Forensic characterisation and polymorphism analysis of 16 X-chromosomal STRs in the Jining Han population in Eastern China

X-chromosomal short tandem repeats (X-STRs) are a useful supplementary approach to analysing autosomal markers in forensics and kinship studies; such markers are not well-characterised in many populations.
To investigate population genetic polymorphism and forensic characterisation of 16 X-STRs in the Jining Han population, and analyse genetic relationships with other Chinese populations.
Allele frequencies for 16 X-STR loci were obtained from a sample set of 527 unrelated individuals from the Jining Han population. Population genetic analyses of Jining Han and another 10 reference populations were conducted using phylogenetic tree, principal component analysis and multidimensional scaling.
We detected 149 alleles, with frequencies ranging from 0.0013 to 0.8242. The combined powers of discrimination in males and females were 0.999999997194774 and 0.999999999999995, respectively. The combined mean exclusion change (MEC)Krüger, MECKishida, MECDesmarais, and MECDesmarais Duos values were 0.999974632649096, 0.999999976997582, 0.999999977013201, and 0.999993755768423, respectively. We detected relatively high genetic homogeneity in populations with similar ethnic or geographic origins, and a close relationship between the Jining Han and Beijing Han populations.
The present findings indicate that the 16 X-STR loci examined are highly polymorphic in the Han population of Jining, providing useful information for forensic science and population genetics studies.

X染色体短串联重复序列（X-chromosomal short tandem repeats, X-STRs）是法医学与亲缘关系研究中分析常染色体标记的有效补充手段，但目前多数人群中这类标记的特征化研究仍不够充分。
本研究旨在探究济宁汉族人群中16个X-STR基因座的群体遗传多态性与法医学特征，并分析其与其他中国人群的遗传亲缘关系。
本研究从济宁汉族人群的527名无关个体样本中，获取了16个X-STR基因座的等位基因频率数据。采用系统发育树、主成分分析以及多维标度法，对济宁汉族人群及另外10个参考人群开展群体遗传学分析。
本研究共检出149个等位基因，频率范围为0.0013至0.8242。男性与女性的联合个人识别能力分别为0.999999997194774与0.999999999999995。累积平均排除概率（mean exclusion change, MEC）方面，Krüger法MEC、Kishida法MEC、Desmarais法MEC以及Desmarais Duos法MEC的数值分别为0.999974632649096、0.999999976997582、0.999999977013201及0.999993755768423。研究发现，种族或地理起源相近的人群具有较高的遗传同质性，济宁汉族人群与北京汉族人群亲缘关系密切。
本研究结果表明，本次检测的16个X-STR基因座在济宁汉族人群中具有高度遗传多态性，可为法医学及群体遗传学研究提供有价值的参考信息。