X染色体四个STR基因座的遗传多态性及法医学意义

目的 建立X染色体短串联重复序列DXS7133、GATA198A10、DXS9896、DXS6797基因座的复合扩增系统，调查成都汉族人群的遗传多态性并探讨其法医学应用价值。方法 应用PCR和非变性聚丙烯酰胺凝胶电泳分型技术，并检验各基因座女性基因型频率分布是否符合hardy-Weinberg平衡，计算法医学常用各种概率。结果 DXS7133、GATA198A10、DXS9896、DXS6797基因座在成都地区汉族群体中(男100，女120)分别发现6、6、11、8个等位基因，女性个人识别几率分别达0．7962、0．8021、0．9675和0．9444。X^2检验表明各基因座女性的基因型频率分布符合Hardy-Weinherg平衡。32个亲子鉴定案例调查表明这4个基因座符合X染色体伴性遗传方式，未发现突变。结论 DXS7133、GATA198A10、DXS9896、DXS6797基因座在成都汉族群体中具有较高的遗传多态性，适用于个人识别和女孩的亲权鉴定。

Genetic polymorphisms of four STR loci on chromosome X and their forensic applications in a Chinese Han population

Objective To add DXS7133, GATA198A10, DXS9896 and DXS6797 to the panel of forensically validated X chromosome markers, and apply the multiplex amplification system to a population study and forensic analysis on the Hans of Chengdu. Methods The PCR products were detected by the polyacrylamide gel electrophoresis and silver staining method. Hardy-Weinberg equilibrium of females was tested and every forensically interested value was calculated. Results Sequencing revealed that their common sequence motifs were tetranucleotide repeats. Population genetic data were obtained by analyzing 120 unrelated females and 100 males from Chengdu Han ethnic group. In this population, DXS7133, GATA198A10, DXS9896 and DXS6797 exhibited 6, 6, 11, 8 distinguishable alleles respectively. Chi-square test demonstrated that genotype frequencies in females did not depart from Hardy-Weinberg equilibrium. Power of discrimination for female samples for the four loci were 0.7962, 0.8021, 0.9675, and 0.9444. The parentage testing in 32 cases revealed a typical X-linked inheritance and no mutations. Conclusion DXS7133, GATA198A10, DXS9896 and DXS6797, which are highly polymorphic in Chengdu Han population, are appropriate for individual identification and paternity testing involving a female child.