Having a specific regional focus is important in examination of methylation of CpG sites across OXTR because methylation patterns for this gene have been shown to be multi-dimensional, with several factors accounting for variation in methylation across the gene (e.g., Cecil, et al., 2015; Kim et al, 2014; Simons et al., in press). Based on the prior data, we hypothesized that we would identify a set of CpGs that loaded together on a single factor representing physically contiguous loci located on or around the end of the first exon of OXTR, suggesting strong potential for regulatory impact. Prior research has identified a set of three loci on the first exon that are both stress responsive and associated with social/affiliative schemas in adults (see Simons, et al., in press), making them an ideal candidate set.
