As a further measure, all large CNVs identified in the ADHD group were additionally tested with custom Agilent Human Genome comparative genomic hybridisation (CGH) 44K microarrays (CA, USA) enriched for probes at each of the loci harbouring a CNV larger than 500 kb. This procedure was done at Oxford Gene Technologies (Oxford, UK) in accordance with standard protocols. CGH analysis failed for two samples, each carrying one CNV. Of the 57 rare CNVs larger than 500 kb with high-quality CGH data, only two were not validated. Of the controls, 940 (carrying 71 of the 78 CNVs identified) had previously undergone independent CNV analysis with Affymetrix 250K NspI and StyI arrays (CA, USA).11 68 of the 71 rare CNVs larger than 500 kb that we identified in these samples were also identified by the Affymetrix platform.11 To be conservative, we excluded the two CNVs in the ADHD group that were not confirmed by high-quality data on the second platform (leaving a total of 57), whereas we included all 78 CNVs in the control group including those that were not confirmed by
