Patterns of DNA methylation at specific loci of the dopamine transporter 1 gene and psychopathological risk in trios of mothers, fathers and children

While accumulating literature is demonstrating the role of the dopamine transporter (DAT) in predicting emotional–behavioural difficulties in adults of at risk populations, only few studies have focused on the possible association between the methylation status of the DAT promoter and the psychopathological risk of mothers, fathers and children in normative samples. The pattern of methylation of M1-M7 loci present in the 5′-untranslated promoter region (5′-UTR) of DAT1, and parental and offspring psychopathological risk were assessed in a sample of 152 families with 5-year-old-children, employing principal components (PCAs) and cluster analyses. Parents’ psychopathological symptoms were assessed through SCL-90/R; children’s emotional-behavioural functioning was evaluated through C-TRF. Cluster analysis allowed to form three clusters; cluster 1 is primarily composed by children with low-/middle-risk profiles; most of children with high-risk are in this cluster, and had parents with mild/high psychopathological risk; children in cluster 2 showed low-risk profiles and their parents had low/mild psychopathological risk; children in cluster 3 were predominantly at middle risk and had parents with low psychopathological risk. Analysis of results shows that DNA methylation occurs in different loci of DAT1 according to patterns of psychopathology and that psychopathological risk is specifically associated with hyper-methylation or hypo-methylation of these loci.