Analysis of the polymorphic structure of short tandem repeats locus D18S555

We analyzed the polymorphic structure of the short tandem repeats (STR) (RRGG) locus D18S555 by DNA sequencing, and examined the distribution of alleles in DNA samples from Japanese and Chinese individuals. DNA sequence analysis showed that the alleles at this locus consisted of deletions or insertions of (gaaagaaagaat), (ggaa), (ggaaggaaggag), (ggaaggagggaaggaaggag), (gggaggaa), and (ggga) 5, with each allele having its own DNA sequence. Analysis of 200 unrelated Japanese and 169 unrelated Chinese subjects identified 11 alleles, of which alleles 4, 6, and 13 occurred with a high frequency. There was no difference in allele frequency between the two ethnic groups. These results indicate that the genotyping of D18S555 alleles requires no sequence analysis, and making the locus applicable to forensic identity.