SLC6A3 and neurodevelopmental disorder: Certain single nucleotide polymorphisms (SNPs) of dopamine-related genes (e.g., dopamine receptor 2 [DRD2] and DRD3 for DA release, dopamine transporter [DAT] for DA clearance, monoamine oxidase A [MAOA] and catechol-O-methyltransferase [COMT] for DA degradation) have been associated with neurodevelopmental disorders in children.