Yukta Kulkarni ’22
Attention deficit hyperactivity disorder (ADHD) is a common disorder prevalent in both children and adults with symptoms such as inattention, hyperactivity, and impulsiveness. The identification of certain genes associated with ADHD can improve both the understanding of the neural mechanisms that transpire and the ability to accurately diagnose and treat people with ADHD. By researching and integrating data from various research publications, Harich et al. strived to identify and define ADHD-associated genes.
The researchers utilized 11 different publications, each performing their own unique copy number variation study. This type of study notes the number of copies of a specific gene the participants have since this can vary from person-to-person. In total, there were about 6,000 participants who had ADHD and 25,000 participants who acted as a control (did not have the ADHD genes). The researchers looked up genes associated with ADHD symptoms (attention deficit, hyperactivity, and impulsivity) on the Monarch Initiative database. Since there are numerous genes associated with ADHD, they selected and prioritized a few genes based on recurrence in ADHD individuals and absence in the control subjects, specifically by gene copy number, the number of copies of a gene seen in an individual. For example, if two genes have overlapping copy number variation, the narrowed-down overlap was used instead of two separate genes. Furthermore, only genes that code for mRNAs (messenger-RNAs) were selected for further analysis.
Through their selective categorization process, 432 genes were labeled as high-ranking ADHD genes. Of those, 66 genes were associated with ADHD symptoms in the cross-species database. Overall, 26 genes were commonly observed over all of the bioinformatic methods, with POLR3C and RBFOX1 being common genetic variants. With increased filtering of genes and determining which ones are associated with certain disorders, it can help identify those who have or are at risk for the disorder. For instance, if a person is expressing the labeled ADHD genes, it can be an indicator that they are either experiencing symptoms, have ADHD, or have a related mental disorder. However, future research will need to provide a deeper understanding of ADHD before labeled genes can aid in the development of new treatments or diagnostic tools.
 B. Harich, From rare copy number variants to biological processes in ADHD. The American Journal of Psychiatry 177, 855-866 (2020). Doi: https://doi.org/10.1176/appi.ajp.2020.19090923
 Image retrieved from: https://pixabay.com/illustrations/man-dna-spiral-biology-merge-2125123/