NOTCH2 and attention deficit-hyperactivity disorder: The single-marker analysis showed nominal association between ADHD and four SNPs in three genes: rs1621 and rs6566 within the MET gene (P=8.3e−03, OR=1.23 (1.06−1.44) and P=0.017, OR=1.19 (1.03−1.39), respectively), rs699779 in the NOTCH2 gene (P=7.7e−03; OR=3.45 (1.28−9.09)) and rs1175982 in the HMGA2 gene (P=7.5e−03; OR=1.34 (1.08−1.67); Table 1b, Supplementary Figure 1).