Fig. 1: Nucleotide sequences of repeat units and the genetic architecture of 5-HTTLPR alleles.

A Names, genetic architecture, and allele frequencies of 5-HTTLPR alleles identified in this study. The allele names refer to the comprehensive summary of 5-HTTLPR alleles⁶, and individual repeat units are identified by the Greek-letter nomenclature introduced by Nakamura et al⁵. Novel alleles are underlined. The total number of alleles and their allele frequencies (%) are given. CCSS: case-control study set, ACSS: Arao cohort study set. B Structure of repeat units. Each repeat unit is assigned a Greek letter following the nomenclature of Nakamura et al. The nucleotide sequence of ζ is shown in bold. Nucleotide substitutions are highlighted in light gray, and insertions are in dark gray compared to ζ. Dark boxes in novel repeat units indicate nucleotide substitutions or insertions compared to the original repeat units. C Representative 5-HTTLPR genotypes in agarose gel electrophoresis. The lengths of the PCR amplicons are as follows: S_14-A, 457 bp; S_15-E, 479 bp; L_16-A, 499 bp; L_16-D, 499 bp; XL_19-A, 567 bp; XL_20-A, 583 bp; XL_22-A, 625 bp; and XL_28-A, 751 bp.