SON and attention deficit-hyperactivity disorder: On a locus-specific level, the ADHD PGS was associated with differential methylation in an epigenome-wide significant level with two genes that were not implicated in ADHD or other psychiatric disorders by GWASs yet (GART—phosphoribosylglycinamide formyltransferase, phosphoribosylglycinamide synthetase, phosphoribosylaminoimidazole synthetase, and SON—DNA and RNA binding protein) [147].