Global DNA hypomethylation and its correlation to the betaine level in peripheral blood of patients with schizophrenia

In this study, we identified decrease of global DNA methylation level in FESZ (N = 24 patients vs N = 42 controls), and found that global DNA methylation level was inversely correlated with scores on the global assessment of functioning (GAF) scale, and positively correlated with plasma betaine level. Notably, correlations between levels of betaine and its metabolites (N,N-dimethylglycine and sarcosine, N-methylglycine) were lower or lost in FESZ plasma, but remained high in controls. We further examined LINE-1 DNA methylation levels in patients with chronic SZ (N = 388) and BD (N = 414) as well as controls (N = 430), and confirmed significant hypomethylation and decreased betaine level in SZ. We also found that patients with BD type I, but not those with BD type II, showed significant global hypomethylation. These results suggest that global hypomethylation associated with decreased betaine level in blood cells is common to SZ and BD, and may reflect common pathophysiology such as psychotic symptoms.
Source: Progress in Neuro Psychopharmacology and Biological Psychiatry - Category: Psychiatry Source Type: research