Small duplications and deletions on 15q13.3 have been found to be associated with neuropsychiatric phenotypes that include ADHD. Recurrent deletions of chromosome 15q13.3 are associated with developmental delay and a variety of neuropsychiatric phenotypes. It has been suggested that haploinsufficiency of CHRNA7 may have a causal role (38). Duplications spanning CHRNA7 have also been found to be associated with a broad range of neuropsychiatric phenotypes that include ADHD (39, 40). Increased dosage of CHRNA7 in these microduplications has been considered to be responsible.
