Adaptive behavior in infants and toddlers with Down syndrome and fragile X syndrome

Development, education, and services in children with Down syndrome: a cohort analysis from a clinical database

Background

Prior research has characterized neurodevelopmental phenotypes for Down syndrome (DS), but there is variability in age of milestone attainment and limited identification of early predictors of developmental trajectories. Additionally, less is known about receipt of education and services in relation to development.

Objective

This study describes the delivery of education and therapies in the setting of general developmental and behavioral needs in a large clinical cohort of children with DS seen in a specialized Down Syndrome Program (DSP).

Method

The clinically collected data included 814 patients with DS who were seen at a specialty DSP at a large, tertiary pediatric care center from March 2018 to January 2023. Data were collected through caregiver-and clinician-reported history at clinical visits to the program. Descriptive frequencies were utilized to describe participant demographics, skills and behaviors, and receipt of services, across age groups in childhood.

Results

Delays were present across all developmental domains; in particular delays in language, communication, and academic skills, and behavioral challenges were commonly reported. Almost all children received Early Intervention (EI) services, and many young children received non-public therapies after completing EI. Older participants demonstrated more impairments than younger age groups, yet received services at lower rates, particularly behavioral and speech language interventions.

Conclusion

A snapshot of developmental skill attainment in individuals with DS is provided. Therapies to support the levels of need were reported at much lower frequencies than the level of need reported to target aspects of development and behavior. Several gaps in therapies and educational services were identified. There is an important need for tailoring supports, based on developmental level, to meet individual needs. These findings may help to inform policy change related to developmental and educational services for individuals with DS.

X- vs. Y-chromosome influences on human behavior: a deep phenotypic comparison of psychopathology in XXY and XYY syndromes

BACKGROUND

Do different genetic disorders impart different psychiatric risk profiles? This question has major implications for biological and translational aspects of psychiatry, but has been difficult to tackle given limited access to shared batteries of fine-grained clinical data across genetic disorders.

METHODS

Using a new suite of generalizable analytic approaches, we examine gold-standard diagnostic ratings, scores on 66 dimensional measures of psychopathology, and measures of cognition and functioning in two different sex chromosome aneuploidies (SCAs)-Klinefelter (XXY/KS) and XYY syndrome (n = 102 and 64 vs. n = 74 and 60 matched XY controls, total n = 300). We focus on SCAs for their high collective prevalence, informativeness regarding differential X- vs. Y-chromosome effects, and potential relevance for normative sex differences.

RESULTS

We show that XXY/KS elevates rates for most psychiatric diagnoses as previously reported for XYY, but disproportionately so for anxiety disorders. Fine-mapping across all 66 traits provides a detailed profile of psychopathology in XXY/KS which is strongly correlated with that of XYY (r = .75 across traits) and robust to ascertainment biases, but reveals: (i) a greater penetrance of XYY than KS/XXY for most traits except mood/anxiety problems, and (ii) a disproportionate impact of XYY vs. XXY/KS on social problems. XXY/KS and XYY showed a similar coupling of psychopathology with adaptive function and caregiver strain, but not IQ.

CONCLUSIONS

This work provides new tools for deep-phenotypic comparisons of genetic disorders in psychiatry and uses these to detail unique and shared effects of the X- and Y-chromosome on human behavior.

Strategic Implementation of Fragile X Carrier Screening in China: A Focused Pilot Study

Fragile X syndrome is the leading genetic cause of intellectual disability and autism spectrum disorders. Female premutation carriers exhibit no obvious symptoms during reproductive age, but the premutation allele can expand to full mutation when transmitted to the fetus. Given the relatively low prevalence but large population, the distinct health care system, the middle-income economic status, and low awareness among public and medical professionals, the optimal genetic screening strategy remains unknown. We conducted a pilot study of Fragile X carrier screening in China, involving 22,245 pregnant women and women with childbearing intentions, divided into control and pilot groups. The prevalence of Fragile X carriers in the control group was 1 of 850, similar to East Asian populations. Strikingly, the prevalence of Fragile X carriers in the pilot group was 1 of 356, which can be attributed to extensive medical training, participant education, and rigorous genetic counseling and testing protocols. Cost-effectiveness analyses of four strategies-no screening, population-based screening, targeted screening, and our pilot screening-indicated that our pilot screening was the most cost-effective option. A follow-up survey revealed that 55% of respondents reported undergoing screening because of their family history. We have successfully established a standardized system, addressing the challenges of low prevalence, limited awareness, and genetic testing complexities. Our study provides practical recommendations for implementing Fragile X carrier screening in China.

Developmental associations between motor and communication outcomes in Fragile X syndrome: Variation in the context of co-occurring autism

LAY ABSTRACT

Fragile X syndrome (FXS), the leading heritable cause of intellectual disability, has a co-occurrence rate of autism spectrum disorder (ASD) estimated at ~60%. Children with FXS experience delayed achievement and slower development of key motor abilities, which happens to an even greater extent for children with both FXS and ASD. A multitude of studies have demonstrated that motor abilities are foundational skills related to later communication outcomes in neurotypical development, as well as in the context of ASD. However, these associations remain unexamined in FXS, or FXS + ASD. In this study, we aimed to determine the associations between early motor skills and their rate of development on communication outcomes in FXS. Furthermore, we investigated whether these associations varied in the context of co-occurring FXS + ASD. Results revealed within-FXS variation in the context of co-occurring ASD between some aspects of motor development and communication outcomes, yet within-FXS consistency between others. Findings provide evidence for variability in developmental processes and outcomes in FXS in the context of co-occurring ASD and offer implications for intervention.

Developmental associations between cognition and adaptive behavior in intellectual and developmental disability

BACKGROUND

Intellectual and developmental disabilities (IDDs) are associated with both cognitive challenges and difficulties in conceptual, social, and practical areas of living, commonly referred to as adaptive behavior (DSM-5). Although cross-sectional associations between intelligence or cognition and adaptive behavior have been reported in IDD populations, no study to date has examined whether developmental changes in cognition contribute to or track with changes in adaptive behavior. The present study sought to examine associations of longitudinal developmental change in domains of cognition (NIH Toolbox Cognition Battery, NIHTB-CB) and adaptive behavior domains (Vineland Adaptive Behavior Scales-3; VABS-3) including Socialization, Communication, and Daily Living Skills (DLS) over a two year period in a large sample of children, adolescents and young adults with IDD.

METHODS

Three groups were recruited, including those with fragile X syndrome, Down syndrome, and other/idiopathic intellectual disability. Eligible participants (n = 263) included those who were between 6 and 26 years (mage = 15.52, sd = 5.17) at Visit 1, and who had a diagnosis of, or suspected intellectual disability (ID), including borderline ID, with a mental age of at least 3.0 years. Participants were given cognitive and adaptive behavior assessments at two time points over a two year period (m = 2.45 years, range = 1.27 to 5.56 years). In order to examine the association of developmental change between cognitive and adaptive behavior domains, bivariate latent change score (BLCS) models were fit to compare change in the three cognitive domains measured by the NIHTB-CB (Fluid Cognition, Crystallized Cognition, Total Cognition) and the three adaptive behavior domains measured by the VABS-3 (Communication, DLS, and Socialization).

RESULTS

Over a two year period, change in cognition (both Crystallized and Total Composites) was significantly and positively associated with change in daily living skills. Also, baseline cognition level predicted growth in adaptive behavior, however baseline adaptive behavior did not predict growth in cognition in any model.

CONCLUSIONS

The present study demonstrated that developmental changes in cognition and adaptive behavior are associated in children and young adults with IDD, indicating the potential for cross-domain effects of intervention. Notably, improvements in DLS emerged as a primary area of adaptive behavior that positively related to improvements in cognition. This work provides evidence for the clinical, "real life" meaningfulness of changes in cognition detected by the NIHTB-CB in IDD, and provides empirical support for the NIHTB-CB as a fit-for-purpose performance-based outcome measure for this population.

Developmental Profile in Children Aged 3-6 Years: Down Syndrome vs. Autism Spectrum Disorder

This research aims to compare the developmental profiles of children with autism spectrum disorder (ASD) and children with Down Syndrome (DS) between the ages of 3 and 6 years. The study examines whether these developmental disorders share common developmental milestones or exhibit distinctive characteristics. A total of 43 children, 23 with DS and 20 with ASD, participated in the study. Cognitive and language skills were assessed using standardized tools, including the Battelle Developmental Inventory, Reynell Developmental Language Scales III, and NEPSY-II battery. The results indicated that children with ASD outperformed children with DS in the areas of fine motor skills, gross motor skills, and communication. Additionally, children with ASD demonstrated higher scores in language comprehension and expressive language, compared to children with DS. Significant correlations were found between motor skills and communication abilities. Neuropsychological evaluations revealed significant differences between the two groups in various tasks, such as the comprehension of instructions, body part naming and identification, and recognition of emotions. These findings contribute to our understanding of the similarities and differences between ASD and DS, shedding light on the dissociation between cognition and language and its impact on adaptive functioning in these populations.

Developmental Associations between Cognition and Adaptive Behavior in Intellectual and Developmental Disability

Background

Intellectual and developmental disabilities (IDDs) are associated with both cognitive challenges and difficulties in conceptual, social, and practical areas of living (DSM-5). Individuals with IDD often present with an intellectual disability in addition to a developmental disability such as autism or Down syndrome. Those with IDD may present with deficits in intellectual functioning as well as adaptive functioning that interfere with independence and living skills. The present study sought to examine associations of longitudinal developmental change in domains of cognition (NIH Toolbox Cognition Battery, NIHTB-CB) and adaptive behavior domains (Vineland Adaptive Behavior Scales-3; VABS-3) including Socialization, Communication, and Daily Living Skills (DLS) over a two-year period.

Methods

Eligible participants for this multisite longitudinal study included those who were between 6 and 26 years at Visit 1, and who had a diagnosis of, or suspected intellectual disability (ID), including borderline ID. Three groups were recruited, including those with fragile X syndrome, Down syndrome, and other/idiopathic intellectual disability. In order to examine the association of developmental change between cognitive and adaptive behavior domains, bivariate latent change score (BLCS) models were fit to compare change in the three cognitive domains measured by the NIHTB-CB (Fluid, Crystallized, Composite) and the three adaptive behavior domains measured by the VABS-3 (Communication, DLS, and Socialization).

Results

Over a two-year period, change in cognition (both Crystalized and Composite) was significantly and positively associated with change in daily living skills. Also, baseline cognition level predicted growth in adaptive behavior, however baseline adaptive behavior did not predict growth in cognition in any model.

Conclusions

The present study demonstrated that developmental improvements in cognition and adaptive behavior are associated in children and young adults with IDD, indicating the potential for cross-domain effects of intervention. Notably, improvements in Daily Living Skills on the VABS-3 emerged as a primary area of adaptive behavior that positively related to improvements in cognition. This work provides evidence for the clinical, "real life" meaningfulness of the NIHTB-CB in IDD, and important empirical support for the NIHTB-CB as a fit-for-purpose performance-based outcome measure for this population.

Insomnia Symptoms Are Associated with Measures of Functional Deterioration and Dementia Status in Adults with Down Syndrome at High Risk for Alzheimer's Disease

Background

While obstructive sleep apnea (OSA) and insomnia symptoms in neurotypical populations are associated with Alzheimer's disease (AD), their association with dementia in adults with Down syndrome (DS) remains less clear, even though these symptoms are prevalent and treatable in DS. Understanding their associations with AD-related dementia status, cognitive impairment, and functional deterioration may lead to interventions to slow decline or disease progression in adults with DS.

Objective

To characterize differences in OSA and insomnia symptom expression by dementia status, and to determine which sleep factors support dementia diagnosis.

Methods

Multimodal consensus conference was used to determine dementia status in 52 adults with DS (52.2 ± 6.4 years, 21 women). Cognitive impairment, adaptive behavior skills, and symptoms of OSA and insomnia were quantified using validated assessments for adults with DS and their primary informants.

Results

A sex by dementia status interaction demonstrated that older women with DS and dementia had more severe terminal insomnia but not OSA symptoms relative to older women with DS who were cognitively stable (CS). Greater insomnia symptom severity was associated with greater functional impairments in social and self-care domains adjusting for age, sex, premorbid intellectual impairment, and dementia status.

Conclusions

Insomnia symptoms are more severe in women with DS with dementia than in women with DS and no dementia, and regardless of dementia status or sex, more severe insomnia symptoms are associated with greater impairment in activities of daily living. These findings underscore the potential importance of early insomnia symptom evaluation and treatment in women with DS at risk of developing AD.

Cross-sectional developmental trajectories in the adaptive functioning of children and adolescents with Down syndrome

BACKGROUND

Persons with Down syndrome (DS) reveal adaptive functioning (AF) difficulties. Studies on AF in DS have focused mainly on describing the profile (i.e., strengths in socialization, and weaknesses in communication), while less is known about age-related differences. This study aimed to elucidate how AF changes with age in children and adolescents with DS, taking a cross-sectional developmental trajectory approach. Moreover, the contribution of both chronological age (CA) and mental age (MA) on AF development was explored.

METHOD

This study involved 115 children and adolescents (between 3 and 16 years old) with DS. Parents were interviewed about their children's AF on communication, daily living and socialization skills. Children and adolescents with DS were assessed on their developmental level.

RESULTS

While participants' standard scores on AF decreased linearly over time, their age-equivalent scores increased with linear or segmented patterns, depending on the skill considered. CA and MA were related to daily living skills and socialization to much the same degree, while MA correlated more strongly than CA with communication.

CONCLUSION

This study contributes to the understanding of how AF develops in children and adolescents with DS, showing that CA and MA both contribute to shaping the skills involved.

X- vs. Y-Chromosome Influences on Human Behavior: A Deep Phenotypic Comparison of Psychopathology in XXY and XYY Syndromes

Do different genetic disorders impart different psychiatric risk profiles? This question has major implications for biological and translational aspects of psychiatry, but has been difficult to tackle given limited access to shared batteries of fine-grained clinical data across genetic disorders. Using a new suite of generalizable analytic approaches, we examine gold-standard diagnostic ratings, scores on 66 dimensional measures of psychopathology, and measures of cognition and functioning in two different sex chromosome aneuploidies (SCAs) - Klinefelter (XXY/KS) and XYY syndrome (n=102 and 64 vs. n=74 and 60 matched XY controls, total n=300). We focus on SCAs for their high collective prevalence, informativeness regarding differential X- vs. Y-chromosome effects, and potential relevance for normative sex differences. We show that XXY/KS elevates rates for most psychiatric diagnoses as previously reported for XYY, but disproportionately so for anxiety disorders. Fine-mapping across all 66 traits provides a detailed profile of psychopathology in XXY/KS which is strongly correlated with that of XYY (r=.75 across traits) and robust to ascertainment biases, but reveals: (i) a greater penetrance of XYY than KS/XXY for most traits except mood/anxiety problems, and (ii) a disproportionate impact of XYY vs. XXY/KS on social problems. XXY/KS and XXY showed a similar coupling of psychopathology with adaptive function and caregiver strain, but not IQ. This work provides new tools for deep-phenotypic comparisons of genetic disorders in psychiatry and uses these to detail unique and shared effects of the X- and Y-chromosome on human behavior.

The activation of mGluR4 rescues parallel fiber synaptic transmission and LTP, motor learning and social behavior in a mouse model of Fragile X Syndrome

BACKGROUND

Fragile X syndrome (FXS), the most common inherited intellectual disability, is caused by the loss of expression of the Fragile X Messenger Ribonucleoprotein (FMRP). FMRP is an RNA-binding protein that negatively regulates the expression of many postsynaptic as well as presynaptic proteins involved in action potential properties, calcium homeostasis and neurotransmitter release. FXS patients and mice lacking FMRP suffer from multiple behavioral alterations, including deficits in motor learning for which there is currently no specific treatment.

METHODS

We performed electron microscopy, whole-cell patch-clamp electrophysiology and behavioral experiments to characterise the synaptic mechanisms underlying the motor learning deficits observed in Fmr1KO mice and the therapeutic potential of positive allosteric modulator of mGluR4.

RESULTS

We found that enhanced synaptic vesicle docking of cerebellar parallel fiber to Purkinje cell Fmr1KO synapses was associated with enhanced asynchronous release, which not only prevents further potentiation, but it also compromises presynaptic parallel fiber long-term potentiation (PF-LTP) mediated by β adrenergic receptors. A reduction in extracellular Ca2+ concentration restored the readily releasable pool (RRP) size, basal synaptic transmission, β adrenergic receptor-mediated potentiation, and PF-LTP. Interestingly, VU 0155041, a selective positive allosteric modulator of mGluR4, also restored both the RRP size and PF-LTP in mice of either sex. Moreover, when injected into Fmr1KO male mice, VU 0155041 improved motor learning in skilled reaching, classical eyeblink conditioning and vestibuloocular reflex (VOR) tests, as well as the social behavior alterations of these mice.

LIMITATIONS

We cannot rule out that the activation of mGluR4s via systemic administration of VU0155041 can also affect other brain regions. Further studies are needed to stablish the effect of a specific activation of mGluR4 in cerebellar granule cells.

CONCLUSIONS

Our study shows that an increase in synaptic vesicles, SV, docking may cause the loss of PF-LTP and motor learning and social deficits of Fmr1KO mice and that the reversal of these changes by pharmacological activation of mGluR4 may offer therapeutic relief for motor learning and social deficits in FXS.

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.

Developmental Coordination Disorder and Most Prevalent Comorbidities: A Narrative Review

This narrative review describes, in detail, the relationships between Developmental Coordination Disorder (DCD) and most prevalent associated comorbidities in their complexity, heterogeneity and multifactoriality. The research has been conducted on the main scientific databases, excluding single case papers. Blurred borders between the different nosographic entities have been described and advances in this field have been highlighted. In this multifaceted framework a specific profiling for co-occurring DCD, ADHD and ASD signs and symptoms is proposed, confirming the need for a multidisciplinary approach to define new diagnostic paradigms in early childhood.

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.

Evaluation of test-retest reliability and concurrent validity of the Italian version of the pediatric evaluation of disability inventory in children with down syndrome: A cross-sectional study

PURPOSE

Down Syndrome (DS) is a common genetic disorder caused by trisomy 21. Due to cognitive challenges associated with DS, individuals often experience difficulty performing activities of daily living (ADLs), at levels that can range from mild to significant. This study aimed to measure psychometric properties of the Italian version of the Pediatric Evaluation of Disability Inventory (PEDI-I) in the DS population.

METHODS

The PEDI-I was administered to children with DS. The internal consistency was examined using Cronbach's Alpha. Test-retest reliability was demonstrated by intraclass correlation coefficient (ICC) and Bland-Altman plots. The concurrent validity was evaluated with the Italian version of the Barthel Index.

RESULTS

The PEDI-I was administered to 54 children with DS. Cronbach's Alpha showed statistically significant values (0.899 -0.986). The ICC confirmed the reproducibility of the scale with a range of (0.988 -1), while Bland-Altman plots showed a smallest detectable change of (0.18-1.63). The Pearson Correlation Coefficient with the Barthel Index showed statistically significant values for all PEDI-I subscales (range 0.75-0.95).

CONCLUSION

The study provides evidence of good test-retest reliability and convergent validity when used in children with DS. Other psychometric proprieties need to be investigated in future studies.

Executive functions and adaptive behaviour in individuals with Down syndrome

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

[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.

Motor Influences on Communication: Comparisons Between Down Syndrome and Fragile X Syndrome

Motor skills, an important foundation for language and communication, are considerably delayed in children with Down syndrome (DS) and fragile X syndrome (FXS). However, the impact of these impairments on expressive and receptive communication and the phenotypic specificity of these associations remains unknown. Participants included 37 with DS and 37 age and developmentally matched children with FXS. Syndrome-specific motor and communication profiles emerged, with higher communication scores seen in the DS versus FXS on, but lower gross motor scores. Significant associations between domains of motor and communication were identified for both groups with additional phenotype-specific patterns. Findings demonstrate the importance of early motor abilities for communication in DS and FXS. Implications for phenotypic specificity and targeted intervention are discussed.

Assessing global developmental delay across instruments in minimally verbal preschool autistic children: The importance of a multi-method and multi-informant approach

Intellectual assessment in preschool autistic children bears many challenges, particularly for those who have lower language and/or cognitive abilities. These challenges often result in underestimation of their potential or exclusion from research studies. Understanding how different instruments and definitions used to identify autistic preschool children with global developmental delay (GDD) affect sample composition is critical to advance research on this understudied clinical population. This study set out to examine the extent to which using different instruments to define GDD affects sample composition and whether different definitions affect resultant cognitive and adaptive profiles. Data from the Mullen Scales of Early Learning and the Vineland Adaptive Behavior Scales-Second Edition, a parent-report tool, were analyzed in a sample of 64 autistic and 73 neurotypical children (28-69 months). Our results highlight that cognitive assessment alone should not be used in clinical or research practices to infer a comorbid diagnosis of GDD, as it might lead to underestimating autistic children's potential. Instead, using both adaptive and cognitive levels as a stratification method to create subgroups of children with and without GDD might be a promising approach to adequately differentiate them, with less risk of underestimating them.

Early intervention evidence for infants with or at risk for cerebral palsy: an overview of systematic reviews

AIM

To perform an overview of systematic reviews and more recent randomized controlled trials (RCTs) on early motor interventions in infants aged 0 to 3 years with or at risk of cerebral palsy to inform current clinical and research efforts and provide a benchmark to assess future interventions ideally initiated within the first 6 months.

METHOD

Standardized searches of the PubMed, Embase, Scopus, and Web of Science databases were conducted for systematic reviews (2009-2020) and RCTs (2015-2020).

RESULTS

From 840 unique records, 31 full texts were reviewed, yielding three systematic reviews encompassing 46 studies, 16 with comparison groups, and six additional RCTs that met the criteria. Two enrichment- and activity-based approaches had medium effect sizes on motor development, only one with low risk of bias; two others had large task-specific effect sizes but some bias concerns; and three enriched environment studies with some bias concerns had medium effect sizes on cognitive development. Most had small or no effect sizes, bias concerns, and uncertain diagnostic determinations.

INTERPRETATION

Data synthesis revealed limited data quantity and quality, and suggest, although not yet confirmed, greater benefit from early versus later intervention. Research efforts with greater early diagnostic precision and earlier intervention are accelerating, which may transform future outcomes and practices. What this paper adds For over 50% of trials within the reviews, the intervention was compared to standard care with only two showing efficacy. Similar to results in older children, constraint-induced movement therapy (CIMT) emerged as efficacious with high effect sizes. CIMT was not superior to similarly intense bimanual training or occupational therapy. Goals-Activity-Motor Enrichment intervention initiated before 5 months of age was superior to equally intense standard care. Several other enriched environment strategies promoted cognitive and/or motor development.

Is the Age of Developmental Milestones a Predictor for Future Development in Down Syndrome?

Down Syndrome (DS) is the most common genetic alteration responsible for intellectual disability, which refers to deficits in both intellectual and adaptive functioning. According to this, individuals with Down Syndrome (DS) reach developmental milestones (e.g., sitting, walking, and babbling) in the same order as their typically developing peers, but later in life. Since developmental milestones are the first blocks on which development builds, the aims of the current study are to: (i) expand the knowledge of developmental milestone acquisition; and (ii) explore the relationship between developmental milestone acquisition and later development. For this purpose 105 children/adolescents with DS were involved in this study, divided in two groups, Preschoolers (n = 39) and School-age participants (n = 66). Information on the age of acquisition of Sitting, Walking, Babbling, and Sphincter Control was collected, together with cognitive, motor, and adaptive functioning. Sitting predicted later motor development, but, with age, it became less important in predicting motor development in everyday life. Babbling predicted later language development in older children. Finally, Sphincter Control emerged as the strongest predictor of motor, cognitive, language, and adaptive skills, with its role being more evident with increasing age. Our data suggest that the age of reaching the milestones considered in the study has an influence on successive development, a role that can be due to common neural substrates, the environment, and the developmental cascade effect.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differences between children with Down syndrome and typically developing children in adaptive behaviour, executive functions and visual acuity

In children with Down syndrome (DS) development of visual, motor and cognitive functions is atypical. It is unknown whether the visual impairments in children with DS aggravate their lag in cognitive development. Visual impairment and developmental lags in adaptive behaviour and executive functions were assessed in 104 children with DS, 2–16 years, by comparing their adaptive behaviour, executive functions and visual acuity (distant and near) scores against published age-matched norm scores of typically developing children. Associations between these lags were explored. Mean (± SEM) differences to age-matched norms indicated reduced performance in DS: Vineland Screener questionnaire, − 63 ± 3.8 months; task-based Minnesota Executive Function Scale (MEFS), − 46.09 ± 2.07 points; BRIEF-P questionnaire, 25.29 ± 4.66 points; BRIEF parents’ and teachers’ questionnaire, 17.89 ± 3.92 points and 40.10 ± 3.81 points; distant and near visual acuity, 0.51 ± 0.03 LogMAR and 0.63 ± 0.03 LogMAR (near − 0.11 ± 0.04 LogMAR poorer than distant). Adaptive behaviour (Vineland-S) correlated with the severity of visual impairment (r = − 0.396). Children with DS are severely impaired in adaptive behaviour, executive functions and visual acuities (near visual acuity more severely impaired than distant visual acuity). Larger impairment in adaptive behaviour is found in children with larger visual impairment. This supports the idea that visual acuity plays a role in adaptive development.

Speech Impairments Explain Unique Variance in Adaptive Behavior Skills in Young People With Down Syndrome

Background Down syndrome (DS) is a disorder characterized by impairments in global cognitive abilities and adaptive function. In addition, individuals with DS demonstrate pronounced speech and language deficits. However, little is known about the linguistic correlates of impaired adaptive functioning in DS. Method Using the Adaptive Behavior Assessment System-Second Edition and the Children's Communication Checklist-Second Edition (CCC-2), this study investigated the unique variance in adaptive skills accounted for by speech and language impairments in individuals with DS (N = 29, M _age = 13.46). Results Pearson correlations revealed that a composite of CCC-2 structural language scales, but not pragmatic language scales, was significantly correlated with the Adaptive Behavior Assessment System-Second Edition Global Adaptive Composite, Conceptual, and Practical domains. Further investigation utilizing hierarchical regression analyses identified only the Speech scale on the CCC-2 as contributing unique variance to the prediction of adaptive behavior scores in the Global Adaptive Composite, Conceptual, and Practical domains. Conclusion Speech impairments may serve as flags to identify children with DS who are at risk for adaptive behavior deficits and reinforce the need for speech-language therapies that focus on speech for these individuals. Supplemental Material https://doi.org/10.23641/asha.13231985.

Developmental divergence: motor trajectories in children with fragile X syndrome with and without co-occurring autism

BACKGROUND

Autism spectrum disorder (ASD) is highly prevalent in fragile X syndrome (FXS), affecting 50-70% of males. Motor impairments are a shared feature across autism and FXS that may help to better characterize autism in FXS. As motor skills provide a critical foundation for various language, cognitive, and social outcomes, they may serve an important mechanistic role for autism in FXS. As such, this study aimed to identify differences in motor trajectories across direct assessment and parent-report measures of fine and gross motor development between FXS with and without autism, and typical development, while controlling for cognitive functioning.

METHODS

This prospective longitudinal study included 42 children with FXS, 24 of whom also had ASD (FXS + ASD), as well as 40 typically developing children. The Mullen Scales of Early Learning provided a direct measure of fine and gross motor skills, and the Vineland Adaptive Behavior Scales provided a measure of parent-reported fine and gross motor skills. Random slopes and random intercepts multilevel models were tested to determine divergence in developmental motor trajectories between groups when controlling for cognitive level.

RESULTS

Model results indicated the children with FXS + ASD diverged from TD children by 9-months on all measures of gross and fine motor skills, even when controlling for cognitive level. Results also indicated an early divergence in motor trajectories of fine and gross motor skills between the FXS + ASD and FXS groups when controlling for cognitive level. This divergence was statistically significant by 18 months, with the FXS + ASD showing decelerated growth in motor skills across direct observation and parent-report measures.

CONCLUSIONS

This study is the first to examine longitudinal trends in motor development in children with FXS with and without comorbid ASD using both direct assessment and parent-report measures of fine and gross motor. Furthermore, it is among the first to account for nonverbal cognitive delays, a step towards elucidating the isolated role of motor impairments in FXS with and without ASD. Findings underscore the role of motor impairments as a possible signal representing greater underlying genetic liability, or as a potential catalyst or consequence, of co-occurring autism in FXS.