In cortical Brodmann's area 10 (BA10) and peripheral blood lymphocytes of Schizophrenia patients, DNMT1 and to a lesser extent DNMT3a, mRNAs were reported to be upregulated [24].The increased expression of S-adenosyl methionine and DNA methyltransferase-1 has been postulated to contribute to promoter cytosine 5-methylation and to downregulation of the expression of mRNAs encoding for reelin and GAD67 in cortical GABAergic neurons of schizophrenia and bipolar disorder patients [25]. Here, DNMT3A is linked to bipolar disorder.