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

Introduction Oxytocin plays a crucial role in socio-emotional development. DNA methylation (DNAm) of the oxytocin receptor gene ( OXTR ) has been associated with socioemotional functioning and individual differences in temperament, yet its role in children with neurodevelopmental disabilities (NDs) remains underexplored. Methods The present study examined OXTR 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 Results indicated higher OXTR 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 These findings provide preliminary and exploratory evidence of an association between OXTR DNAm and temperamental positive emotionality in children with NDs. OXTR DNAm may represent a potential epigenetic correlate of early socio-emotional development in this population.