A study of the possible association between adenosine A2A receptor gene polymorphisms and attention-deficit hyperactivity disorder traits

Abstract

The adenosine A2A receptor (ADORA2A) is linked to the dopamine neurotransmitter system and is also implicated in the regulation of alertness, suggesting a potential association with attention-deficit hyperactivity disorder (ADHD) traits. Furthermore, animal studies suggest that the ADORA2A may influence ADHD-like behavior. For that reason, the ADORA2A gene emerges as a promising candidate for studying the etiology of ADHD traits. The aim of this study was to examine the relationship between ADORA2A gene polymorphisms and ADHD traits in a large population-based sample. This study was based on the Child and Adolescent Twin Study in Sweden (CATSS), and included 1747 twins. Attention-deficit hyperactivity disorder traits were assessed through parental reports, and samples of DNA were collected. Associations between six single nucleotide polymorphisms (SNPs) and ADHD traits were examined, and results suggested a nominal association between ADHD traits and three of these SNPs: rs3761422, rs5751876 and rs35320474. For one of the SNPs, rs35320474, results remained significant after correction for multiple comparisons. These results indicate the possibility that the ADORA2A gene may be involved in ADHD traits. However, more studies replicating the present results are warranted before this association can be confirmed. When examining the relationship between adenosine A2A receptor (ADORA2A) gene polymorphisms and ADHD traits in a population-based sample of 1747 twins, results showed nominal associations between ADHD traits and three SNPs in the ADORA2A gene: rs3761422, rs5751876 and rs35320474. For one of the SNPs, rs35320474, results remained significant after correction for multiple comparisons. These results indicate the possible involvement of the ADORA2A in ADHD traits, a plausible notion as adenosine plays a role in ADHD-related neurobiological mechanisms such as dopamine neurotransmission and regulation of alertness. However, these results should be viewed as preliminary and more studies replicating the present results are warranted before this association can be confirmed. © 2013 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society.