GAD1 and schizophrenia: PRS mice showed a marked and long-lasting increase in DNMT enzymes (both 1 and 3a), and TET enzymes and a significant increase in 5-methylcytosine (5MC) and 5-hydroxymethylcytosine (5HMC) in the promoters of putative schizophrenia-related genes, such as bdnf , gad1, reln, and the early inducible gene, GADD45 (growth arrest DNA demage), associated with an alteration in these gene expression.