YC_ACTIONBB2

This is the Biochemical Study of the ACTION project (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and interventION strategies Consortium; http://www.action-euproject.eu/). The aim of the biochemical study was to further validate the biomarker assays and metabolomics platforms selected during the technical pilot in a larger twin sample. The twins were selected based on their mother-rated aggression scores (Achenbach System of Empirically Based Assessment (ASEBA) Child Behavior Checklist) at age 3 and/or 7. The Biochemical study comprised concordant low-scoring twin pairs, concordant high-scoring twin pairs, and a discordant low-high scoring twin pairs. High aggression was defined as having an ASEBA CBCL Aggression Syndrome Scale T-score equal to or larger than 65, and low aggression as an ASEBA CBCL Aggression Syndrome Scale T-score of less than 65. Here, data collection comprised of first-morning urine samples and buccal-cell DNA samples in the twins and family members living at the same address as the participating twin pairs were also asked to provide a buccal-cell DNA sample. During the urine and buccal-cell collection, parents of the twins were asked to complete the ASEBA CBCL for school-aged children (6-18 years) to reflect the current child behaviors, and to provide information about health condition of the twins and conditions of urine collection. Biochemical measurement in urine included a dipstick, density (specific gravity), creatinine, neopterin, C-peptide, Substance P, oxidized DNA/RNA, procalcitonin, total antioxidant capacity, and glucose, and two metabolomics platforms: 1) a liquid chromatography mass spectrometry (LC-MS) platform targeting amines; and 2) a LC-MS platform targeting steroid hormones. Buccal-cell samples genotyped on the Affymetrix Axiom genotyping array.