Association of childhood chronic physical aggression with a DNA methylation signature in adult human T cells

Chronic physical aggression (CPA) is characterized by frequent use of physical aggression from early childhood to adolescence. Observed in approximately 5% of males, it is associated with early childhood adverse environments. DNA methylation, a covalent modification of DNA, regulates genome function and has been associated with early childhood adverse environments. We analyzed T cell DNA genome-wide promoter methylation profiles from two groups of adult males assessed annually for frequency of physical aggression between 6 and 15 years of age: a group with CPA and a control group. Whole genome methylation analysis was performed using MeDIP followed by hybridization to microarrays. We mapped the promoter regions of 20 000 genes and 400 microRNAs. The subjects were recruited from participants in two longitudinal studies of child development9,47. We recruited two groups of Caucasian males who were born in families with a low socioeconomic status and were living at the time of the present study within 200km from our laboratory. The first group had a history of high physical aggression from age 6 to 15 years (chronic physical aggression group, CPA). The second group was recruited from the same longitudinal studies but included only those who did not have a history of high physical aggression from age 6 to 15 (Control group). A total of 65 eligible subjects agreed to participate (8 CPA and 57 controls). Using custom-designed microarrays with 244K probes tiling the promoter regions of 20000 genes and 400 microRNAs, we obtained DNA methylation profiles by meDIP-chip. Each profile was generated in triplicate.