Totally, 239 subjects were enrolled in this case-control study: 86 patients with RAS and 153 healthy individuals were genotyped for serotonin transporter length polymorphic region (5-HTTLPR) polymorphism, variable number tandem repeat (STin2) and single nucleotide polymorphisms (rs25531, rs3813034, rs1042173) in the SLC6A4 gene by polymerase chain reaction with/without restriction analysis.