The results revealed significant differential associations between two a priori loci and ADHD phenotypes, rs6296 in HTR1B with inattention and rs3746544 in SNAP-25 with hyperactivity-impulsivity.
Evidence for an association between the HTR1B gene and ADHD as a qualitative diagnosis, or the inattentive and hyperactive-impulsive quantitative traits was not supported by either TDT single marker analysis or haplotype analysis.