Exploring the Genetic and Environmental Etiologies of Phonological Awareness, Morphological Awareness, and Vocabulary Among Chinese–English Bilingual Children: The Moderating Role of Second Language Instruction

Cumulative genetic score of KIAA0319 affects reading ability in Chinese children: moderation by parental education and mediation by rapid automatized naming

KIAA0319, a well-studied candidate gene, has been shown to be associated with reading ability and developmental dyslexia. In the present study, we investigated whether KIAA0319 affects reading ability by interacting with the parental education level and whether rapid automatized naming (RAN), phonological awareness and morphological awareness mediate the relationship between KIAA0319 and reading ability. A total of 2284 Chinese children from primary school grades 3 and 6 participated in this study. Chinese character reading accuracy and word reading fluency were used as measures of reading abilities. The cumulative genetic risk score (CGS) of 13 SNPs in KIAA0319 was calculated. Results revealed interaction effect between CGS of KIAA0319 and parental education level on reading fluency. The interaction effect suggested that individuals with a low CGS of KIAA0319 were better at reading fluency in a positive environment (higher parental educational level) than individuals with a high CGS. Moreover, the interaction effect coincided with the differential susceptibility model. The results of the multiple mediator model revealed that RAN mediates the impact of the genetic cumulative effect of KIAA0319 on reading abilities. These findings provide evidence that KIAA0319 is a risk vulnerability gene that interacts with environmental factor to impact reading abilities and demonstrate the reliability of RAN as an endophenotype between genes and reading associations.

Complexity and cross-linguistic transfer in intervention for Spanish–English bilingual children with speech sound disorder

With bilingual children, intervention for speech sound disorders must consider both of the child’s phonological systems, which are known to interact with each other in development. Further, cross-linguistic generalization following intervention for bilingual children with speech sound disorders (i.e. the impact of treatment in one language on the other) has been documented to varying degrees in some prior studies. However, none to date have documented the cross-linguistic impact of treatment with complex targets (e.g. consonant clusters) for bilingual children. Because complex phonological targets have been shown to induce system-wide generalization within a single language, the potential for bilingual children to generalize learning across languages could impact the efficiency of intervention in this population. This pilot intervention study examines the system-wide, cross-linguistic effects of treatment targeting consonant clusters in Spanish for two Spanish–English bilingual children with phonological disorder. Treatment was provided with 40-minute sessions in Spanish via teletherapy, three times per week for six weeks. Comprehensive phonological probes were administered in English and Spanish prior to intervention and across multiple baselines. Pre-intervention data were compared to data from probes administered during and after intervention to generate qualitative and quantitative measures of treatment outcomes and cross-linguistic generalization. Results indicate a medium effect size for system-wide generalization in Spanish (the language of treatment) and English (not targeted in treatment), for both participants (mean effect size in Spanish: 3.6; English 4.3). These findings have implications for across-language transfer and system-wide generalization in treatment for bilingual children.