1. Genome-wide Analyses of Vocabulary Size in Infancy and Toddlerhood: Associations With Attention-Deficit/Hyperactivity Disorder, Literacy, and Cognition-Related Traits
- Author
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Verhoef, E, Allegrini, AG, Jansen, PR, Lange, K, Wang, CA, Morgan, AT, Ahluwalia, TS, Symeonides, C, EAGLE Working Group, Eising, E, Franken, M-C, Hypponen, E, Mansell, T, Olislagers, M, Omerovic, E, Rimfeld, K, Schlag, F, Selzam, S, Shapland, CY, Tiemeier, H, Whitehouse, AJO, Saffery, R, Bønnelykke, K, Reilly, S, Pennell, CE, Wake, M, Cecil, CAM, Plomin, R, Fisher, SE, St Pourcain, B, Verhoef, E, Allegrini, AG, Jansen, PR, Lange, K, Wang, CA, Morgan, AT, Ahluwalia, TS, Symeonides, C, EAGLE Working Group, Eising, E, Franken, M-C, Hypponen, E, Mansell, T, Olislagers, M, Omerovic, E, Rimfeld, K, Schlag, F, Selzam, S, Shapland, CY, Tiemeier, H, Whitehouse, AJO, Saffery, R, Bønnelykke, K, Reilly, S, Pennell, CE, Wake, M, Cecil, CAM, Plomin, R, Fisher, SE, and St Pourcain, B
- Abstract
BACKGROUND: The number of words children produce (expressive vocabulary) and understand (receptive vocabulary) changes rapidly during early development, partially due to genetic factors. Here, we performed a meta-genome-wide association study of vocabulary acquisition and investigated polygenic overlap with literacy, cognition, developmental phenotypes, and neurodevelopmental conditions, including attention-deficit/hyperactivity disorder (ADHD). METHODS: We studied 37,913 parent-reported vocabulary size measures (English, Dutch, Danish) for 17,298 children of European descent. Meta-analyses were performed for early-phase expressive (infancy, 15-18 months), late-phase expressive (toddlerhood, 24-38 months), and late-phase receptive (toddlerhood, 24-38 months) vocabulary. Subsequently, we estimated single nucleotide polymorphism-based heritability (SNP-h2) and genetic correlations (rg) and modeled underlying factor structures with multivariate models. RESULTS: Early-life vocabulary size was modestly heritable (SNP-h2 = 0.08-0.24). Genetic overlap between infant expressive and toddler receptive vocabulary was negligible (rg = 0.07), although each measure was moderately related to toddler expressive vocabulary (rg = 0.69 and rg = 0.67, respectively), suggesting a multifactorial genetic architecture. Both infant and toddler expressive vocabulary were genetically linked to literacy (e.g., spelling: rg = 0.58 and rg = 0.79, respectively), underlining genetic similarity. However, a genetic association of early-life vocabulary with educational attainment and intelligence emerged only during toddlerhood (e.g., receptive vocabulary and intelligence: rg = 0.36). Increased ADHD risk was genetically associated with larger infant expressive vocabulary (rg = 0.23). Multivariate genetic models in the ALSPAC (Avon Longitudinal Study of Parents and Children) cohort confirmed this finding for ADHD symptoms (e.g., at age 13; rg = 0.54) but showed that the association effect reversed for
- Published
- 2023