FHIT and attention deficit-hyperactivity disorder: GWAS analysis conducted by Lasky-Su et al. found genes (KChIP1 [alias name KCNIP1], KChIP4 [alias name KCNIP4], dipeptidyl-peptidase 10 [DPP10], and fragile histidine triad protein [FHIT]) related to potassium-channel function associated with total ADHD symptom count [12].