Exploring the relationship between OXTR DNA methylation and temperament in children with neurodevelopmental disabilities

Introduction: ) has been associated with socioemotional functioning and individual differences in temperament, yet its role in children with neurodevelopmental disabilities (NDs) remains underexplored. Methods: DNAm across 13 CpG sites within intron 1 in a sample of 24 children with NDs and 24 typically developing (TD) children aged 3-36 months. DNAm was assessed from buccal epithelial cells collected via salivary swabs. To account for intercorrelations among CpG sites, principal component analysis (PCA) was applied, yielding two components (PC1: 7 CpGs; PC2: 6 CpGs). Temperament was assessed through parent-report measures of Surgency/Extraversion, Negative Emotionality, and Effortful Control. Analyses controlled for age and developmental quotient (DQ). Results: DNAm in children with NDs compared to TD children, specifically in PC2. Higher DNAm in PC2 was associated with lower Surgency/Extraversion in children with NDs, but not in TD children. No significant associations emerged for Negative Emotionality or Effortful Control. Conclusion: DNAm may represent a potential epigenetic correlate of early socio-emotional development in this population.