Developmental language disorder - a comprehensive study of more than 46,000 individuals

Word Learning in Bilingual Children at Risk for Developmental Language Disorder

PURPOSE

The purpose of this study was to compare the novel word learning skills between Cantonese-English bilingual children at risk for developmental language disorder (DLD) and their typically developing (TD) peers.

METHOD

Participants were 24 Cantonese-English bilingual preschool children at risk for DLD and 38 TD children. Each participant was presented with eight novel words in Cantonese (first language [L1]) and eight in English (second language [L2]) over eight weekly sessions. Children's existing lexical knowledge was measured using the moving-average number of different words in language samples in L1 and L2.

RESULTS

Bilingual children at risk for DLD were scored lower than their TD peers for both languages over time. The role of lexical knowledge in children's word learning differed between the TD and DLD groups: Lexical knowledge in L1 was a predictor of L1 word learning in TD children, while lexical knowledge in L2 predicted L2 word learning in children at risk for DLD. In addition, significant cross-linguistic effects were found from L2 to L1 for both groups.

CONCLUSIONS

This study underscores the complexity of novel word learning in bilingual children at risk for DLD. Clinically, these findings suggest the value of tracking learning trajectories in bilingual children across both languages.

Language, Motor Ability and Related Deficits in Children at Familial Risk of Schizophrenia or Bipolar Disorder

BACKGROUND

It is known that impairments in linguistic ability and motor function tend to co-occur in children, and that children from families with parental mental illness such as schizophrenia tend to perform poorly in both domains, but the exact nature of these links has not yet been fully elucidated.

DESIGN

In this study, we leveraged the first wave of the Danish High Risk and Resilience Study (VIA 7), which includes both genetic data and measures covering multiple developmental domains. The VIA 7 cohort comprises 522 7-year-old children born to parents with schizophrenia (N = 202), bipolar disorder (N = 120) or neither (N = 200). We investigated the relationships between linguistic ability and motor function using correlation and regression analyses, focusing on developmental coordination disorder (DCD) and specific language impairment (SLI) and their potential associations with the three risk groups.

RESULTS

We found significant correlations between most measures of language and motor function and significant associations of DCD and SLI with language and movement measures, respectively, the largest effect being that of DCD on receptive language, with a significant interaction effect: DCD was associated with poorer performance in children from schizophrenia families compared to bipolar disorder and control families. Both disorders showed higher prevalence among children with familial high risk of mental illness. We did not find significant evidence of genetic overlap between DCD and SLI.

CONCLUSIONS

Our results suggest strong links between the domains of motor function and linguistic ability. Children of parents with schizophrenia are at high risk of comorbid language and movement disorders.

Developmental language disorder - heritability and genetic correlations with other disorders affecting language

Developmental language disorder (DLD) is a neurodevelopmental disorder primarily affecting language in the absence of a known biomedical condition, which may have a large impact on a person's life and mental health. Family-based studies indicate a strong genetic component in DLD, but genetic studies of DLD are scarce. In this study we estimated the heritability of DLD and its genetic correlations with related disorders and traits in sample of >25,000 individuals from the Danish Blood Donor Study for whom we had both genotype data and questionnaire data on language disorder and language support. We estimated SNP-based heritabilities for DLD and genetic correlations with disorders which may involve spoken language deficits and traits related to spoken language. We found significant heritability estimates for DLD ranging from ∼27 % to ∼52 %, depending on the method used. We found no significant evidence for genetic correlation with the investigated disorders or traits, although the strongest effect was observed for a negative genetic correlation between DLD and nonword repetition ability. To our knowledge, this study reports the first significant heritability estimate for DLD from molecular genetic data.

Autism spectrum disorder, social pragmatic communication disorder, developmental language disorder- multimorbidity or mutual exclusivity?

Diagnostic confusion commonly arises when assessing for social communicative dysfunction. Clinicians are tasked to differentiate ASD, social pragmatic disorder and developmental language disorders, which can be difficult to contemplate on clinical grounds. Here, authors provide some helpful clinical tips to tease it out.

Prevalence and heritability of parental-reported speech and/or language difficulties in a Swedish population-based twin sample

Background

Research on genetic and environmental influences on speech and/or language difficulties (SaLD) is sparse, with inconsistent heritability estimates. We aimed to estimate the prevalence of parental reported SaLD and the relative contributions of genetic and environmental factors for the phenotype using a Swedish population-based twin sample. We hypothesized that there would be a stronger genetic than environmental effect on SaLD.

Methods

Data were collected from The Child and Adolescent Twin Study in Sweden. The study sample included 16,774 twin pairs (16,946 males, 16,602 females), of which 5141 were monozygotic, 5861 dizygotic (DZ), and 5772 opposite-sex DZ pairs. The language items in the Autism-Tics, Attention-Deficit Hyperactivity Disorder, and other Comorbidities inventory were used to categorize individuals as having parental-reported SaLD. A classical twin design was used to estimate the relative contribution of genetic and environmental factors to the liability of SaLD.

Results

The prevalence of SaLD was 7.85% (95% confidence interval (CI) [7.57%-8.15%]) and 7.27% (95% CI [6.99%-7.55%]) when excluding individuals with autism and intellectual disability (ID). We also found that SaLD were significantly more prevalent in males than females with a ratio of 2:1. The heritability was estimated to be 75% (95% CI [67%-83%]) for SaLD. Shared environment played a significant role with an estimated contribution of 22% (95% CI [14%-30%]). The heritability estimate was reduced to 70% but with overlapping CI when excluding individuals with autism and ID.

Conclusions

We provide evidence that SaLD is common in the population and under strong genetic influence. Future studies should focus on mapping the genetic architecture of SaLD and related disorders.

Sentence Repetition as a Diagnostic Tool for Developmental Language Disorder: A Systematic Review and Meta-Analysis

PURPOSE

This systematic review and multilevel meta-analysis examines the accuracy of sentence repetition (SR) tasks in distinguishing between typically developing (TD) children and children with developmental language disorder (DLD). It explores variation in the way that SR tasks are administered and/or evaluated and examines whether variability in the reported ability of SR to detect DLD is related to these differences.

METHOD

Four databases were searched to identify studies that had used an SR task on groups of monolingual children with DLD and TD children. Searches produced 3,459 articles, of which, after screening, 66 were included in the systematic review. A multilevel meta-analysis was then conducted using 46 of these studies. Multiple preregistered subgroup analyses were conducted in order to explore the sources of heterogeneity.

RESULTS

The systematic review found a great deal of methodological variation, with studies spanning 19 languages, 39 SR tasks, and four main methods of production scoring. There was also variation in study design, with different sampling (clinical and population sampling) and matching (age and language matching) methods. The overall meta-analysis found that, on average, TD children outperformed children with DLD on the SR tasks by 2.08 SDs. Subgroup analyses found that effect size only varied as a function of the matching method and language of the task.

CONCLUSIONS

Our results indicate that SR tasks can distinguish children with DLD from both age- and language-matched samples of TD children. The usefulness of SR appears robust to most kinds of task and study variation.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25864405.

Listening and Processing Skills in Young School Children with a History of Developmental Phonological Disorder

There is a lack of longitudinal studies on the broad-based outcomes in children with Developmental Phonological Disorder (DPD). The aim of this study was to investigate listening and processing skills in a clinical sample of 7-to-10-year-old children diagnosed with DPD in their preschool years and compare these to same-aged typically developing (TD) children. The Evaluation of Children's Listening and Processing Skills (ECLiPS) was completed by parents of 115 children with DPD and by parents of 46 TD children. The total ECLiPS mean score, and the five subscale mean scores, the proportion of children with clinically significant difficulties (≤10th percentile), and the proportion of children with co-occurrence of clinically significant difficulties on more than one subscale, were calculated. Results showed that the ECLiPS mean scores did not differ between the groups. There was no difference between groups regarding language and literacy, but a higher proportion of children with DPD than TD had difficulties in the total score, speech, and auditory processing, environmental and auditory sensitivity, and pragmatic and social skills. In addition, 33.9% of children with DPD had clinically significant difficulties in two or more subscales compared to 10.9% of TD children.

Number agreement processing in adolescents with and without developmental language disorder (DLD): evidence from event-related brain potentials

In morphologically richer languages, including French, one must learn the specific properties of number agreement in order to understand the language, and this learning process continues into adolescence. This study examined similarities and differences between French-speaking adolescents with and without developmental language disorder (DLD) when processing number agreement, and investigated how morpho-syntactic regularity affected language processing. Using event-related potentials (ERP) and only grammatical sentences with audio-visual mismatches, we studied ERP correlates to three types of number agreement: (1) regular determiner agreement in noun phrases, (2) regular subject-verb plural liaison, and (3) irregular subject-verb agreement. We also included a lexico-semantic mismatch condition to investigate lexico-semantic processing in our participants. 17 adolescents with DLD (M = 14.1 years) and 20 (pre)teens with typical language (TL, M = 12.2 years) participated in the study. Our results suggest three patterns. First, French-speaking teenagers without DLD are still consolidating their neurocognitive processing of morpho-syntactic number agreement and generally display ERP profiles typical of lower language proficiency than adult native speakers. Second, differences in morphosyntactic processing between teenagers with and without DLD seem to be limited to rule-based (regular) number agreement. Third, there is little evidence for corresponding differences in lexico-semantic processing.

Innovative Family-Based Genetically Informed Series of Analyses of Whole-Exome Data Supports Likely Inheritance for Grammar in Children with Specific Language Impairment

Individuals with specific language impairment (SLI) struggle with language acquisition despite average non-verbal intelligence and otherwise typical development. One SLI account focuses on grammar acquisition delay. The current study aimed to detect novel rare genetic variants associated with performance on a grammar assessment, the Test of Early Grammatical Impairment (TEGI), in English-speaking children. The TEGI was selected due to its sensitivity and specificity, consistently high heritability estimates, and its absence from all but one molecular genetic study. We performed whole exome sequencing (WES) in eight families with SLI (n = 74 total) and follow-up Sanger sequencing in additional unrelated probands (n = 146). We prioritized rare exonic variants shared by individuals with low TEGI performance (n = 34) from at least two families under two filtering workflows: (1) novel and (2) previously reported candidate genes. Candidate variants were observed on six new genes (PDHA2, PCDHB3, FURIN, NOL6, IQGAP3, and BAHCC1), and two genes previously reported for overall language ability (GLI3 and FLNB). We specifically suggest PCDHB3, a protocadherin gene, and NOL6 are critical for ribosome synthesis, as they are important targets of SLI investigation. The proposed SLI candidate genes associated with TEGI performance emphasize the utility of precise phenotyping and family-based genetic study.