Olivia Wootton | Search PubMed

PubMed2026

The contribution of common and rare genetic variation to emotional and behavioural symptoms in childhood and adolescence.

Genetic factors influence vulnerability to common mental health conditions, but their role in early-life mental health remains understudied. We analysed genotype array (n = 4709-6687) and exome sequence data (n = 4500-5424) from the Millennium Cohort Study (MCS) and Avon Longitudinal Study of Parents and Children (ALSPAC) to assess the contribution of common variants and rare deleterious coding variants to internalising and externalising symptoms across development. In longitudinal analysis spanning ages 5-17 years, we identified several associations between common genetic variation, indexed by polygenic indices (PGIs), and both symptom domains that generally remained stable across development. Effect sizes were modest, with the largest estimates observed for PGIs for attention deficit hyperactivity disorder (ADHD) and externalising behaviour with externalising symptoms (β = 0.13-0.18; p-adj<3.5×10⁻29). Evidence for direct genetic effects was strongest for externalising symptoms, including for associations with the ADHD and externalising behaviour PGIs. Concordant results were observed in the Born in Bradford cohort. A higher exome-wide burden of deleterious rare variants was associated with increased externalising and internalising symptoms (β = 0.04-0.06, p-adj<0.03); within-family models indicated direct genetic effects on externalising in MCS (β = 0.07; p < 0.05, p-adj>0.05) and on internalising symptoms in ALSPAC (β = 0.12, p-adj<0.02). Common and rare genetic variants contributed independently, jointly explaining 2% of the variance in internalising and 5-7% in externalising symptoms. This study shows that early-life mental health is influenced by both common and rare genetic variation, with several associations explained by direct genetic effects.

Journal Article↗

PubMed2025

Investigating the interplay between prematurity and genetic variation in the context of rare developmental disorders.

BACKGROUND: Rare damaging genetic variation accounts for a substantial proportion of the risk of rare developmental disorders (DDs), but common genetic variants as well as environmental factors, including prematurity, also contribute. Little is known about the interplay between prematurity and genetic variation in influencing phenotypic outcomes in DDs, nor about how genetic factors may contribute to risk of preterm birth in DDs. METHODS: We leveraged phenotypic and genetic data from 21,712 patients with DDs recruited for clinical sequencing, 16% of whom were born prematurely. Using multivariable regression models, we compared phenotypic features and the prevalence of diagnostic genetic variation in specific genes between preterm and term individuals with DDs. We tested whether the fraction of cases attributable to de novo mutations differed between term and preterm probands. Additionally, we assessed whether associations between common variant contributions to education-related traits and prematurity are explained by direct genetic effects. RESULTS: Prematurity was associated with more severe clinical phenotypes among these DD patients, including more affected organ systems and more delayed developmental milestones. Prematurity and the presence of a monogenic diagnosis contributed additively to severity. We found that genes associated with fetal anomalies were enriched for diagnostic mutations among preterm individuals (p = 7.83 × 10-5). We also demonstrated an exome-wide enrichment of de novo mutations (DNMs) in both term and preterm probands; the fraction of cases explained by DNMs in known DD-associated genes was higher in term than preterm cases (25% versus 20%) but DNMs in as-yet-undiscovered genes likely contribute approximately equally to both groups (14% versus 13%). Finally, we showed that the positive association between polygenic predisposition to education-related traits and gestational duration is likely to be the result of genetically influenced parental traits or confounders, rather than direct genetic effects in the child, and that a monogenic diagnosis modifies this association. CONCLUSIONS: Our findings emphasise the importance of considering environmental factors like prematurity in understanding outcomes in DDs suspected to have a genetic component, and motivate further exploration of the role that genetic variation plays in influencing prematurity.

Humans↗