To determine if chmp7+/− fish have reduced chmp7 mRNA, thereby mimicking the reduction observed in individuals homozygous for the ADHD risk allele (T) of the ADHD-associated SNP, quantitative real-time PCR (qRT-PCR) on cDNA from chmp7+/+, chmp7+/−, and chmp7−/− 6 dpf fish was performed. The gene discussed is CHMP7; the disease is attention deficit-hyperactivity disorder.