Genetic variations and forensic characteristics of Han Chinese population residing in the Pearl River Delta revealed by 23 autosomal STRs.

Pearl River Delta, known as the Chinese "South Gate", locates adjacent to Hong Kong and Macao, and across the sea from the Southeast Asian region. Herein, 4325 unrelated Han Chinese individuals residing in the Pearl River Delta region were recruited and genotyped with 23 autosomal STRs (the expanded CODIS core loci plus D6S1043, Penta D and Penta E). No evidence of deviation from Hardy-Weinberg equilibrium after Bonferroni correction was observed. The combined match probability and combined power of exclusion were 1.7829 × 10-28 and 0.9999999996, respectively. Next, population comparisons among ethnically, linguistically, and geographically diverse populations (11 Chinese populations based on genotypes of same 23 autosomal STRs, 46 Chinese nationwide populations based on allele frequency distributions of 19 autosomal STRs and 51 worldwide populations on the basis of 20 autosomal STRs) were performed via Structure, MDS, PCA and neighbor-joining tree. Genetic heterogeneities among Chinese nationalities along ethno-linguistic boundaries (Turkic-speaking, Tibeto-Burman-speaking, and Chinese-speaking populations) and geographic divisions (North-Han and South-Han) have been illustrated by first two autosomal microsatellite datasets. The results from worldwide population genetic relationship exploration based on 20 autosomal STRs demonstrated that genetic affinity has existed within ethnical and geographical close populations.