Genome-wide analysis of copy number variants in attention deficit hyperactivity disorder: the role of rare variants and duplications at 15q13.3.

Abstract

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.Attention deficit hyperactivity disorder (ADHD) is a common, highly heritable psychiatric disorder. Because of its multifactorial etiology, however, identifying the genes involved has been difficult. The authors followed up on recent findings suggesting that rare copy number variants (CNVs) may be important for ADHD etiology. The authors performed a genome-wide analysis of large, rare CNVs (100 kb in size, which segregated into 912 independent loci. Overall, the rate of rare CNVs >100 kb was 1.15 times higher in ADHD case subjects relative to comparison subjects, with duplications spanning known genes showing a 1.2-fold enrichment. In accordance with a previous study, rare CNVs >500 kb showed the greatest enrichment (1.28-fold). CNVs identified in ADHD case subjects were significantly enriched for loci implicated in autism and in schizophrenia. Duplications spanning the CHRNA7 gene at chromosome 15q13.3 were associated with ADHD in single-locus analysis. This finding was consistently replicated in an additional 2,242 ADHD case subjects and 8,552 comparison subjects from four independent cohorts from the United Kingdom, the United States, and Canada. Presence of the duplication at 15q13.3 appeared to be associated with comorbid conduct disorder. These findings support the enrichment of large, rare CNVs in ADHD and implicate duplications at 15q13.3 as a novel risk factor for ADHD. With a frequency of 0.6% in the populations investigated and a relatively large effect size (odds ratio=2.22, 95% confidence interval=1.5–3.6), this locus could be an important contributor to ADHD etiology.Novartis Shire Eli Lilly Elminda Janssen McNeil Fundacion Areces (Spain) Fundacion Dr. Manuel Camelo A.C., Medice Pharmaceuticals Spanish Child Psychiatry Association Shionogi Pharma Cipher Pharmaceuticals Janssen-Cilag Vifor Alcobra NIH R13MH059126 R01MH62873 R01MH081803 Pfizer Guilford Press Oxford University Press Affymetrix Power Award Wellcome Trust, U.K. Action Medical Research UK Radboud University Nijmegen Medical Center Deutsche Forschungsgemeinschaft KFO 125 SFB 581 GRK 1156 ME 1923/5-1 ME 1923/5-3 GRK 1389 Bundesministerium fur Bildung und Forschung (BMBF 01GV0605 Health Research Board Irelan