genes: the dopamine transporter (DAT1, locus symbol SLC6A3); dopamine D4 receptor (DRD4); dopamine D2 receptor (DRD2); serotonin transporter (5HTT, locus symbol SLC6A4); serotonin 2A receptor (5-HT2A); Monoamine Oxidase A promoter (MAOA-uVNTR); Monoamine Oxidase A STR (MAOA[GT]n); dopamine D5 receptor (DRD5); Catechol O-methyltransferase (COMT) val158met SNP (rs4680); and Insulin-like Growth Factor I (IGF1). Although genotype data are continually being generated, the following polymorphisms are currently available in the full Add Health sample: The dopamine transporter 40 base pair (bp) Variable Number Tandem Repeat (VNTR) in the 3′ untranslated region of the gene (DAT1; Vandenbergh et al. 1992);The 48 bp VNTR in the third exon of the dopamine D4 receptor gene (DRD4; van Tol et al., 1992);The 43 bp (not 44 bp as originally reported) addition/deletion in the 5′ regulatory region of the serotonin transporter gene (5HTTLPR; Heils et al.1996);SNP rs25531 in the Long form of the 5HTTLPR (Hu et al, 2005);The 30 bp VNTR in the promoter region of the monoamine oxidase A gene (MAOA; Samochowiec et al., 1999).
