Altered DNA methylation of the AluY subfamily in schizophrenia and bipolar disorder

Aim: To study DNA methylation patterns of AluY subfamilies in schizophrenia (SCZ) and bipolar disorder (BPD). Patients & methods: A bisulfite conversion-specific one-label extension method was employed to detect the AluY subfamily methylation levels of peripheral blood DNA from 92 SCZ patients, 99 BPD patients and 92 controls. Results: Hypermethylation of the AluY A1 and A2 CpG sites in BPD patients and hypomethylation of A3 CpG site in both of BPD and SCZ patients, and opposite age-dependent methylation alterations between SCZ and controls. Conclusion: The differentially altered DNA methylation patterns of the AluY families between BPD and SCZ suggest the role of DNA methylation in the pathogenesis of these major psychiatric disorders.