Transporter Gene Linked to Attention-Deficit Disorder
Polymorphism near norepinephrine gene correlates with lower expression
TUESDAY, Dec. 5 (HealthDay News) -- A variation of the norepinephrine transporter gene is strongly associated with attention-deficit/hyperactivity disorder (ADHD), according to study findings published online Dec. 4 in the Proceedings of the National Academy of Sciences Early Edition.
Kwang-Soo Kim, Ph.D., of Harvard Medical School and McLean Hospital in Belmont, Mass., and colleagues studied a previously uncharacterized A/T polymorphism known to occur upstream of the norepinephrine transporter gene (SLC6A2) start site. They genotyped 94 ADHD patients and 60 healthy controls.
The investigators found that the T allele was much weaker at driving expression of a reporter gene because it becomes a binding site for transcriptional repressor proteins found in neurons. These repressors, called Slug and Scratch, were shown to bind specifically to the T allele. The A/T polymorphism in the SLC6A2 gene was twice as common in patients than controls.
"We observed a significant association between the [T allele] and ADHD, suggesting that anomalous transcription factor-based repression of SLC6A2 may increase risk for the development of ADHD and other neuropsychiatric diseases," the authors conclude.