Cytosine methylation in GABA B1 receptor identifies alcohol-related changes for men in blood and brain tissues.

This article investigates sex-dependent epigenetic changes in the promoter methylation of the GABBR1 gene, which encodes the GABA_B receptor subunit 1, in relation to alcohol use disorder (AUD). Using post-mortem brain tissue from six addiction-related regions and blood samples of 17 individuals with AUD and 31 controls, the study found significant hypomethylation at a specific CpG site (CpG −4) in male AUD subjects across multiple brain regions, notably the amygdala and mammillary bodies, with similar but non-significant trends in blood. No consistent methylation changes were observed in female AUD subjects. These findings suggest sex-specific epigenetic regulation of GABBR1 in AUD and highlight CpG −4 hypomethylation as a potential biomarker for male AUD, warranting further research into its clinical applicability and underlying mechanisms.