@article{Neale2010, abstract = {Objective: Although twin and family studies have shown attention-deficit/hyperactivity disorder (ADHD) to be highly heritable, genetic variants influencing the trait at a genome-wide significant level have yet to be identified. As prior genome-wide association studies (GWAS) have not yielded significant results, we conducted a meta-analysis of existing studies to boost statistical power. Method: We used data from four projects: a) the Children's Hospital of Philadelphia (CHOP); b) phase I of the International Multicenter ADHD Genetics project (IMAGE); c) phase II of IMAGE (IMAGE II); and d) the Pfizer-funded study from the University of California, Los Angeles, Washington University, and Massachusetts General Hospital (PUWMa). The final sample size consisted of 2,064 trios, 896 cases, and 2,455 controls. For each study, we imputed HapMap single nucleotide polymorphisms, computed association test statistics and transformed them to z-scores, and then combined weighted z-scores in a meta-analysis. Results: No genome-wide significant associations were found, although an analysis of candidate genes suggests that they may be involved in the disorder. Conclusions: Given that ADHD is a highly heritable disorder, our negative results suggest that the effects of common ADHD risk variants must, individually, be very small or that other types of variants, e.g., rare ones, account for much of the disorder's heritability. J. Am. Acad. Child Adolesc. Psychiatry, 2010;49(9):884-897.}, author = {Neale, Benjamin M. and Medland, Sarah E. and Ripke, Stephan and Asherson, Philip and Franke, Barbara and Lesch, Klaus-Peter and Schaefer, Helmut and Faraone, Stephen V. and Nguyen, Thuy Trang and Daly, Mark and Steinhausen, Hans-Christoph and Schäfer, Helmut and Freitag, Christine and Holmans, Peter and Reif, Andreas and Renner, Tobias J. and Walitza, Susanne and Romanos, Marcel and Romanos, Jasmin and Warnke, Andreas and Meyer, Jobst and Palmason, Haukur and Vasquez, Alejandro Arias and Buitelaar, Jan K. and Lambregts-Rommelse, Nanda N. J. and Gill, Michael and Anney, Richard Jl L. and Williams, Nigel and Langely, Kate and O'Donovan, Michael and Thapar, Anita and Owen, Michael and Sergeant, Joseph and Kent, Lindsey and Roeyers, Herbert and O’Donovan, Michael and Mick, Eric and Smalley, Susan and Biederman, Joseph and Doyle, Alysa and J. A., Sergeant and Loo, Sandra and Todorov, Alexandre and Hakonarson, Hakon and Elia, Josephine and Miranda, Ana and Mulas, Fernando and Ebstein, Richard P. and Rothenberger, Aribert and Sonuga-Barke, Edmund J. S. and Banaschewski, Tobias and Oades, Robert D. and Barke, Edmund and McGough, James and Nisenbaum, Laura and Middleton, Frank and Hu, Xiaolan and Nelson, Stan}, doi = {10.1016/j.jaac.2010.06.008}, journal = {Journal of the American Academy of Child and Adolescent Psychiatry}, month = {aug}, pages = {884-897}, title = {Meta-analysis of genome-wide association studies of attention deficit/hyperactivity disorder}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2928252}, volume = {49}, year = {2010} }