CHRNA7 and attention deficit-hyperactivity disorder: Among these, a ~134-kb region of overlap between nine heterozygous duplications and one heterozygous deletion, encompassing several exons in the 3′ region of CHRNA7 (cholinergic nicotinic receptor alpha 7, 15q13.3; Fig. 2), presented nominally significant association with PC1 in the CLDRC-RD subset (while no CNV calls were detected in CLDRC-ADHD).