(A) Genotyping of VNTR located in exon 3 of DRD4. Lines 1 and2: Heterozygote 2/4, Lines 3, 5, 6: Heterozygote 4/7, Line 4: Homozygote 4/4, Line 7: 50 bp ladder. (B) Genotyping of VNTR located in the 3’UTR of SLC6A3. Line 1: Homozygote 9/9, Line 2: Heterozygote, Line 3: Homozygote 10/10, Line 4: 50 bp ladder. (C) Genotyping of TaqIA polymorphism in DBH. Lines 1 and 2: Heterozygote, Line 3: 50 bp ladder, Line 4: homozygote A1/A1, Line 5: homozygote A2/A2. (D) Genotyping of SNP rs6296 of HTR1B. Line 1: Homozygote C/C, Lines 2 and 3: Homozygote G/G, Line 4: 100 bp ladder, Line 5: Negative control, Line 6: Heterozygote. (E) Genotyping of the 44-bp insertion/deletion in SLC6A4. Lines 1 and 5: Heterozygote, Lines 2 and 3: Homozygote S/S, Line 6: Homozygote L/L.