summary: A new study delves into the genetic underpinnings of language development in early childhood and its implications for later cognitive abilities and neurodevelopmental disorders such as ADHD and autism spectrum disorder.
By analyzing vocabulary data from more than 17,000 children across different languages, the study reveals how genetics influences word production and comprehension from infancy to childhood, and reveals that vocabulary size is not only a marker of early language skills but also predicts future reading, writing, and cognitive ability. On learning. Potential neurodevelopmental challenges.
Interestingly, the research highlights a developmental shift in genetic associations with ADHD symptoms, suggesting that the role of genetics in language development and its impact on neurodevelopmental outcomes is complex and changes over time. This study underscores the importance of understanding the early language journey as a window into a child's future mental health and cognitive prowess.
Key facts:
- Genetic basis of language development: The study identifies genetic factors that influence vocabulary size in early childhood, and links these genetic influences to later reading, writing, cognition, and symptoms of ADHD.
- Shifting genetic associations with attention-deficit hyperactivity disorder: Initially, a larger vocabulary in childhood is associated with an increased risk of developing ADHD, but this relationship reverses in childhood, suggesting a precise role for genetics in language development and neurodevelopmental outcomes.
- Educational and therapeutic implicationsThese findings underscore the need for early interventions tailored to children's genetic predisposition, which may help prevent or mitigate cognitive and neurodevelopmental problems.
source: Max Planck Institute
Early language development is an important predictor of children's later language, reading, and learning skills. Furthermore, language learning difficulties are associated with neurodevelopmental conditions such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).
Babies usually begin speaking their first words between the ages of 10 and 15 months. At around 2 years of age, they may produce between 100 and 600 words, and understand a lot.
Each child begins on his or her own developmental path of language learning, resulting in significant individual differences. “Some of the differences in language development may be related to differences in the genetic code stored in our cells,” says lead study author Piet St. Burkin.
Word production and understanding
To understand how genetics plays a role in the development of word production and understanding in children, the team conducted a genome-wide analysis (GWAS) study of the vocabulary size of infants (15-18 months) and toddlers (24-38 months). . In early measures of vocabulary size, parents report the words their children say and/or understand from a given word list.
The team used vocabulary and genetic data from 17,298 children who spoke English, Danish, or Dutch. The number of spoken words was available for both infants and toddlers. The number of comprehensible words was only available for younger children. Later life outcomes have been studied mostly using genetic summary information from large independent consortia.
These factors included literacy (spelling, reading, and phonological awareness), cognition (general intelligence and years of education), and neurodevelopmental conditions (genetic risk for ADHD and autism spectrum disorder, as well as ADHD-related symptoms observed directly in Some of the children included in the study.
“Learning to speak” and “Speaking to learn.”
Researchers have identified multiple genetic factors that underlie vocabulary size in infancy and childhood. Consistently, genetic associations with literacy, cognition, and ADHD-related measures later in life varied during development.
Infants' and toddlers' word production was related to reading and writing abilities such as spelling, but associations with general cognition were only found in toddlers' vocabulary scores.
Young children have mastered some language fluency and may “speak to learn,” which involves higher-level cognitive processing, while the development of verbal abilities may begin early.
The team also found that in childhood, A Larger The number of words spoken has been genetically linked to a higher risk of developing ADHD and more ADHD symptoms.
However, this genetic relationship was reversed in childhood: there, A smallest The number of words understood was associated with more ADHD symptoms. It is possible that in infancy, when children are “learning to speak,” the number of words spoken captures speech-related processes.
Also, children who have a higher genetic risk of developing ADHD may tend to express themselves more. In contrast, during the “speaking to learn” phase when vocabulary size is linked to cognition, a higher risk of genetic ADHD may be associated with lower verbal and cognitive abilities.
According to St. Bourquin, “The genetic influences underlying vocabulary size change rapidly over less than 2 years during infancy and childhood. By adopting a developmental perspective, our findings provide a better understanding of the early causal processes associated with speech and language in health and disorder.”
First author Ellen Verhoff adds: “This research points to the importance of vocabulary size assessed during the first few years of life for future behavior and cognition, emphasizing the need for more data collection efforts during infancy and childhood.”
About genetics news, ADHD, and language research
author: Marjolaine Chervois
source: Max Planck Institute
communication: Marjolein Chervois – Max Planck Institute
picture: Image credited to Neuroscience News
Original search: Open access.
“Genome-wide analyzes of vocabulary size in infancy and children: associations with attention-deficit/hyperactivity disorder, literacy, and cognition-related traits” by Piet St. Bourquin et al. Biological psychiatry
a summary
Genome-wide analyzes of vocabulary size in infancy and children: associations with attention-deficit/hyperactivity disorder, literacy, and cognition-related traits.
background
The number of words children produce (expressive vocabulary) and understand (receptive vocabulary) changes rapidly during early development, partly due to genetic factors. Here, we conducted a genome-wide association study of vocabulary acquisition and investigated genetic overlap with literacy, cognition, developmental phenotypes, and neurodevelopmental conditions, including attention-deficit/hyperactivity disorder (ADHD).
Methods
We studied 37,913 parent-reported measures of vocabulary size (English, Dutch, Danish) of 17,298 children of European descent. Meta-analyses were conducted for early-stage expressive vocabulary (infancy, 15–18 months), late-stage expressive vocabulary (toddler, 24–38 months), and late-stage receptive vocabulary (toddler, 24–38 months). Subsequently, we estimated heritability based on single nucleotide polymorphisms (SNP-H2) and genetic relationships (sg) and modeling underlying factor structures using multivariate models.
results
Vocabulary size in early life was modestly heritable (SNP-H2 = 0.08-0.24). The genetic overlap between infants' expressive vocabulary and toddlers' receptive vocabulary was minimal (sg = 0.07), although each measure was moderately related to young children’s expressive vocabulary (sg = 0.69 f sg = 0.67, respectively), indicating a multifactorial genetic structure. Both infants' and toddlers' expressive vocabulary have been genetically linked to literacy (e.g., spelling: sg = 0.58 f sg = 0.79, respectively), confirming genetic similarity.
However, the genetic association between early life vocabulary, educational attainment, and intelligence only emerged during childhood (e.g., receptive vocabulary and intelligence: sg = 0.36). Genetically increased risk of ADHD has been associated with increased expressive vocabulary in infants (sg = 0.23). Multivariate genetic models in the ALSPAC (Avon Longitudinal Study of Parents and Children) cohort confirmed this finding for ADHD symptoms (eg, at age 13 years; sg = 0.54) but showed that the correlation effect was reversed for young children’s receptive vocabulary (sg = −0.74), highlighting developmental heterogeneity.
Conclusions
The genetic architecture of early life vocabulary changes during development, shaping polygenic association patterns with later-life ADHD, literacy, and cognition-related traits.
