NKX2-2 and attention deficit-hyperactivity disorder: Each of these LD blocks harbours genes that have previously been linked to either ASD or ADHD risk at the genome-wide or suggestive level17,21, or, potentially, involve single-variant co-localisation37: chromosome 1p21.3 (1,734 kb: PTBP217, PTBPLP, 7SK, DPYD37, DPYD-AS137), chromosome 5q14.3 (1,500 kb: TMEM161B21, TMEM161B-AS121, LINC0046121, MIR9-221, MEF2C21, AL050132) and chromosome 20p11.22-23 (1524 kb: PLK1S1(KIZ)17, BC042893, BC034426, XRN217, NKX2-2, NKX2-417, Nkx2_2as, PAX137, LOC100270679, CR627206, LOC284788) (Supplementary Fig. 4).