Background: The early environment provides many cues to young organisms that guide their development as they mature. Maternal personality and behavior are an important aspect of the environment of the developing human infant. The molecular mechanisms by which these influences are exerted are not well understood. We attempted to identify whether maternal traits could be associated with alterations in DNA methylation patterns in infants.
Methods: 32 women oversampled for history of depression were recruited in pregnancy and provided information on depressive symptoms, attachment style, and history of early life adversity. Buccal cell DNA was obtained from their infants at six months of age for a large-scale analysis of methylation patterns across 5x106 individual CpG dinucleotides, using clustering-based criteria for significance to control for multiple comparisons. Separately, associations between maternal depression, attachment style, and history of adversity and psychobehavioral outcomes in preschool-age children were examined.
Results: Tens of thousands of individual infant CpGs were alternatively methylated in association with each of the three studied maternal traits. Genes implicated in cell-cell communication, developmental patterning, growth, immune function/inflammatory response, and neurotransmission were identified. The result sets were highly coextensive among the three maternal traits, but areas of divergence exhibited intriguing parallels with behavioral outcomes.