GWAS for quantitative phenotypes (Lasky-Su et al. 2008b). The authors also tested potential G × E effects for the list of ADHD candidate genes defined earlier (Brookes et al. 2006). Interaction association P values are most significant for DDC (mother’s warmth and criticism), HTR2A and SLC9A9 (warmth) at 10−4.Table 5Summary of the GxE interaction association P values <10−5 using total ADHD symptoms as the phenotype (Sonuga-Barke et al. 2008)Environmental variableSNPGenetic modelMain genetic effect P valueInteraction effect estimateInteraction P valueSNP positionPositionGene functiona Additional remarksMother’s criticismrs2825388Recessive3.27E-051.067.82E-06chr21:19458520IntergenicSite known for CNVsrs2827093Additive3.37E-050.724.78E-06chr21:22142959IntergenicSite known for CNVsMother’s warmth rs2212361 Dominant6.96E-06−0.979.08E-07chr11:93951971In intron of PIWIL4Encodes piwi-like 4, a protein expressed in brain and other tissues. PIWIL4 plays an important role in the chromatin-modifying pathway in human somatic cells. rs2212361 Additive2.53E-050.695.78E-06chr11:93951971rs7126782Dominant2.12E-05−0.952.42E-06chr11:93963488 rs1792040 Dominant1.74E-050.992.33E-06chr13:28274943Within 60-120 kb of SLC46A3Encodes solute carrier family 46, member 3, a gene expressed in many tissues including brain. The substrate of the transporter is not known rs1792040 Additive1.75E-05−1.253.05E-06chr13:28274943 rs1161453 Additive2.26E-06−1.472.33E-06chr13:28315484 rs1161453 Dominant5.05E-050.825.53E-06chr13:28315484 rs1161463 Dominant3.18E-050.843.34E-06chr13:28329338 rs1161463 Additive1.20E-06−1.721.45E-06chr13:28329338 rs1161457 Additive8.34E-06−1.412.14E-06chr13:28332854 rs1161457 Dominant2.41E-050.952.75E-06chr13:28332854rs11752175Dominant1.17E-050.994.65E-06chr6:39625468Within intron of KIF6Encodes kinesin family member 6, a member of the superfamily of molecular motors that are involved in intracellular transport. Several kinesins have been implicated in the pathogenesis of chronic diseases, including neurodegenerative diseases, type 2
