Associations Between the 2D:4D Proxy Biomarker for Prenatal Hormone Exposures and Symptoms of Developmental Language Disorder

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.

Diagnosis of Developmental Language Disorder in Research Studies

Purpose The aim of this study was to investigate the extent to which researchers in the field of developmental language disorder are utilizing validated methods to diagnose their research participants. Method We examined 90 research articles published from 2015 to 2019 that included English-speaking participants from the United States who were identified as having a developmental language disorder or specific language impairment. From these articles, we identified the tests and measures used to identify participants and classify them as healthy or impaired. We then consulted the test manuals and the literature to find information on sensitivity and specificity of the test and the evidence-based cut score that maximized identification accuracy. Results Of the 90 articles examined, 38 (42%) were found to reflect validated diagnostic methods, and 51 (58%) did not. Conclusion Our results illustrate that validated methods are used less than half of the time even by those who should have a high level of expertise and despite calls for increasing scientific rigor in research practices.

2D:4D ratios as an indicator of intrauterine androgen exposure in children who stutter

AIM

We aimed to explore whether there is a relationship between stuttering and digit ratio (2D:4D), which is thought to be a marker of prenatal testosterone exposure.

METHODS

We evaluated a total of 90 children who stutter (CWS; n = 40 mild-to-moderate and n = 50 severe stutters) and 40 healthy peers (CWNS) as controls. We used the Clinical Global Impression-Severity (CGIS) scale to measure the severity of stuttering. We measured the lengths of index finger (2D) and ring finger (4D) of both hands directly and divided to calculate 2D:4D ratio. The difference between the right and the left hand 2D:4D ratio (D_R-L) was also calculated.

RESULT

Significant difference was found in right 2D:4D and the mean D_R-L between the CWS and CWNS groups. Right 2D:4D was significantly lower in stuttering boys than in control boys, and in stuttering girls than control girls. Also, D_R-L was significantly lower in stuttering boys than control boys. In ANOVA, there were significant differences between the mild-to-moderate, severe stuttering and control groups in terms of right 2D:4D and D_R-L. Right hand 2D:4D and D_R-L decreased from controls to severe stutterers.

CONCLUSION

Our results suggest that lower right 2D:4D and D_R-L were related to the presence and severity of stuttering in children, i.e. CWS had lower 2D:4D and D_R-L than CWNS. Further large-scale prospective studies are needed to clarify the reliability of 2D:4D ratio as an indicator of fetal sex hormone exposure level and its relation with the presence and severity of stuttering in children.

[Use of the 2D:4D digit ratio as a biological marker of specific language disorders]

INTRODUCTION

The finding of biological markers of specific language impairment would facilitate their detection and early intervention. In this sense, the 2D:4D finger ratio is considered an indirect indicator of prenatal exposure to testosterone. Previous studies have related it to linguistic competence and aggressive behaviour, and could be a candidate for a biological marker of language impairment. The aim was to compare the value of the 2D:4D ratio in children with Specific Language Impairment (SLI) with those of children with typical language development, as well as to establish to what extent this biological index correlates with the behaviour (linguistic, cognitive, social,...) in both groups.

SUBJECTS AND METHODS

2D:4D ratio, language, cognition and social behaviour were compared in a group of children with SLI (n=15), with a group of children without language difficulties (n=16) of the same age (between 5-8 years), gender (male), and socio-cultural level.

RESULTS

Children with SLI showed significantly higher values of 2D:4D ratio of the right hand, and a negative correlation between this ratio and their linguistic competence. Although the children with SLI showed impaired adaptive abilities, but not more aggressive behaviour, these measurements did not correlate with the 2D:4D index. Nevertheless, social behaviour correlated with language and cognition competence.

CONCLUSIONS

A higher value of the biological 2D:4D ration (lower intrauterine exposure to testosterone) seems to be associated with language difficulties in boys with SLI, but not with their behavioural difficulties. Their behavioural difficulties seem to be a consequence of their linguistic difficulties and their level of cognition.