Tuesday, August 07, 2007

ADHD & DRD4   posted by Razib @ 8/07/2007 10:45:00 AM

Polymorphisms of the Dopamine D4 Receptor, Clinical Outcome, and Cortical Structure in Attention-Deficit/Hyperactivity Disorder:
Possession of the DRD4 7-repeat allele was associated with a thinner right orbitofrontal/inferior prefrontal and posterior parietal cortex. This overlapped with regions that were generally thinner in subjects with ADHD compared with controls. Participants with ADHD carrying the DRD4 7-repeat allele had a better clinical outcome and a distinct trajectory of cortical development. This group showed normalization of the right parietal cortical region, a pattern that we have previously linked with better clinical outcome. By contrast, there were no significant effects of the DRD1 or DAT1 polymorphisms on clinical outcome or cortical development.

A correlation between the 7-repeat allele, which exhibits variation in frequency between populations, and ADHD is interesting and important. But it is nice to get some more functional specificity to clarify the chain of causation responsible for the correlation we see.

Related: In Our Genes.