Whereas none of the investigated polymorphisms have been associated with tinnitus (using a group without tinnitus as controls), a variant in the promoter of the serotonin transporter gene (SLC6A4) (OMIM 182138) was associated with tinnitus severity when compared with patients with milder tinnitus.46 Similarly, a pilot genome-wide association study25 with a small sample size of 167 patients and 769 controls found no significant associations but revealed an enrichment in genes involved in serotonin receptor signaling. Here, SLC6A4 is linked to Tinnitus.