STR polymorphisms of "forensic loci" in the northern Han Chinese population

A preliminary Chinese DNA database has been constructed by the analysis of samples from 2,211 Han Chinese in Liaoyang City, northeast China. Thirteen autosomal tetranucleotide short tandem repeats (STRs) widely used in forensic identification were selected for the DNA profiling, together with the X-Y homologous gene Amelogenin for sex determination. Only one of the 13 autosomal loci showed significant deviation from Hardy-Weinberg equilibrium in the individuals genotyped. The cumulative discrimination power and power of exclusion of the 13 loci were greater than 0.999999999 and 0.9999888, respectively, giving an average match probability of 5.5×10-15 for the population. Allelic distributions at the vWA, TH01, D13S317, and D16S539 loci differed from African-Americans and US Caucasians, and more detailed population data at these four loci may be needed to ensure their applicability for forensic purposes in Chinese populations. Previously unreported alleles were detected at several loci (some at relatively high frequencies), suggesting the need for their inclusion in the reference allelic ladder to meet the practical standard of forensic profiling in certain Chinese ethnic sub-populations. The preliminary DNA database provides base-line information applicable to the construction of a National Index System for criminal DNA profiling in PR China.