Genetic variation dopamine transporter gene (SLC6A3) is associated with multiple neuropsychiatric disorders. Two tandem repeats that are GC rich were identified. These sequences can form G-Quadruplexes (G4s), which can interfere with normal genomic function. QGRS Mapper software predicted that these tandem repeats could form G4s, which was confirmed with circular dichroism (CD) spectroscopy. This finding could have implications for gene expression, splicing, or disease phenotypes, but studies must be done to confirm their role.