Comparisons between Japanese and Han Chinese populations for 261 autosomal STR loci

In this study, Japanese and Han Chinese individuals (n = 32, each) were genotyped for 261 autosomal STRs, and allele frequencies were calculated for each locus in each population. The average number of alleles for all loci in Japanese and Han Chinese populations was 6.65 and 6.56, respectively. The tests for deviations from HWE performed using an exact test showed that the number of STRs (P > 0.05) in Japanese and Han Chinese populations was 236 and 241, respectively. Calculation of forensic parameters showed heterozygosity, and the exclusion means in the Japanese population were 0.7185 and 4813 and those in the Han Chinese population were 0.7308 and 0.5008. In addition, population genetic analyses, such as principal component analysis and factorial correspondence analysis, were performed and a differential formula with likelihood ratios was applied for various number of STR loci based on the effectiveness of differentiation between the two populations. Accordingly, this study suggests that statistical differentiation between genetically close populations, such as the Japanese and Han Chinese populations, is possible if approximately 40–50 effective STR loci are analyzed.