All ADHD-risk alleles of the four risk variants identified in males significantly decreased (t < 0) the KTN1 mRNA expression consistently across the frontal and occipital cortices, limbic system (hippocampus and thalamus), BG (nucleus accumbens and substantia nigra) and cerebellum (1.2 × 10–5 ≤ p ≤ 0.039; Tables 2, 3, 4, 5, 6, 7, 8, 9, 10), with rs10132888 demonstrating the most significant regulatory effect on mRNA expression in the nucleus accumbens (p = 1.2 × 10–5; Table 2). The gene discussed is KTN1; the disease is attention deficit-hyperactivity disorder.