PRIMA1 and Borderline personality disorder: Methylation studies of the ribosomal RNA gene (rDNA) promoter, 5′ external transcribed spacer gene (5′ETS) and of the proline rich membrane anchor 1 gene (PRIMA1) promoter in PBC DNA of female subjects with BPD (n = 24) and HC (n = 11) revealed significantly less methylation of the rDNA promoter region in BPD compared with HC subjects, and hypomethylation of the 5′ETS in BPD by trend.