A recent meta-analysis of candidate gene association studies of childhood ADHD estimated the pooled association with 38 polymorphisms (29 SNPs) in 18 genes. 17 Twenty of the 29 SNPs were genotyped for the current study and only one was significant at p<0.05 in single SNP tests (rs6280 in DRD3, p=0.018). Neither of the significant SNPs from the meta-analysis and included in our study were statistically significant (rs27072 p=0.7; rs3746544 p=0.9), and none of the genes (SLC6A3, DRD4, DRD5, SLC6A4, HTR1B, CHRNA4 and SNAP25) implicated by statistically significant association with markers not available in our sample were statistically significant in gene-based set-tests (Table S1, available online).
