鲁西南地区汉族人群15个STR基因座的突变观察与分析

Mutation analysis of 15 STR loci in the Han population of southwest Shandong province

目的观察和分析15个常染色体STR基因座在鲁西南地区汉族人群亲子鉴定中的突变现象及规律。方法应用直接扩增法对15个常染色体STR基因座进行荧光标记复合扩增PCR,扩增产物用3500遗传分析仪电泳分离,Gene Mapper ID-X分析软件进行STR结果分型。并对2013-2015年受理的9326例亲子鉴定进行STR基因座突变规律的研究。结果 9326例亲子鉴定中共观察到77例突变,其中一步突变占97.4%,两步突变及三步突变各占1.3%。在15个STR基因座中除TH01和TPOX外均发生突变,突变频率介于0至0.0011,整体突变率为0.0006。父源性STR基因座突变率远远高于母源性突变(3∶1)。结论 STR基因座突变是一种较为常见的遗传现象,通过对突变案例的观察分析,能够为法医物证学亲子鉴定STR基因座的选择提供有效的理论支撑,避免突变对鉴定结论的干扰以保证鉴定结果的客观准确。

Objective To observe and analyze the mutation phenomenon of 15 STR loci in Han population of southwest Shandong province. Methods In this study,the samples were directly amplified without DNA extraction by PCR amplification kit according to the manufacture's protocol. The detection of PCR products and genotyping were carried out on the ABI 3500 Genetic Analyzerusing the ABI GeneMapperID-X data collection software. 15 STR loci were studied during 2013-2015 in 9,326 paternity testing cases in forensic science center of Jining Medical University.Results In the 9,326 cases,one step mutation cases were observed in which 97. 4% of the total 77 mutations occurred.Two steps and three steps mutations had been occurred,respectively. Among them no mutation was found at TH01 and TPOX loci. The locus-specific mutation rate ranged from 0 to 0. 0011,and the overall mutation rate estimation was 0.0006. The paternal mutation rate was more frequent than the maternal rate( 3∶ 1). Conclusion STR loci mutation is a common phenomenon. Our results provide useful information for further investigation on STR mutation in forensic genetics and population genetics,which ensures that the results are accurate and reliable.