Moreover, there is a significant difference in the distribution of associated SNP markers between patients with ADHD and controls (Gao et al., 2015), and SNAP-25 gene MnlI polymorphisms are associated with the severity of ADHD symptoms (Bidwell et al., 2017; González-Giraldo and Forero, 2020). Here, SNAP25 is linked to attention deficit-hyperactivity disorder.