The gene-based analysis revealed six genes in four loci (ST3GAL3, FRAT1/FRAT2, CGB1, and RNF225/ZNF584) significantly associated with persistent ADHD, with ST3GAL3 being the most significant one (P = 8.72E−07) (Table S2a). Here, FRAT2 is linked to attention deficit-hyperactivity disorder.