The dopamine transporter SLC6A3 gene, also known as DAT1, has been studied in various mental disorders.
A well-studied variation found in the 3' region of the DAT is a 40 bp variable number tandem repeat (VTNR). This VNTR ranges from 3 to 11 copies with the 9-repeat (9R or 440 bp) and 10-repeat (10R or 480 bp) polymorphisms being the two most common alleles. [PMID 7557351] This repeat is not currently represented in SNPedia due to its absence in dbSNP; however, it is represented in OMIM (see 126455.0001).
In 250 alcohol-dependent Caucasian subjects: Of the 24% who exhibited withdrawal seizures, 4 SNPs were associated with presence and severity of the seizures: DAT1-VNTR, rs27072, rs27048, and rs2963238. [PMID 18070248]
Rs464049 has been associated with mood disorders.