I have run moderation analysis to study the interaction between SNP (dominant model) of a gene (A) with DNA methylation on cognition measures. For this, I have calculated the mean DNA methylation levels at 3 gene loci: Upstream of TSS (transcriptional start site), promoter, and gene body.
The protein from this gene improves cognition so we expect that increasing serum protein leads to better cognition outcomes. Prior research suggests that methylation in the gene body generally results in increased gene expression.
The results of the analysis showed that: in the carriers of genotype TT, increasing methylation rate in the gene body results in less recognition ability while in the holders of the C allele, higher methylation in the gene body is associated with improved recognition (2 different directions).
I know that different alleles can impact methylation rate but here the direction is completely opposite. How can I interpret the result?