DNA Methylation of Regulatory Regions of Imprinted Genes at Birth and Its Relation to Infant Temperament

BACKGROUND: DNA methylation of the differentially methylated regions (DMRs) of imprinted genes is relevant to neurodevelopment. METHODS: DNA methylation status of the DMRs of nine imprinted genes in umbilical cord blood leukocytes was analyzed in relation to infant behaviors and temperament (n = 158). RESULTS: MEG3 DMR levels were positively associated with internalizing (beta = 0.15, P = 0.044) and surgency (beta = 0.19, P = 0.018) behaviors, after adjusting for birth weight, gender, gestational age at birth, maternal age at delivery, race/ethnicity, education level, smoking status, parity, and a history of anxiety or depression. Higher methylation levels at the intergenic MEG3-IG methylation regions were associated with surgency (beta = 0.28, P = 0.0003) and PEG3 was positively related to externalizing (beta = 0.20, P = 0.01) and negative affectivity (beta = 0.18, P = 0.02). CONCLUSION: While the small sample size limits inference, these pilot data support gene-specific associations between epigenetic differences in regulatory regions of imprinted domains at birth and later infant temperament.