Sunday, August 31, 2008

ADHD gene #1 (DRD4)

The ADHD genes

ADHD treatment options

On my last post on ADHD treatment options I listed 7 different genes that have been found to be affiliated with ADHD. We will be focusing on the first listed ADHD gene in this post, the Dopamine D4 receptor gene (DRD4).

ADHD Gene #1: Dopamine D4 receptor gene (DRD4): exon III VNTR, 7-repeat

* A quick note: The"exon III VNTR, 7-repeat" bit listed above is a type of nomenclature used by geneticists to describe where on the gene the "ADHD allele" is found. Since genes can be fairly long (the "average" gene for humans is thought to be over 10,000 blocks of DNA strung together), this nomenclature is used to pinpoint both the location and what type of DNA the "ADHD form" of this gene contains. Genetic screeners will look to see if this form is present to assess your "genetic risk" for ADHD. For those of you who are interested or are familiar with genetics, I will include this information for these 7 ADHD genes, otherwise, feel free to ignore this extra info!

This gene is located on the 11th chromosome of the human genome. It is perhaps the gene most commonly affiliated with ADHD, and some studies suggest that the "ADHD allele" mentioned above is tied to nearly doubling the likelihood of an individual having ADHD. Based on research up to this point, the DRD4 gene has, potentially, the strongest correlation to ADHD for the aforementioned ADHD genes. This gene is highly associated with the frontal region of the brain (frontal subcortex), and is more affiliated with the inattentive component of ADHD than the hyperactive one, which suggests that this gene may be more tied to ADD than most of the other 6 ADHD genes listed previously.

ADHD genes and treatments