The dopamine receptor D4 gene (DRD4) contains a variable number tandem repeat (VNTR) polymorphism in exon III that has been associated with differences in attention regulation and impulsivity-related traits. Variation in repeat number, particularly the 4-repeat and 7-repeat alleles, has been proposed to influence dopaminergic signaling and may contribute to individual behavioral variability. Attention-related traits in adults are often measured using self-report screening instruments such as the Adult ADHD Self-Report Scale (ASRS). While these tools are widely used to assess behavioral tendencies, the extent to which self-reported measures correspond with underlying genetic variation remains an open question.
This study aims to characterize the distribution of DRD4 VNTR alleles within an undergraduate population and to explore potential relationships between VNTR genotype and ASRS scores. Saliva samples were collected from consenting participants, and genomic DNA extracted and amplified using PCR targeting the VNTR region. Amplicons were analyzed via gel electrophoresis to determine repeat number. Participants also completed the ASRS to generate standardized self-reported attention-related scores, which will be analyzed alongside genotypic data to examine potential patterns of association.
Genomic DNA isolation, PCR primers, and conditions were optimized for reliable amplification of the VNTR region. Interpretation of the results of this ongoing study will be adjusted accordingly, depending on the sample size of the study population. By integrating molecular genotyping with behavioral self-report data, this project seeks to contribute to ongoing discussions about the complex relationship between genetic variation and measurable behavioral traits.