Genetic and Environmental Influences on Developmental Milestones and Movement: Results From the Gemini Cohort Study

Genetic confounding in the association of early motor development with childhood and adolescent exercise behavior

INTRODUCTION

Early motor development has been found to be a predictor of exercise behavior in children and adolescents, but whether this reflects a causal effect or confounding by genetic or shared environmental factors remains to be established.

METHODS

For 20,911 complete twin pairs from the Netherlands Twin Register a motor development score was obtained from maternal reports on the timing of five motor milestones. During a 12-year follow-up, subsamples of the mothers reported on the twins' ability to perform seven gross motor skills ability (N = 17,189 pairs), and weekly minutes of total metabolic equivalents of task (MET) spent on sports and exercise activities at age 7 (N = 3632 pairs), age 10 (N = 3735 pairs), age 12 (N = 7043 pairs), and age 14 (N = 3990 pairs). Multivariate phenotypic and genetic regression analyses were used to establish the predictive strength of the two motor development traits for future exercise behavior, the contribution of genetic and shared environmental factors to the variance in all traits, and the contribution of familial confounding to the phenotypic prediction.

RESULTS

Significant heritability (h2) and shared environmental (c2) effects were found for early motor development in boys and girls (h2 = 43-65%; c2 = 16-48%). For exercise behavior, genetic influences increased with age (boys: h2age7 = 22% to h2age14 = 51%; girls: h2age7 = 3% to h2age14 = 18%) paired to a parallel decrease in the influence of the shared environment (boys: c2age7 = 68% to c2age14 = 19%; girls: c2age7 = 80% to c2age14 = 48%). Early motor development explained 4.3% (p < 0.001) of the variance in future exercise behavior in boys but only 1.9% (p < 0.001) in girls. If the effect in boys was due to a causal effect of motor development on exercise behavior, all of the factors influencing motor development would, through the causal chain, also influence future exercise behavior. Instead, only the genetic parts of the regression of exercise behavior on motor development were significant. Shared and unique environmental parts of the regression were largely non-significant, which is at odds with the causal hypothesis.

CONCLUSION

No support was found for a direct causal effect in the association between rapid early motor development on future exercise behavior. In boys, early motor development appears to be an expression of the same genetic factors that underlie the heritability of childhood and early adolescent exercise behavior.

Between Dysbiosis, Maternal Immune Activation and Autism: Is There a Common Pathway?

Autism spectrum disorder (ASD) is a neuropsychiatric condition characterized by impaired social interactions and repetitive stereotyped behaviors. Growing evidence highlights an important role of the gut-brain-microbiome axis in the pathogenesis of ASD. Research indicates an abnormal composition of the gut microbiome and the potential involvement of bacterial molecules in neuroinflammation and brain development disruptions. Concurrently, attention is directed towards the role of short-chain fatty acids (SCFAs) and impaired intestinal tightness. This comprehensive review emphasizes the potential impact of maternal gut microbiota changes on the development of autism in children, especially considering maternal immune activation (MIA). The following paper evaluates the impact of the birth route on the colonization of the child with bacteria in the first weeks of life. Furthermore, it explores the role of pro-inflammatory cytokines, such as IL-6 and IL-17a and mother's obesity as potentially environmental factors of ASD. The purpose of this review is to advance our understanding of ASD pathogenesis, while also searching for the positive implications of the latest therapies, such as probiotics, prebiotics or fecal microbiota transplantation, targeting the gut microbiota and reducing inflammation. This review aims to provide valuable insights that could instruct future studies and treatments for individuals affected by ASD.

Developmental milestones in early childhood and genetic liability to neurodevelopmental disorders

BACKGROUND

Timing of developmental milestones, such as age at first walking, is associated with later diagnoses of neurodevelopmental disorders. However, its relationship to genetic risk for neurodevelopmental disorders in the general population is unknown. Here, we investigate associations between attainment of early-life language and motor development milestones and genetic liability to autism, attention deficit hyperactivity disorder (ADHD), and schizophrenia.

METHODS

We use data from a genotyped sub-set (N = 25699) of children in the Norwegian Mother, Father and Child Cohort Study (MoBa). We calculate polygenic scores (PGS) for autism, ADHD, and schizophrenia and predict maternal reports of children's age at first walking, first words, and first sentences, motor delays (18 months), and language delays and a generalised measure of concerns about development (3 years). We use linear and probit regression models in a multi-group framework to test for sex differences.

RESULTS

We found that ADHD PGS were associated with earlier walking age (β = -0.033, padj < 0.001) in both males and females. Additionally, autism PGS were associated with later walking (β = 0.039, padj = 0.006) in females only. No robust associations were observed for schizophrenia PGS or between any neurodevelopmental PGS and measures of language developmental milestone attainment.

CONCLUSIONS

Genetic liabilities for neurodevelopmental disorders show some specific associations with the age at which children first walk unsupported. Associations are small but robust and, in the case of autism PGS, differentiated by sex. These findings suggest that early-life motor developmental milestone attainment is associated with genetic liability to ADHD and autism in the general population.

The Effect of a Parent-Directed Program to Improve Infants' Motor Skills

Poor motor skills are associated with several factors that might delay children's development. Therefore, early programs to promote a child's motor development are essential. Within the first year of life, parents have a critical role in promoting their infant's motor development. However, little research has explored parent-directed programs that promote infant development in a Scandinavian context. This study aimed to evaluate the effectiveness of a parent-directed program to improve infant motor development.

METHODS

Parents of infants received a parent-directed program that included guidance from health visitors on ways to promote motor development, videos with motor development activities and a bag with related materials. Two municipalities in Denmark took part in the study (one intervention, one control). Health visitors in both municipalities measured the infants' age-appropriate motor skills once when the infants were between 9-11 months of age. A logistic regression model was used to analyze the data.

RESULTS

No difference was detected in motor development over time in the two municipalities regarding the proportion of children with age-appropriate motor skills.

CONCLUSIONS

A parent-directed program in which parents were guided to play and encourage motor development with their infant showed no effect on infants' age-appropriate motor skills at 9-11 months.

Interventions by Caregivers to Promote Motor Development in Young Children, the Caregivers' Attitudes and Benefits Hereof: A Scoping Review

In the first year of life, the child's caregivers, including parents and daycare staff, play an essential role, as they are responsible for implementing daily activities to promote the motor development of young children. However, what does the research show about interventions to promote the motor development of 0-36-month-olds carried out by the child's caregivers, and what are the caregivers' experiences and attitudes hereof? This scoping review aims to provide an overview of the published studies to derive an overall interpretation. A systematic search was conducted in five scientific databases, resulting in 10,219 articles, of which 9 met the inclusion criteria. The results indicate that providing early intervention to 0-36-month-old children, in which the caregivers carry out the activities, promotes the young child's motor development. Furthermore, the interventions increase the caregivers' interest and motivation to promote the young child's motor development, which is essential in maintaining the behaviour after the end of the interventions. Supervision and guidance provided for the child's caregivers concerning knowledge and skills about age-appropriate behaviours and facilitation of their child's motor development increases the caregivers' self-confidence, interest, and motivation.

Heritability of Psychological Traits and Developmental Milestones in Infancy: A Systematic Review and Meta-analysis

Importance

Although infancy is the most rapid period of postnatal growth and development, factors associated with variation in infant traits are not well understood.

Objective

To synthesize the large twin study literature partitioning phenotypic variance in psychological traits and developmental milestones in infancy into estimates of heritability and shared and nonshared environment.

Data Sources

PubMed, PsycINFO, and references of included publications were searched up to February 11, 2021.

Study Selection

Peer-reviewed publications using the classical twin design to study psychological traits and developmental milestones from birth to 2 years old were included.

Data Extraction and Synthesis

Data were extracted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and categorized using the International Classification of Functioning, Disability and Health: Children and Youth Version. Data were pooled in 3-level random effects models, incorporating within-cohort variance in outcome measurement and between-cohort variance. Data were analyzed from March 2021 through September 2021.

Main Outcomes and Measures

The primary outcomes were monozygotic and dizygotic twin correlations. These were used to calculate genetic and shared and nonshared environment estimates.

Results

Among 139 publications that were systematically retrieved, data were available on 79 044 twin pairs (31 053 monozygotic and 47 991 dizygotic pairs), 52 independent samples, and 21 countries. Meta-analyses were conducted on psychological traits and developmental milestones from 106 publications organized into 10 categories of functioning, disability, and health. Moderate to high genetic estimates for 8 categories were found, the highest of which was psychomotor functions (pooled h2, 0.59; 95% CI, 0.25-0.79; P < .001). Several categories of traits had substantial shared environment estimates, the highest being mental functions of language (pooled c2, 0.59; 95% CI, 0.24-0.86; P = .001). All examined categories of traits had moderate or high nonshared environment estimates, the highest of which were emotional functions (pooled e2, 0.42; 95% CI, 0.33-0.50; P < .001) and family relationships (pooled e2, 0.42; 95% CI, 0.30-0.55; P < .001).

Conclusions and Relevance

These findings may be an important source of information to guide future gene discovery research, public perspectives on nature and nurture, and clinical insights into the degree to which family history and environments may estimate major domains of infant functioning, disability, and health in psychological traits and developmental milestones.

Validity and Reliability of the Baby and Child Eating Behavior Questionnaire, Toddler Version (BEBQ-Mex and CEBQ-T-Mex) in a Low Sociodemographic Sample Recruited in a Mexican Hospital

The objective of this study was to validate and measure the internal reliability of the Baby and Child Eating Behavior Questionnaires for Toddlers (BEBQ-Mex and CEBQ-T-Mex), that evaluate appetitive trait (ATs). Mothers recruited from a public hospital in Guadalajara, Mexico, completed the BEBQ-Mex or CEBQ-T-Mex along with information on sociodemographic characteristics. Internal reliability of the BEBQ-Mex was sufficient for Food Responsiveness (FR) (Cronbach α = 0.82), while Enjoyment of Food (EF) and Satiety Responsiveness (SR) showed poor reliability (α = 0.56) and Slowness in Eating (SE) had unacceptable reliability (a = 0.36). All reliability values for the CEBQ-T-Mex were acceptable (>0.70), except for SE (α = 0.64). Confirmatory factor analysis (CFA) revealed an adequate model fit for the BEBQ-Mex, except the SE subscale. CFA for the CEBQ-T-Mex confirmed the six-factor structure. Mothers of a low sociodemographic background were unable to recognize their infants' ATs; the BEBQ-Mex partly met the criteria for validity and reliability. Mothers from similar sociodemographic characteristics were more able to recognize the ATs of their toddlers than their infants; the CEBQ-T-Mex was found to be a valid and reliable tool. Findings support the need to help mothers' ability to recognize their infants' ATs, which have been previously associated with weight and growth.

A novel de novo CAPN5 mutation in a patient with inflammatory vitreoretinopathy, hearing loss, and developmental delay

Mutations that activate the protease calpain-5 (CAPN5) cause a nonsyndromic adult-onset autoinflammatory eye disease characterized by uveitis, altered synaptic signaling, retinal degeneration, neovascularization, and intraocular fibrosis. We describe a pediatric patient with severe inflammatory vitreoretinopathy accompanied by hearing loss and developmental delay associated with a novel, de novo CAPN5 missense mutation (c.865C>T, p.Arg289Trp) that shows greater hyperactivation of the calpain protease, indicating a genotype–phenotype correlation that links mutation severity to proteolytic activity and the possibility of earlier onset syndromic disease with auditory and neurological abnormalities.