Two genome-wide significant findings (corrected for single analysis) emerged from the formal tests, one for rs6565113 in an intron of CDH13 associated under an additive genetic model with the FBAT-PC-based phenotype derived from all ADHD symptoms, one for rs552655 in an intron of GFOD1 associated with the FBAT-PC phenotype for inattentive symptoms (dominant model). The CDH13 finding is especially interesting, since a SNP near this gene also is part of the top-25 in the GWAS by Neale et al. (2008a, b), though the two studies are not entirely independent, of course, and the gene is also found among the top-findings from the ADHD GWAS by Lesch et al. (2008, see below) and falls into the only significant ADHD linkage region identified in the recent meta-analysis (Zhou et al. 2008c). Furthermore, association with SNPs in CDH13 is one of the most consistent findings in genome-wide studies on a wide variety of phenotypes related to drug abuse and dependence (Uhl et al. 2008a, b), although there is no clear indication, which region of the gene is most important. Possibly, different regions or
