Journal Article

Attention Deficit/Hyperactivity Disorder Children with a 7-Repeat Allele of the Dopamine Receptor D4 Gene Have Extreme Behavior but Normal Performance on Critical Neuropsychological Tests of Attention

Schuck, Sabrina, Spence, M. Anne, Whalen, Carol K., Wasdell, Michael, Carlson, Caryn, Ding, Yuanchun, Posner, Michael I., Kennedy, James L., Moyzis, Robert, Chi, Han-Chang, Chen, Chuansheng, Mann, Miranda, Babb, Kimberley A., Sergeant, Joseph A., Swanson, James, Murias, Michael, Oosterlaan, Jaap, Flodman, Pamela, Zhang, Ya-Ping, Sadeh, Avi, Smith, Moyra, Leung, Patrick

2000

Overview

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

• Publisher: National Academy of Sciences of the United States of America,National Acad Sciences,The National Academy of Sciences
• Subject: Alleles / Attention / Attention Deficit Disorder with Hyperactivity - genetics / Attention Deficit Disorder with Hyperactivity - psychology / Attention deficit hyperactivity disorder / Biological Sciences / Child / chromosome 11 / Chromosome Mapping / Chromosomes, Human, Pair 11 / Cohort Studies / Control groups / Disorders / Dopamine receptors / DRD4 gene / Etiology / Exons / Female / Genotypes / Humans / Male / Minisatellite Repeats / Neuropsychological Tests / Receptors, Dopamine D2 - genetics / Receptors, Dopamine D4 / Reference Values / Stimulants / Symptoms