Children with Down syndrome can benefit from language interventions; Results from a systematic review and meta-analysis

The JASPER (Joint Attention, Symbolic Play, Engagement and Regulation) Intervention in Down Syndrome: A pilot study

BACKGROUND

Children with Down syndrome (DS) often need support building language, socialization, and regulation, yet few receive behavioral intervention for this. The Joint Attention, Symbolic Play, Engagement and Regulation (JASPER) intervention holds promise as a clinician-caregiver-mediated approach.

AIMS

The aims of this pilot study were to (1) describe the behavioral phenotype of children with DS (2) quantify change in child engagement following JASPER receipt, (3) measure caregiver adoption of JASPER strategies, and (4) generate hypotheses and directions for future research.

METHODS AND PROCEDURES

Sixteen toddlers with DS and their caregivers enrolled in the study. Dyads were randomly assigned to one of two conditions: immediate intervention or waitlist control. During the COVID-19 pandemic, intervention was delivered remotely.

OUTCOMES AND RESULTS

Caregivers learned to implement JASPER strategies and pilot data suggest improvements in joint engagement and regulation during play. Case series data show individual heterogeneity of intervention response. Remote intervention delivery may be associated with greater participant retention.

CONCLUSIONS AND IMPLICATIONS

JASPER may be a viable treatment option to improve joint engagement and emotion regulation in young children with DS. Parents appear receptive to learning and implementing JASPER strategies at home. Remote JASPER delivery may improve participation in research or treatment programs.

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.

Exploring the Role of Machine Learning in Diagnosing and Treating Speech Disorders: A Systematic Literature Review

Purpose

Speech disorders profoundly impact the overall quality of life by impeding social operations and hindering effective communication. This study addresses the gap in systematic reviews concerning machine learning-based assistive technology for individuals with speech disorders. The overarching purpose is to offer a comprehensive overview of the field through a Systematic Literature Review (SLR) and provide valuable insights into the landscape of ML-based solutions and related studies.

Methods

The research employs a systematic approach, utilizing a Systematic Literature Review (SLR) methodology. The study extensively examines the existing literature on machine learning-based assistive technology for speech disorders. Specific attention is given to ML techniques, characteristics of exploited datasets in the training phase, speaker languages, feature extraction techniques, and the features employed by ML algorithms.

Originality

This study contributes to the existing literature by systematically exploring the machine learning landscape in assistive technology for speech disorders. The originality lies in the focused investigation of ML-speech recognition for impaired speech disorder users over ten years (2014-2023). The emphasis on systematic research questions related to ML techniques, dataset characteristics, languages, feature extraction techniques, and feature sets adds a unique and comprehensive perspective to the current discourse.

Findings

The systematic literature review identifies significant trends and critical studies published between 2014 and 2023. In the analysis of the 65 papers from prestigious journals, support vector machines and neural networks (CNN, DNN) were the most utilized ML technique (20%, 16.92%), with the most studied disease being Dysarthria (35/65, 54% studies). Furthermore, an upsurge in using neural network-based architectures, mainly CNN and DNN, was observed after 2018. Almost half of the included studies were published between 2021 and 2022).

Interventions for Developmental Language Delay and Disorders

BACKGROUND

Approximately 9.9 % of children present with difficulties in language development (DLD), 7.6 % without serious additional impairments and 2.3 % associated with languagerelevant comorbidities, e.g., hearing loss. Notably, in a consensus statement by experts in German-speaking countries, in the guideline presented here, and further in this article, all of these disorders are referred to as "developmental language disorders" (DLD), whereas the international consortium CATALISE only refers to those without comorbidities as DLD. DLDs are among the most commonly treated childhood disorders and, if persistent, often reduce educational and socio-economic outcome. Children in their third year of life with developmental language delay (late talkers, LT) are at risk of a later DLD.

METHODS

This German interdisciplinary clinical practice guideline reflects current knowledge regarding evidence-based interventions for developmental language delay and disorders. A systematic literature review was conducted on the effectiveness of interventions for DLD.

RESULTS

The guideline recommends parent training (Hedges g = 0.38 to 0.82) for LTs with expressive language delay, language therapy (Cohen's d = -0.20 to 0.90) for LTs with additional receptive language delay or further DLD risk factors, phonological or integrated phonological treatment methods (Cohen's d = 0.89 to 1.04) for phonological speech sound disorders (SSDs), a motor approach for isolated phonetic SSDs (non-DLD), and for lexical-semantic and morpho-syntactic impairments combinations of implicit and explicit intervention approaches (including input enrichment, modeling techniques, elicitation methods, creation of production opportunities, metalinguistic- approaches, visualizations; Cohen's d = 0.89-1.04). Recom mendations were also made for DLD associated with pragmatic-communicative impairment, bi-/ multilingualism, hearing loss, intellectual disability, autism-spectrum disorders, selective mutism, language- relevant syndromes or multiple disabilities, and for intensive inpatient language rehabilitation.

CONCLUSION

Early parent- and child-centered speech and language intervention implementing evidence-based intervention approaches, frequency, and settings, combined with educational language support, can improve the effectiveness of management of developmental language delay and disorders.

Transcranial Direct Current Stimulation in neurogenetic syndromes: new treatment perspectives for Down syndrome?

This perspective review aims to explore the potential neurobiological mechanisms involved in the application of transcranial Direct Current Stimulation (tDCS) for Down syndrome (DS), the leading cause of genetically-based intellectual disability. The neural mechanisms underlying tDCS interventions in genetic disorders, typically characterized by cognitive deficits, are grounded in the concept of brain plasticity. We initially present the neurobiological and functional effects elicited by tDCS applications in enhancing neuroplasticity and in regulating the excitatory/inhibitory balance, both associated with cognitive improvement in the general population. The review begins with evidence on tDCS applications in five neurogenetic disorders, including Rett, Prader-Willi, Phelan-McDermid, and Neurofibromatosis 1 syndromes, as well as DS. Available evidence supports tDCS as a potential intervention tool and underscores the importance of advancing neurobiological research into the mechanisms of tDCS action in these conditions. We then discuss the potential of tDCS as a promising non-invasive strategy to mitigate deficits in plasticity and promote fine-tuning of the excitatory/inhibitory balance in DS, exploring implications for cognitive treatment perspectives in this population.

Oral language interventions can improve language outcomes in children with neurodevelopmental disorders: A systematic review and meta-analysis

Background

Young people who fail to develop language as expected face significant challenges in all aspects of life. Unfortunately, language disorders are common, either as a distinct condition (e.g., Developmental Language Disorder) or as a part of another neurodevelopmental condition (e.g., autism). Finding ways to attenuate language problems through intervention has the potential to yield great benefits not only for the individual but also for society as a whole.

Objectives

This meta-analytic review examined the effect of oral language interventions for children with neurodevelopmental disorders.

Search Methods

The last electronic search was conducted in April 2022.

Selection Criteria

Intervention studies had to target language skills for children from 2 to 18 years of age with Developmental Language Disorder, autism, intellectual disability, Down syndrome, Fragile X syndrome, and Williams syndrome in randomised controlled trials or quasi-experimental designs. Control groups had to include business-as-usual, waiting list, passive or active conditions. However, we excluded studies in which the active control group received a different type, delivery, or dosage of another language intervention. Eligible interventions implemented explicit and structured activities (i.e., explicit instruction of vocabulary, narrative structure or grammatical rules) and/or implicit and broad activities (i.e., shared book reading, general language stimulation). The intervention studies had to assess language skills in receptive and/or expressive modalities.

Data Collection and Analysis

The search provided 8195 records after deduplication. Records were screened by title and abstract, leading to full-text examinations of 448 records. We performed Correlated and Hierarchical Effects models and ran a retrospective power analysis via simulation. Publication bias was assessed via p-curve and precision-effect estimate.

Main Results

We examined 38 studies, with 46 group comparisons and 108 effects comparing pre-/post-tests and eight studies, with 12 group comparisons and 21 effects at follow-up. The results showed a mean effect size of d = 0.27 at the post-test and d = 0.18 at follow-up. However, there was evidence of publication bias and overestimation of the mean effects. Effects from the meta-analysis were significantly related to these elements: (1) receptive vocabulary and omnibus receptive measures showed smaller effect sizes relative to expressive vocabulary, grammar, expressive and receptive discourse, and omnibus expressive tests; and (2) the length of the intervention, where longer sessions conducted over a longer period of time were more beneficial than brief sessions and short-term interventions. Neither moderators concerning participants' characteristics (children's diagnosis, diagnostic status, age, sex, and non-verbal cognitive ability and severity of language impairment), nor those regarding of the treatment components and implementation of the language interventions (intervention content, setting, delivery agent, session structure of the intervention or total number of sessions) reached significance. The same occurred to indicators of study quality. The risk of bias assessment showed that reporting quality for the studies examined in the review was poor.

Authors’ Conclusions

In sum, the current evidence base is promising but inconclusive. Pre-registration and replication of more robust and adequately powered trials, which include a wider range of diagnostic conditions, together with more long-term follow-up comparisons, are needed to drive evidence-based practice and policy.

Motor-language links in children with Down syndrome: a scoping review to revisit the literature with a developmental cascades lens

Background

Children with Down syndrome (DS) typically have motor and language needs. Improving function is a shared goal for the rehabilitation therapy team, however physical therapy, occupational therapy, and speech-language pathology professionals treat patients differently. This difference in care may mask developmental cascades whereby changes in one domain (e.g., motor) can have seemingly unexpected effects on another domain (e.g., language).

Objective

This scoping review identified papers where motor and language data have been reported together in children with DS and reinterpreted findings from a developmental cascades lens.

Design

Online databases were used to identify 413 papers published before October 2021 from which 33 papers were retained that reported both motor (gross and/or fine) and language (expressive and/or receptive) data in individuals with DS with a chronological age of 0-18 years.

Results

The majority of papers (79%) that reported motor and language data in children with DS did not examine their link, while 12% analyzed motor-language links, but using a cross-sectional or retrospective design. Only three papers (9%) utilized a longitudinal design to examine predictive links.

Conclusion

Motor functioning and language functioning have often been reported together, but not analyzed together, in studies of children with DS. The few studies that did analyze motor-language links largely replicated findings from other developmental populations where motor gains were positively linked to language gains. Analyzing links between domains when such data is available is needed to fully characterize developmental cascades in DS and may have broad clinical implications.

Guidance for Increasing Primary Study Inclusion and the Usability of Data in Meta-Analysis: A Reporting Tutorial

Meta-analyses can be used to comprehensively summarize the state of a given literature base, understand development and relations between constructs, and synthesize intervention effects to identify "what works for whom," all of which can directly inform research, practice, and policy. In this tutorial, we first argue that data reporting in primary studies can meaningfully affect the results of meta-analyses and, most importantly, the subsequent interpretations and use of the findings in research, practice, and policy in speech, language, and hearing sciences. Though reporting guidelines have been well established for the results of meta-analyses, there is limited focus on the essentials for primary study reporting that allow for inclusion in meta-analyses. To this end, we provide guidance for primary study authors to ensure their studies can maximize their contributions to research syntheses and, specifically, to meta-analyses. We discuss current and ongoing issues related to reporting, provide data-based examples of instances where lack of reporting or transparency has rendered a study ineligible from inclusion in a meta-analysis, encourage editorial teams and peer reviewers to be flexible in the inclusion of supplemental data reporting based on journal requirements and limits, and suggest being explicit and earnest about why these requests are important to advancing the field. Supplemental Material: https://doi.org/10.23641/asha.23117996.

Shared book reading as a context for language intervention for children with Down syndrome: a mini-review

Acquiring language and communication skills is one of the biggest challenges for children with Down syndrome (DS). However, few evidence-based interventions exist to enhance the development of language and communication in this population. Shared book reading (SBR) is well-established as an effective intervention for language and communication development of typically developing children, and evidence of the possible effectiveness of this approach for those at risk of language difficulties is emerging. This paper provides a mini-review of the existing evidence for SBR in relation to language and communication outcomes for young children with DS. A systematic literature search was conducted with the following inclusion criteria: children with DS aged 0-6;11 years, SBR, language or communication outcomes. The results show that interventions which incorporate SBR strategies are associated with improved language and communication outcomes for young children with DS, improved parental sensitivity, and continuing implementation of SBR strategies following intervention instruction. However, evidence is limited in scope, of low quality, including mostly single case studies, with only one study having a control group. We conclude that although SBR may hold promise as a possible intervention, further research is essential to establish what specific components of SBR intervention are most effective for young children with DS and what further adaptations are needed to accommodate the cognitive profile and variability within this population.

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.

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.

A systematic review of speech, language and communication interventions for children with Down syndrome from 0 to 6 years

BACKGROUND

Speech and language acquisition can be a challenge for young children with Down syndrome (DS), and while early intervention is important, we do not know what early interventions exist and how effective they may be.

AIMS

To systematically review existing early speech, language and communication interventions for young children with DS from birth up to 6 years, and to investigate their effectiveness in improving speech, language and communication outcomes in children with DS. Other outcomes are changes in parental behaviour and their responsiveness METHODS & PROCEDURES: We conducted a systematic search of relevant electronic databases to identify early intervention studies targeting speech, language and communication outcomes in children with DS published up to May 2020. A total of 11 studies that met the inclusion criteria were synthesized and appraised for quality using the PEDro-P scale. There were a total of 242 children. We identified three types of intervention: communication training and responsive teaching, early stimulation programme, and dialectic-didactic approach.

MAIN CONTRIBUTION

The findings from nine out of the 11 studies reported positive outcomes for children's language and communication up to 18 months following the intervention. All nine studies reported interventions that were co-delivered by parents and clinicians. However, there was also a de-accelerated growth in requesting behaviours in the intervention group reported by one study as well as a case of no improvement for the intervention group. Three studies provided some evidence of improvements to parent outcomes, such as increased parental language input and increased responsiveness. However, there was a moderate to high risk of bias for all studies included.

CONCLUSIONS

The findings from this review suggest that interventions that have high dosage, focus on language and communication training within a naturalistic setting, and are co-delivered by parents and clinicians/researchers may have the potential to provide positive outcomes for children with DS between 0 and 6 years of age. Due to the limited number of studies, limited heterogeneous data and the moderate to high risk of bias across studies, there is an urgent need for higher quality intervention studies in the field to build the evidence base.

WHAT THIS PAPER ADDS

What is already known on the subject Speech and language acquisition is usually delayed in children with DS, yet there are currently no standard interventions for children under 6. A number of research-based interventions exist in the literature, yet it is unknown how effective these are. What this study adds to existing knowledge This is the first systematic review that specifically and exclusively focuses on parent- and non-parent-mediated speech, language and communication interventions for children with DS between 0 and 6 years of age. It complements three existing recent reviews, each of which has a slightly different focus. The previously published reviews have covered only parent-mediated interventions, excluding interventions not mediated by parents, have reviewed interventions including children and adults, without any mention of what early interventions may be like or how effective these may be for young children with DS, have not always assessed risk of bias or have focused specifically on language interventions excluding those focusing on speech articulation or pre-linguistic skills. The findings from the current review suggest that interventions that have high dosage focus on language and communication training within a naturalistic setting and are co-delivered by parents and clinicians/researchers may have the potential to provide positive outcomes for children with Diwn syndrome from 0 to 6. We acknowledge that the current evidence base comes from studies with moderate to high risk of bias, hence our conclusions are not definitive. What are the potential or actual clinical implications of this work? Speech and language therapists will have synthesized information and a quick reference point on what type of interventions exist for children with DS under the age of 6, and evidence of which intervention approaches may be promising in terms of providing positive outcomes. However, it is acknowledged that, due to the limited number of studies and the moderate to high risk of bias inherent in the evidence, there is an urgent need for higher quality intervention studies in the field to build the evidence base.

Experientially based narrative instruction: A neurocognitive perspective

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Maternal Use of Decontextualized and Contextualized Talk: An In-Depth Investigation of Early Parent-Child Interactions in Down Syndrome

Purpose The goal of this study was to characterize and quantify maternal use of decontextualized and contextualized input during mother-child interactions including young children with Down syndrome (DS). Method Participants included 22 mother-child dyads with DS (M age = 42.8 months) and 22 mother-child dyads with typical development (M age = 44.0 months). Parent-child language samples were collected during free-play, book reading, and snack time, and coded for maternal decontextualized (i.e., pretend, explanatory, and narrative talk) and contextualized input (i.e., descriptions, conversation, praise, questions, and directives). Results Mothers of children with DS used a larger proportion of pretend talk compared to other types of decontextualized input and also used a larger proportion of questions, conversation, and descriptions compared to other types of contextualized language. Mothers of children with DS generally used a smaller proportion of decontextualized input compared to mothers of children with typical development, with the exception of pretend talk. Maternal decontextualized input was not related to children's age or language ability in DS. Conclusions Findings shed new light on the early language environments of children with DS, providing important insight into the ways that mothers of children with DS are incorporating decontextualized and contextualized talk into early mother-child conversations. Additional implications and future directions are discussed.

Spoken language outcome measures for treatment studies in Down syndrome: feasibility, practice effects, test-retest reliability, and construct validity of variables generated from expressive language sampling

BACKGROUND

The purpose of this study was to evaluate expressive language sampling (ELS) as a procedure for generating spoken language outcome measures for treatment research in Down syndrome (DS). We addressed (a) feasibility, (b) practice effects across two short-term administrations, (c) test-retest reliability across two short-term administrations, (d) convergent and discriminant construct validity, and (e) considered comparisons across the conversation and narration contexts.

METHOD

Participants were 107 individuals with DS between 6 and 23 years of age who presented with intellectual disability (IQ < 70). The utility of ELS procedures designed to collect samples of spoken language in conversation and narration were evaluated separately. Variables of talkativeness, vocabulary, syntax, utterance planning, and articulation quality, derived from transcripts segmented into C-units (i.e., an independent clause and its modifiers), were considered. A 4-week interval was used to assess practice effects and test-retest reliability. Standardized direct assessments and informant report measures were collected to evaluate construct validity of the ELS variables.

RESULTS

Low rates of noncompliance were observed; youth who were under 12 years of age, had phrase-level speech or less, and had a 4-year-old developmental level or less were at particular risk for experiencing difficulty completing the ELS procedures. Minimal practice effects and strong test-retest reliability across the 4-week test-retest interval was observed. The vocabulary, syntax, and speech intelligibility variables demonstrated strong convergent and discriminant validity. Although significant correlations were found between the variables derived from both the conversation and narration contexts, some differences were noted.

CONCLUSION

The ELS procedures considered were feasible and yielded variables with adequate psychometric properties for most individuals with DS between 6 and 23 years old. That said, studies of outcome measures appropriate for individuals with DS with more limited spoken language skills are needed. Context differences were observed in ELS variables suggest that comprehensive evaluation of expressive language is likely best obtained when utilizing both contexts.

The Potential Role of miRNAs as Predictive Biomarkers in Neurodevelopmental Disorders

Neurodevelopmental disorders are defined as a set of abnormal brain developmental conditions marked by the early childhood onset of cognitive, behavioral, and functional deficits leading to memory and learning problems, emotional instability, and impulsivity. Autism spectrum disorder, attention-deficit/hyperactivity disorder, Tourette syndrome, fragile X syndrome, and Down's syndrome are a few known examples of neurodevelopmental disorders. Although they are relatively common in both developed and developing countries, very little is currently known about their underlying molecular mechanisms. Both genetic and environmental factors are known to increase the risk of neurodevelopmental disorders. Current diagnostic and screening tests for neurodevelopmental disorders are not reliable; hence, individuals with neurodevelopmental disorders are often diagnosed in the later stages. This negatively affects their prognosis and quality of life, prompting the need for a better diagnostic biomarker. Recent studies on microRNAs and their altered regulation in diseases have shed some light on the possible role they could play in the development of the central nervous system. This review attempts to elucidate our current understanding of the role that microRNAs play in neurodevelopmental disorders with the hope of utilizing them as potential biomarkers in the future.

Differences and Similarities in Predictors of Expressive Vocabulary Development between Children with Down Syndrome and Young Typically Developing Children

The purpose of this study was to examine potential differences in the predictors of expressive vocabulary development between children with Down syndrome and typically developing children to support preparation for intervention development. An age cohort of 43 children with Down syndrome and 57 typically developing children with similar nonverbal mental age levels were assessed at three time points. Linear mixed models were used to investigate the predictors of expressive vocabulary over time. Both groups achieved progress in expressive vocabulary. The typically developing children had steeper growth than the children with Down syndrome (1.38 SD vs. 0.8 SD, p < 0.001). In both groups, receptive vocabulary, auditory memory, and the home literacy environment were significant predictors of development. In the children with Down syndrome, the phonological awareness and oral motor skills were also significant. Group comparisons showed that receptive vocabulary, auditory memory and oral motor skills were stronger predictors in the children with Down syndrome than in the typically developing children. These results indicate that children with Down syndrome are more vulnerable when it comes to risk factors that are known to influence expressive vocabulary than typically developing children. Children with Down syndrome therefore require early broad-based expressive vocabulary interventions.