopus, and Web of Science Core Collection databases on 3rd January 2022 and conducted supplementary searches of the reference lists of previous reviews and the studies included in the current review, as well as relevant speech and language journals. The included studies were coded in terms of information concerning sample characteristics, measurement approaches, and stuttering-related outcomes. The appraisal tool for cross-sectional studies (AXIS) was used to evaluate study quality. We identified 14 eligible studies, with a total of 1,833 participants (mean = 131.29, standard deviation = 227.85, median = 45.5) between 3 and 58 years of age. The estimated occurrence of stuttering ranged from 2.38 to 56%, which is substantially higher than the estimated prevalence (1%) of stuttering in the general population. The results also showed that stuttering severity most often was judged to be mild-to-moderate and that individuals with Down syndrome displayed secondary behaviors when these were measured. However, little attention has been paid to investigating the potential adverse effects of stuttering for individuals with Down syndrome. We judged the quality of the evidence to be moderate-to-low. The negative evaluation was mostly due to sampling limitations that decreased the representability and generalizability of the results. Based on the high occurrence of stuttering and the potential negative effects of this condition, individuals with Down syndrome who show signs of stuttering should be referred to a speech and language pathologist for an evaluation of their need for stuttering treatment.

Comprehensive volumetric phenotyping of the neonatal brain in Down syndrome

Down syndrome (DS) is the most common genetic cause of intellectual disability with a wide range of neurodevelopmental outcomes. To date, there have been very few in vivo neuroimaging studies of the neonatal brain in DS. In this study we used a cross-sectional sample of 493 preterm- to term-born control neonates from the developing Human Connectome Project to perform normative modeling of regional brain tissue volumes from 32 to 46 weeks postmenstrual age, accounting for sex and age variables. Deviation from the normative mean was quantified in 25 neonates with DS with postnatally confirmed karyotypes from the Early Brain Imaging in DS study. Here, we provide the first comprehensive volumetric phenotyping of the neonatal brain in DS, which is characterized by significantly reduced whole brain, cerebral white matter, and cerebellar volumes; reduced relative frontal and occipital lobar volumes, in contrast with enlarged relative temporal and parietal lobar volumes; enlarged relative deep gray matter volume (particularly the lentiform nuclei); and enlargement of the lateral ventricles, amongst other features. In future, the ability to assess phenotypic severity at the neonatal stage may help guide early interventions and, ultimately, help improve neurodevelopmental outcomes in children with DS.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

Using the Social Skills Improvement System (SSiS) Rating Scales to assess social skills in youth with Down syndrome

Introduction and Methods

This study provides preliminary data on the Social Skills Improvement System (SSiS) Rating Scales Parent Form to measure social skills in a sample of 124 children and adolescents with Down syndrome (DS) ages 6–17 years.

Results

Overall, participants demonstrated relatively mild symptoms, with the sample’s average standard score falling within 1 standard deviation from the mean of the normative sample for the social skills (M = 92, SD = 15) and problem behaviors (M = 104, SD = 12) domains (normative sample M = 100, SD = 15 for both domains). However, a wide range of scores was observed across the sample for the composite and subscale scores. Differential patterns were also observed by subscale. For some subscales (i.e., Cooperation, Assertion, Responsibility, Engagement, Externalizing, Hyperactivity/Inattention, and Autism Spectrum), a disproportionate number of participants scored in the below average (i.e., lower levels of social skills) or above average (i.e., more symptomatic in problem behaviors or autism spectrum) range relative to the normative sample; for other subscales (i.e., Communication, Empathy, Self-Control, Bullying, and Internalizing), participants’ score distribution aligned more closely to that of the normative sample. SSiS composite scores correlated in the expected directions with standardized measures of autism characteristics, executive function, and expressive language.

Discussion

This study provides some of the first evidence validating the use of the SSiS in youth with DS, filling a gap in standardized measures of social functioning in this population.

The Relationship between Teachers and Pupils with Down Syndrome: A Qualitative Study in Primary Schools

Down syndrome (DS), due the presence of an intellectual disability and a precarious health condition, involves important challenges for developing skills at school. The study explores the relational dynamics between teachers and students with DS and how the latter influence the processes of socialization and learning at school. The study involved 15 (n = 15) special education teachers (M _age = 40.4; SD = 9.3) from primary schools in Italy who were or had previously been in charge of a pupil with DS. The teachers were interviewed through a semi-structured interview, built ad hoc. The data were analyzed through the grounded theory method supported by ATLAS.ti software. Data analysis produced 20 (n = 20) categories grouped into 6 (n = 6) macro-categories: (1) psychophysical characteristics; (2) learnings; (3) relational aspects; (4) collaborations; (5) extracurricular activities; and (6) teacher training. The research shows that students with DS have good relationships with their peers; however, there are still some important critical issues, including poor training of teachers on certain topics and on the application of collaborative and relationship support strategies, the limited collaboration between support teachers and curricular teachers, and the absence of support from ad hoc professional figures.

Evaluating Processing Speed and Reaction Time Outcome Measures in Children and Adolescents with Down Syndrome

Reliable and valid cognitive outcome measures, including examiner-administered and computer-facilitated assessments of processing speed and reaction time, are necessary for future clinical trials that include individuals with Down syndrome (DS). The current study evaluated the score distributions and psychometric properties of four examiner-administered and three computerized processing speed and reaction time measures. Participants included 97 individuals with DS, aged 6 to 17 (M = 12.6, SD = 3.3). Two examiner-administered measures (Differential Ability Scales-II Rapid Naming and Cat/dog Stroop Congruent) met most predetermined psychometric criteria. Other assessments demonstrated good test-retest reliability and had negligible practice effects but lacked adequate feasibility. Recommendations for using processing speed and reaction time assessments in research and suggestions for modifications of measures are discussed.

Perspectives on adaptive functioning and intellectual functioning measures for intellectual disabilities behavioral research

Introduction

Intellectual disability (ID) is a significant limitation in both intellectual ability and adaptive functioning, but many studies of participants with ID only include a measure of overall intellectual functioning when describing their samples. The purpose of this perspective article was to provide a starting point for future research regarding the utility of including measures of both intellectual and adaptive functioning in research focused on ID. In this article, we discuss the differences and similarities between the constructs of intellectual and adaptive functioning, how they are measured, and the benefits of using both measures to describe participant abilities. Data are presented to demonstrate that intellectual and adaptive functioning measures capture separate but related skills in a sample of individuals with ID (i.e., children with Down syndrome [DS]; the leading genetic cause of ID).

Methods

Thirty children with DS (7–31 months) were administered the Mullen Scales of Early Learning and their mothers were interviewed using the Vineland Adaptive Behavior Scales.

Results

At the group level, Vineland and Mullen composite scores were relatively normally distributed and positively correlated. At the individual level, a concordance correlation coefficient indicated moderate agreement between Vineland and Mullen composite scores.

Discussion

Although many children showed consistency between measures, others did not. Our discussion and findings, though preliminary, highlight that intellectual and adaptive functioning are separate but related skills and that there are benefits to including both measures when describing samples with ID. We discuss considerations for including adaptive functioning measures to enhance future research on individuals with ID.

The effect of manual movements on stuttering in individuals with down syndrome

PURPOSE

Stuttering may disrupt the speech of individuals with Down syndrome (DS), but standard stuttering therapies may be less adapted to these clients' needs. This study examined if their strength in gesture use can lead to the development of a new stuttering therapy.

METHOD

Eighteen individuals with DS who stutter participated in an experimental task. During this task, they produced sentences in three different conditions: once without the ability to use gestures, once while moving the mouth of a hand puppet synchronous with their speech, and once while making beat gestures along their speech. Stuttering frequency was measured and compared between conditions while controlling for the effect of articulation rate.

RESULTS

The experimental hand puppet and beat condition did not affect the stuttering frequency, but the covariate articulation rate did. An exploratory posthoc analysis showed that the articulation rate decreased during the experimental hand puppet and beat condition. Manual movements in the present task might only induce fluency through articulation rate reduction. However, analyses at individual level show significant interindividual variability.

CONCLUSION

Individual analyses show that effect on stuttering frequency cannot be attributed entirely to articulation rate reduction and that beat gestures might still play a role. However, at this point, there is not enough direct evidence to implement beat gestures in current stuttering therapy.

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.

Acquisition of cognitive and communication milestones in infants with Down syndrome

BACKGROUND

Understanding the timing of developmental milestones in typical and clinical populations facilitates intervention planning and the early detection of risk for co-occurring conditions. Normative timing of developmental milestone achievement has been established for typically developing children. However, there is little information regarding the timing of cognitive and communication skill acquisition in young children with Down syndrome (DS). The objectives of this study are to (1) provide foundational information regarding the timing of cognitive and communication skill acquisition in infants with DS and (2) facilitate the early identification of infants with risk for co-occurring conditions.

METHOD

Seventy-four infants with DS (age range: 4-18 months) completed the Bayley Scales of Infant Development-III (Bayley 2006). Individual items from the cognitive and communication scales were selected for analysis. Parents provided information regarding their infant's developmental and family history.

RESULTS

The percentage of infants who attained each skill was calculated within 2-month age bands. For infants who did not show skill acquisition within each age band, the rates of prematurity, heart defects, corrective heart surgery and significant illness were calculated as well.

CONCLUSIONS

This study provides foundational information that can contribute to the formulation of a developmental schedule for cognitive and language milestone acquisition in infants with DS.

Down syndrome patients with normal hearts: are they really normal?

Even though congenital heart disease is a common finding in down syndrome (DS) patients, some of them have anatomically normal hearts. However, the term "normal" might not be suitable, as these patients usually suffer from functional cardiac dysfunction. Several research highlighted that despite the absence of anatomical heart defects, subtle cardiac function derangements are present in DS patients. We aim to assess cardiac functions by Two-dimensional echocardiography and tissue Doppler imaging (TDI) in pediatric DS patients who have anatomically normal hearts. One hundred seventy-two patients with karyotyping confirmed DS with anatomically normal hearts and 165 healthy normal control children were enrolled in the current study. Their cardiac functions were assessed using both 2-dimensional echocardiography and TDI. Both patients and controls had structurally and anatomically normal hearts. In DS patients, the right side of the heart showed a significant reduction in both systolic and diastolic functions. Systolic dysfunction was evident by significantly decreased levels of Tricuspid annular plane systolic excursion and systolic wave by TDI. Diastolic dysfunction of the right ventricle was evident by prolonged deceleration time by conventional echocardiography and a significant decrease in annular tissue doppler velocity during early diastole/late diastole ratio by TDI. The E/De ratio was significantly increased. Even with anatomically normal hearts, DS patients should undergo cardiac function assessment by echocardiography & TDI. TDI is superior to conventional echocardiography in detecting subtle cardiac dysfunction especially left ventricular diastolic dysfunction in DS patients. TDI showed a significant decrease in the early/atrial ratio of mitral valve annulus and prolongation of left ventricle isometric relaxation time in DS children. Also, the left ventricle E/De ratio was prolonged denoting elevated filling pressures and diastolic dysfunction. This indicates that the TDI has higher sensitivity to detect diastolic dysfunction than conventional Echocardiography. Biventricular TDI-derived myocardial performance index was found to be significantly increased in DS children.

Intranasal Administration of KYCCSRK Peptide Rescues Brain Insulin Signaling Activation and Reduces Alzheimer's Disease-like Neuropathology in a Mouse Model for Down Syndrome

Down syndrome (DS) is the most frequent genetic cause of intellectual disability and is strongly associated with Alzheimer's disease (AD). Brain insulin resistance greatly contributes to AD development in the general population and previous studies from our group showed an early accumulation of insulin resistance markers in DS brain, already in childhood, and even before AD onset. Here we tested the effects promoted in Ts2Cje mice by the intranasal administration of the KYCCSRK peptide known to foster insulin signaling activation by directly interacting and activating the insulin receptor (IR) and the AKT protein. Therefore, the KYCCSRK peptide might represent a promising molecule to overcome insulin resistance. Our results show that KYCCSRK rescued insulin signaling activation, increased mitochondrial complexes levels (OXPHOS) and reduced oxidative stress levels in the brain of Ts2Cje mice. Moreover, we uncovered novel characteristics of the KYCCSRK peptide, including its efficacy in reducing DYRK1A (triplicated in DS) and BACE1 protein levels, which resulted in reduced AD-like neuropathology in Ts2Cje mice. Finally, the peptide elicited neuroprotective effects by ameliorating synaptic plasticity mechanisms that are altered in DS due to the imbalance between inhibitory vs. excitatory currents. Overall, our results represent a step forward in searching for new molecules useful to reduce intellectual disability and counteract AD development in DS.

Number estimation in Down syndrome: Cognition or experience?

BACKGROUND

The ability to place numbers on a visual "number line" is a hallmark of the understanding of numerical magnitude and it is a strong predictor of mathematical achievement.

AIM

We examined whether the performance in the number line estimation task is more driven by mental age or experience with numbers in a sample of Italian children with Down syndrome (DS).

METHOD AND PROCEDURE

Sixty-three children with DS (M_months = 128.62, SD = 30.73) and sixty-three typically developing children (M_months = 54.98, SD = 6.34) matched one to one for mental age completed number line estimation tasks and other tests to assess their numerical knowledge.

OUTCOMES AND RESULTS

No significant differences emerged between the two groups in terms of accuracy of positioning numbers on the 1-10 and 1-20 interval. In addition, the accuracy on the 1-10 interval was related to the ability to recognize numbers, while the accuracy on the 1-20 line was related to the ability to compare magnitudes.

CONCLUSION AND IMPLICATION

Results suggest that in individuals with DS the linear mapping of numbers is driven by mental age, but the accuracy of positioning numbers is also shaped by the experience with symbolic numbers. Therefore, the improvement of numerical estimation abilities should be a target of intervention programs.

Oral health status in individuals with Down syndrome

Down syndrome (DS) is a neurodevelopmental disorder of known genetic cause, with a wide array of oral and systemic manifestations. The aim of the present study is to determine the level of oral hygiene status and practice of a group of individuals with DS in Benghazi/Libya. In this cross–sectional study 124 individuals were recruited from The Rehabilitation Centre of Special Needs in the city of Benghazi, Libya. Questionnaires were distributed among the attendees, covering oral health aspects and diet habits. Oral examination was conducted to evaluate oral health status among individuals with DS. The data were analysed descriptively and inferentially (including Chi-square test and Fisher’s exact test) using the Statistical Package for Social Science version 20 (SPSS). Most of DS individuals brush their teeth once daily (62%), spending less than one minute in brushing (44%). For diet habits, more than half (55%) eat sweet snacks between meals. For the dental status, 47% of the subject had zero DMFT, followed by score 2 in 21%. The highest percentage in Oral hygiene Index (OHI) was scored 1 by 46% of participants. The zero CPITN score was seen in 54.5%. Our results have shown a weaker tendency of DS towards oral hygiene. This should strengthen our goal of guiding and encouraging parents of individuals with DS to be more cautious in providing help and supervision of their individuals’ practice of oral health care.

The association between expressive language skills and adaptive behavior in individuals with Down syndrome

The primary goal of this study was to determine whether expressive language skills contribute to adaptive behavior (e.g., socialization and daily living skills) in children, adolescents, and young adults with Down syndrome (DS) whilst controlling for age and nonverbal cognitive ability. Expressive language was assessed using the psychometrically validated Expressive Language Sampling (ELS) conversation and narration procedures. The language produced was transcribed and analyzed to yield measures of expressive vocabulary, syntax, and intelligibility. Socialization and daily living skills of participants with DS were measured with the Vineland Adaptive Behavior Scales, 2nd edition (VABS-2) parent/caregiver rating form. Our results show that the three ELS measures were significantly correlated with multiple measures from the VABS-2 when controlling for age. Several correlations remained significant even when nonverbal cognitive ability was included as a control variable. Our results suggest that expressive language skills contribute to adaptive behavior in children, adolescents, and young adults with DS regardless of age and some of these associations are not explained solely by overall cognitive delays. Further studies including longitudinal data are needed to extend our results.

Parents' Experiences of Having a Child with Down Syndrome and Sleep Difficulties

OBJECTIVES

Sleep disorders are prevalent in children with Down Syndrome (DS). However, sleep treatment is not always readily accessed by this group. This study aims to understand families' experiences of having a child with DS and sleep difficulties, and in particular, their healthcare experiences, with the goal of informing practice improvements.

METHODS

We conducted semi-structured interviews with 34 parents (fathers n = 4 and mothers n = 30) with open-ended questions about parents' experiences of sleep, family dynamics, and healthcare. We operationalized a reflexive Thematic Analysis.

RESULTS

Parents normalized their experiences of having a child with DS and sleep problems. Parents acknowledged that sleep disruption has adverse and pervasive impacts on their wellbeing and family dynamics, but also found this difficult to identify as a health problem. They accepted sleep difficulties as a regular part of bringing up any child, particularly one with a disability. When they did seek treatment for their child's sleep difficulties, parents often reported encountering insensitive and inadequate care and described that, at times, healthcare professionals also normalized children's sleep difficulties, resulting in sub-optimal treatment. This included at times failure to refer to tertiary sleep medicine services when required.

CONCLUSIONS

Parents' and healthcare professionals' normalization of sleeping difficulties denies that they are both deleterious and modifiable. Practice implications include raising healthcare professionals' awareness of the importance of proactively addressing sleep, with sensitivity to families' normalization strategies, recognizing that families may require prompting to report concerns.

Profiles of Caregiver-Reported Executive Function in Children with Down Syndrome

Children with Down syndrome (DS) are at risk for challenges with aspects of executive function (EF). The current study explores whether heterogeneity in EF profiles can be detected within a sample of children with DS. Participants were 69 children with DS, ages 3-10 years (M = 6.23, SD = 1.91). T-scores from a caregiver-report measure of executive function were modeled using latent profile analysis, and auxiliary analyses examined the association between demographic and biomedical factors and probability of profile membership. The two-profile solution was the best fit for the sample, with a profile that involved elevated scores in working memory only ("Working Memory Only" profile; 43% of sample) and a "Multi-Domain" profile that involved elevated scores in planning, inhibition, and working memory (57%). The presence of congenital heart defects was associated with a higher probability of assignment to the Multi-Domain profile. Findings from this study contribute to the characterization of heterogeneous outcomes associated with DS.

Assessment of the Correlation between the Levels of Physical Activity and Technology Usage among Children with Down Syndrome in the Riyadh Region

Background: Children with Down Syndrome (C-DS) have language, cognitive and communication difficulties, in addition to consistent physical inactivity that contributes to poor health and higher-disability-adjusted life years. The purpose of this study was to determine the correlation between the use of electronic technology and levels of physical activity in C-DS in the Riyadh region of Saudi Arabia. Methods: A cross-sectional study was conducted with 49 mothers, where each had a child (6-12 years of age) with Down Syndrome (DS), and who were recruited using purposive sampling from three DS centers in Riyadh, Saudi Arabia. The Children's Physical Activity Questionnaire and Research Questionnaire on the Impact of Technology on Children were used. Descriptive statistics were used to describe the demographics. Pearson's correlation, Student's t-test and the Chi-square test were used to assess the association between technology use, physical activity levels and socio-demographic variables. Results: There was no significant correlation between physical activity and the use of technology by C-DS. However, there was a negative correlation between a high level of physical activity and technology use (R = -0.037). Although, no significant correlation between the mother's characteristics and technology use was found; there was a significantly positive correlation (p = 0.05) between the education level of mothers and the technology use by C-DS. Nonetheless, there was no association between the physical activity level and the gender of the child with DS. Conclusions: This study found that no significant relationship exists between the use of electronic gadgets and the level of physical activity in C-DS.

Considerations for measuring individual outcomes across contexts in Down syndrome: Implications for research and clinical trials

Individuals with Down syndrome (DS) are increasingly involved in clinical trials that target developmental outcomes, like cognition and behavior. The increased focus on treatment in DS has led to ongoing discussions regarding the selection of outcome measures using syndrome-informed criteria. This discourse is warranted as clinical trials can fail if the outcome measures selected are inappropriate for individuals with DS or do not take into account the behavioral phenotype commonly associated with DS. This review focuses on the challenges present in the measurement of outcomes in DS, with a specific focus on considerations made in evaluating cognitive, language, and behavioral/psychopathology outcomes. This review also provides a summary of recommendations for assessment of outcomes in these domains as well as recommendations for future research. The impact of physical health and assessment psychometrics on the measurement of outcomes is also reviewed.

Structural Connectivity in Down Syndrome and Alzheimer's Disease

Down syndrome (DS) arises from the triplication of chromosome 21, which leads to an atypical neurodevelopment and the overproduction of the amyloid precursor protein, predisposing to early Alzheimer's disease (AD). Not surprisingly, trisomy 21 is widely considered a model to study predementia stages of AD. After decades, in which neural loss was the main focus, research in AD is now moving toward understanding the neurodegenerative aspects affecting white matter. Motivated by the development of magnetic resonance imaging (MRI)-based diffusion techniques, this shift in focus has led to several exploratory studies on both young and older individuals with DS. In this review, we synthesise the initial efforts made by researchers in characterising in-vivo structural connectivity in DS, together with the AD footprint on top of such pre-existing connectivity related to atypical brain development. The white matter structures found to be affected in DS are the corpus callosum and all the main long-association fibres, namely the inferior fronto-occipital fasciculus, the inferior and superior longitudinal fasciculus, the uncinate fasciculus and the cingulum bundle. Furthermore, the cingulum bundle and the corpus callosum appear to be particularly sensitive to early AD changes in this population. Findings are discussed in terms of their functional significance, alongside methodological considerations and implications for future research.

Cognitive outcome measures for tracking Alzheimer's disease in Down syndrome

Down syndrome (DS) is now viewed as a genetic type of Alzheimer's disease (AD), given the near-universal presence of AD pathology in middle adulthood and the elevated risk for developing clinical AD in DS. As the field of DS prepares for AD clinical intervention trials, there is a strong need to identify cognitive measures that are specific and sensitive to the transition from being cognitively stable to the prodromal (e.g., Mild Cognitive Impairment-Down syndrome) and clinical AD (e.g., Dementia) stages of the disease in DS. It is also important to determine cognitive measures that map onto biomarkers of early AD pathology during the transition from the preclinical to the prodromal stage of the disease, as this transition period is likely to be targeted and tracked in AD clinical trials. The present chapter discusses the current state of research on cognitive measures that could be used to screen/select study participants and as potential outcome measures in future AD clinical trials with adults with DS. In this chapter, we also identify key challenges that need to be overcome and questions that need to be addressed by the DS field as it prepares for AD clinical trials in the coming years.

Beyond amyloid: Immune, cerebrovascular, and metabolic contributions to Alzheimer disease in people with Down syndrome

People with Down syndrome (DS) have increased risk of Alzheimer disease (AD), presumably conferred through genetic predispositions arising from trisomy 21. These predispositions necessarily include triplication of the amyloid precursor protein (APP), but also other Ch21 genes that confer risk directly or through interactions with genes on other chromosomes. We discuss evidence that multiple genes on chromosome 21 are associated with metabolic dysfunction in DS. The resulting dysregulated pathways involve the immune system, leading to chronic inflammation; the cerebrovascular system, leading to disruption of the blood brain barrier (BBB); and cellular energy metabolism, promoting increased oxidative stress. In combination, these disruptions may produce a precarious biological milieu that, in the presence of accumulating amyloid, drives the pathophysiological cascade of AD in people with DS. Critically, mechanistic drivers of this dysfunction may be targetable in future clinical trials of pharmaceutical and/or lifestyle interventions.

Emotional Lexicon in Down Syndrome

We studied comprehension of emotion versus concrete/abstract words in Down syndrome (DS). Study 1 compared 26 participants with DS and 26 typically developing (TD) children matched on verbal ability. Results showed no difference between groups. Study 2 assessed whether chronological age (CA) and (non)verbal abilities predicted developmental trajectories of comprehension in 36 children with DS and 143 TD children. For the latter, these variables predicted comprehension of all three word types. For the former, receptive vocabulary predicted comprehension of all word types, but CA and nonverbal reasoning only predicted comprehension of concrete words. This suggests that people with DS have no specific emotional lexicon deficit. Supporting their general lexical development would help them access abstract and emotional meanings.

Defining Expressive Language Benchmarks for Children with Down Syndrome

Establishing expressive language benchmarks (ELBs) for children with Down syndrome (DS), as developed by Tager-Flusberg et al. for children with autism, is critically needed to inform the development of novel treatments, identify individualized treatment targets, and promote accurate monitoring of progress. In the present study, we assessed ELB assignments in three language domains (phonology, vocabulary, and grammar) for 53 young children with DS (CA range: 2.50–7.99 years) using standardized assessments. The participants were classified into one of four ELB levels (preverbal, first words, word combinations, and sentences) in each language domain. Associations with additional measures of language, chronological age, nonverbal cognition, and verbal short-term memory were considered. Analyses of individual ELB profiles indicated substantial variability across the three language domains, with six different patterns of variation across domains emerging. At the same time, the ELB categories were significantly associated with independent language measures and broader developmental domains. Moreover, ELB changes were observed in a small sample of children with DS reassessed 18–24 months after the initial visit. Results from the present study suggest the procedures outlined by Tager-Flusberg et al. for defining ELBs are a potentially useful tool for describing the language abilities of children with DS.

Language Intervention in Down Syndrome: A Systematic Literature Review

Language is one of the most affected areas in people with Down syndrome and is one of the most influential throughout their development. That is why the linguistic difficulties presented by this group are susceptible to treatment through different specific interventions. However, little emphasis has been placed on the effectiveness and importance of this type of intervention in improving their language skills. Therefore, this work aimed to carry out a systemic literature review of language intervention programs that have been carried out in the last 20 years. To this end, a total of 18 articles were analyzed in which the effectiveness of different types of treatment related to oral language, written language and communication, in general, was studied, using the guidelines of the PRISMA Statement and the COSMIN methodology. The results highlight that language intervention improves linguistic levels in people with Down Syndrome. Most of the research focuses on early interventions and interventions carried out through individual sessions. Nevertheless, the data are unanimous in considering the efficacy and effectiveness of the proposed treatments for improving the language skills of people with Down syndrome. Thus, linguistic intervention is a fundamental area of work throughout the lives of people with Down syndrome.

Relationship between growth and intelligence quotient in children with Down syndrome

BACKGROUND

The relationship between intelligence quotient (IQ) and somatic development, especially growth, has been demonstrated in various groups of children. Down syndrome (DS) is characterized by short stature, overweight, and cognitive impairment. The objective of our work was to assess whether anthropometric measurements [weight, height, body mass index (BMI)] of children with DS correlate with their IQ. The results of the study may be valuable for this population in the light of increasing access to growth hormone therapy (GHT) in various genetic syndromes with short stature. Based on previous studies on children, we hypothesized that a link exists between IQ and somatic development, particularly growth.

METHODS

This cross-sectional study included 40 children with DS, who were aged 9-18 years. The studied population was selected from the registry of the Genetic Clinic at the University Clinical Center in Gdańsk (Poland). Anthropometric measurements (weight and height) were taken for all the children, and their BMI was determined using these data. The obtained results were plotted on charts for children with DS. The IQ of the children was assessed using the Stanford Binet Intelligence Scale, Fifth Edition. The correlations between IQ and anthropometric data were analyzed using univariate correlation and multiple regression analyses.

RESULTS

The results showed that full-scale, verbal, and nonverbal IQ correlated with height percentile (P=0.03, P=0.02, and P=0.04, respectively), but not with weight (P=0.26, P=0.19, and P=0.61, respectively) or BMI (P=0.6, P=0.5, and P=0.72, respectively). In multiple linear regression analysis, height percentile remained as an independent determinant of the IQ results after adjusting for birth weight, hypothyroidism with L-thyroxine replacement therapy, and congenital cardiac defect (β=0.48, P=0.018).

CONCLUSIONS

The results of our study suggest an association between growth and IQ in children with DS. The presented findings may be valuable for improving access to GHT for populations with genetic syndromes characterized by short stature. However, these should be confirmed by further research with a longitudinal sample of children with DS.

Conducting clinical trials in persons with Down syndrome: summary from the NIH INCLUDE Down syndrome clinical trials readiness working group

The recent National Institute of Health (NIH) INCLUDE (INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE) initiative has bolstered capacity for the current increase in clinical trials involving individuals with Down syndrome (DS). This new NIH funding mechanism offers new opportunities to expand and develop novel approaches in engaging and effectively enrolling a broader representation of clinical trials participants addressing current medical issues faced by individuals with DS. To address this opportunity, the NIH assembled leading clinicians, scientists, and representatives of advocacy groups to review existing methods and to identify those areas where new approaches are needed to engage and prepare DS populations for participation in clinical trial research. This paper summarizes the results of the Clinical Trial Readiness Working Group that was part of the INCLUDE Project Workshop: Planning a Virtual Down Syndrome Cohort Across the Lifespan Workshop held virtually September 23 and 24, 2019.

Cell models for Down syndrome-Alzheimer’s disease research

Down syndrome (DS) is the most common chromosomal abnormality and leads to intellectual disability, increased risk of cardiac defects, and an altered immune response. Individuals with DS have an extra full or partial copy of chromosome 21 (trisomy 21) and are more likely to develop early-onset Alzheimer’s disease (AD) than the general population. Changes in expression of human chromosome 21 (Hsa21)-encoded genes, such as amyloid precursor protein (APP), play an important role in the pathogenesis of AD in DS (DS-AD). However, the mechanisms of DS-AD remain poorly understood. To date, several mouse models with an extra copy of genes syntenic to Hsa21 have been developed to characterise DS-AD-related phenotypes. Nonetheless, due to genetic and physiological differences between mouse and human, mouse models cannot faithfully recapitulate all features of DS-AD. Cells differentiated from human-induced pluripotent stem cells (iPSCs), isolated from individuals with genetic diseases, can be used to model disease-related cellular and molecular pathologies, including DS. In this review, we will discuss the limitations of mouse models of DS and how these can be addressed using recent advancements in modelling DS using human iPSCs and iPSC-mouse chimeras, and potential applications of iPSCs in preclinical studies for DS-AD.

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.

Cognitive profiles in children and adolescents with Down syndrome

The Down syndrome (DS) phenotype is usually characterized by relative strengths in non-verbal skills and deficits in verbal processing, but high interindividual variability has been registered in the syndrome. The goal of this study was to explore the cognitive profile, considering verbal and non-verbal intelligence, of children and adolescents with DS, also taking into account interindividual variability. We particularly aimed to investigate whether this variability means that we should envisage more than one cognitive profile in this population. The correlation between cognitive profile and medical conditions, parents’ education levels and developmental milestones was also explored. Seventy-two children/adolescents with DS, aged 7–16 years, were assessed with the Wechsler Preschool and Primary Scale of Intelligence-III. Age-equivalent scores were adopted, and Verbal and Non-Verbal indices were obtained for each individual. The cognitive profile of the group as a whole was characterized by similar scores in the verbal and non-verbal domain. Cluster analysis revealed three different profiles, however: one group, with the lowest scores, had the typical profile associated with DS (with higher non-verbal than verbal intelligence); one, with intermediate scores, had greater verbal than non-verbal intelligence; and one, with the highest scores, fared equally well in the verbal and non-verbal domain. Three cognitive profiles emerged, suggesting that educational support for children and adolescents with DS may need to be more specific.

Influence of gestures on the intelligibility and comprehensibility of utterances with stuttering events in individuals with Down syndrome

INTRODUCTION

Individuals with Down syndrome (DS) often stutter, which can affect their speech intelligibility. Previous research has shown that manual signs can enhance speech intelligibility and comprehensibility. It remains unclear to what extent spontaneous hand gestures, such as iconic and beat gestures, may enhance intelligibility and/or comprehensibility during utterances with stuttering events.

METHODS

Eleven individuals with DS who stutter provided video-recorded speech samples. From these samples, 60 utterances containing a stuttering event were selected. In half of them, the stuttering events were accompanied by gestures; in the other half, the stuttering events were not accompanied by gestures. The samples were shown to 250 assessors who were blind to the study's goals. Each sample was shown in three visibility conditions: 1) video-with-audio, 2) video-with-audio but with the speaker's mouth covered and 3) audio-only. The assessors rated speech intelligibility on a 7-point Likert scale and transcribed the speech sample. The effect of gesture production, gesture type and the visibility conditions on comprehensibility and intelligibility was examined with a hierarchical multiple linear regression.

RESULTS

When a speaker had used a gesture during a stuttering event, the Likert scale score increased with 0.47 and the accuracy of transcription with 9.07%. There was no difference in effect between the different gesture types. Despite the effect from gesture use, there was no effect of the visibility conditions on the Likert scale or transcription score.

CONCLUSIONS

Gestures positively affect intelligibility and comprehensibility of utterances with stuttering events in individuals with DS by altering the speech production. The possibility of beat gestures as a therapy method should be examined, with caution for the development of maladaptive behaviours.

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.

Classification of Factors Effect on Sleep in Individuals with Down Syndrome

BACKGROUND

Sleep disordered breathing (SDB) is a frequent disorder with serious adverse health consequences in people with Down syndrome (DS). This study aims to evaluate and classify sleep and physical activity (PA) characteristics in adults with DS.

METHODS

Forty participants with DS wore an accelerometer for seven consecutive days to measure physical activity and sleep-wake patterns. The corresponding data were also obtained by survey and polysomnography. The apnea-hypopnea index (AHI) is calculated from the number of apneas and hypopneas per hour of sleep according to international guidelines.

RESULTS

Polysomnography showed SDB based on AHI in 95% of adults: 50% had severe SDB, 22.5% presented moderate and 22.5% mild SDB, predominantly in males. They had poor sleep quality (80.1%) and low PA levels. Using statistical classification methods, we observed three clusters with two opposite profiles. Clusters 2 and 3 showed low PA indices (daily steps: 5719 and 5310, respectively) and severe SDB (AHI = 33.6 and 55.5 events/h), high age and high gonial angle. Cluster 1 showed high PA (mean count of daily steps: 6908) and mild to moderate SDB (AHI = 16.8 events/h), low age and low gonial angle.

CONCLUSIONS

Our findings suggest that there are different profiles (age, gender, obesity, gonial angle) that are associated with SDB in adults with DS. These results suggest that this may represent important factors to consider when planning health promotion and prevention.

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.

Symptoms of Autism, Comorbid Mental Health Conditions and Challenging Behaviors among Toddlers with Down Syndrome at Low Risk for ASD-Characterization Using the BISCUIT-Parts 1-3

Background: Autism spectrum disorder (ASD) may coexist with Down syndrome (DS). Most studies on this topic involve school-age children, adolescents, or adults with DS. This study looked at ASD symptoms, other mental health problems, and challenging behaviors in toddlers with DS at low risk of ASD. Methods: We used screening tools for autism in toddlers; BISCUIT–Parts 1–3 and Q-CHAT. We compared four groups of children aged 17–37 months: DS, ASD, Atypical Development (AD), and Typically Developing (TD). Results: Children with DS showed lower symptoms of ASD than children with ASD (without DS) and higher than TD children, except for repetitive behaviors/restricted interests. For comorbid mental health problems and difficult behaviors, children with DS scored lower than children with ASD. There were no differences between children with DS and TD children in this regard. Conclusions: The study results indicate that BISCUIT–Parts 1–3 are valid instruments to differentiate toddlers with DS from toddlers with ASD. However, they also show that toddlers with DS at low ASD risk are a very heterogeneous group when the ASD symptoms are considered. Autistic characteristics should be taken into account in supporting young children with this genetic condition.

Sleep, Function, Behaviour and Cognition in a Cohort of Children with Down Syndrome

Objective: To describe the sleep problems experienced by children with Down syndrome attending a tertiary sleep clinic and relationship with behaviour, function and cognition. Methods: Data were collected from children with Down syndrome aged 3–18 years old. Carers completed the Abbreviated Child Sleep Habits Questionnaire, Child Behaviour Checklist and Life-Habits Questionnaire at enrolment. Cognitive assessment (Stanford-Binet 5) was undertaken by a trained psychologist. Children received management for their sleep problem as clinically indicated. Results: Forty-two subjects with a median age of 6.8 years (Interquartile Range-IQR 4.5, 9.8) were enrolled. A total of 92% were referred with snoring or symptoms of Obstructive Sleep Apnoea (OSA), with 79% of those referred having had previous ENT surgery. Thus, 85% of all participants underwent a sleep study and 61% were diagnosed with OSA (OAHI ≥ 1/h). Based on questionnaires, 86% of respondents indicated that their child had a significant sleep disorder and non-respiratory sleep problems were common. Non-respiratory problems included: trouble going to sleep independently (45%), restless sleep (76%), night-time waking (24%) and bedtime resistance (22%). No significant correlations were found between sleep measures (behavioural and medical sleep problems) and the behavioural, functional or cognitive parameters. Conclusion: Sleep disorders were very common, especially non-respiratory sleep problems. OSA was common despite previous surgery. No association was found between sleep-related problems (snoring, sleep-study-confirmed OSA or non-respiratory sleep problem) and parent-reported behavioural problems, functional impairments or intellectual performance. This may reflect limitations of the measures used in this study, that in this population ongoing problems with daytime function are not sleep related or that a cross-sectional assessment does not adequately take into account the impacts of past disease/treatments. Further research is required to further evaluate the tools used to evaluate sleep disorders, the impact of those disorder on children with Down syndrome and interventions which improve both sleep and daytime function.

Oral Health Status of Down's Syndrome Patients in Aseer, Saudi Arabia

Introduction:

It was observed that compared to the general population, mentally challenged subjects have higher rates of poor oral hygiene. Gingivitis is a common finding with moderate or severe variety reported most commonly. Periodontal disease is the most significant oral health problem, which can even lead to mobility of tooth and tooth loss. It is essential to generate oral health precautionary agendas and familiarize it with them.

Materials and Methods:

Four Centres of rehabilitation in the Aseer region of Saudi Arabia were included and subjects of 3–24 year age group was examined. Written informed consent was obtained from directors of Centres. Caries, oral hygiene status, soft-tissue and hard-tissue lesions were evaluated and statistically analyzed.

Results:

Higher Decayed, Missing and Filled Teeth score was observed in the present study in contrast to many other studies. Periodontal disease was seen in higher age group with higher percentages. Poor oral hygiene was seen in 27.3% of males and 66.7% of females. Tongue lesions comprised 85.7%, which accounted for the major part of soft-tissue abnormality. Various occlusal abnormalities (75%) and developmental tooth disturbances (53.6%) constitute the higher portion in hard-tissue abnormality.

Conclusion:

Dentists should be conscious of the range of oral anomalies that can manifest in this group of the patients. The microbial or serological investigation was not done which could have explained the etiology behind these lesions. In spite of these confines, the survey result have provided information regarding the oral health status of Down's syndrome subjects and the necessity of focusing on oral health need.

Relationship between Apgar scores and long-term cognitive outcomes in individuals with Down syndrome

This study examined the contribution of the Apgar score at 1 and 5 min after birth to later cognitive functioning in 168 individuals with Down syndrome who were between 6 and 25 years of age at time of cognitive testing. Our results showed that a lower Apgar score at 1 min was related to a worse performance in later cognitive measures of receptive vocabulary, verbal comprehension and production, visual memory and working memory. Results also showed that a lower Apgar score at 5 min was only related to worse later outcomes of verbal comprehension and production and auditory working memory. Our findings suggest a need for future studies investigating how specific perinatal events reflected in the Apgar score are linked to later cognitive functioning in individuals with Down syndrome.