山东汉族人群63个Y-STR基因座突变观察及法医学应用

Mutations at 63 Y-STR Loci in Shandong Han Population and the Forensic Applicability

目的调查分析山东汉族人群63个Y-STR基因座的突变情况,并评价其法医学应用价值。方法收集山东汉族人群1020对父子共2040份男性血样,采用自行设计引物,对63个Y-STR基因座进行复合扩增和毛细管电泳检测,统计各基因座的突变情况。对DYS481基因座使用Power Plex Y23引物与自行设计引物分别扩增,进行分型一致性检验。结果 1020对父子在其中53个基因座上共检出244次等位基因突变,平均突变率为3.8×10^(-3)(95%CI 3.3×10^(-3)~4.3×10^(-3)),其中突变率最高的DYS713为18.6×10^(-3)(95%CI 11.3×10^(-3)~28.9×10^(-3)),突变率最低的DYS438等10个基因座为0.98×10^(-3)(95%CI 0~5.5×10^(-3)),绝大多数突变为一步突变(91.8%),符合逐步突变的遗传规律,等位基因增加突变与等位基因减少突变比接近1:1。1020对父子中有214对父子在53个基因座上共观察到244次突变,其中一步突变224次,二步突变9次,三步突变2次,其他突变类型9次;176对父子仅1个基因座发生突变。使用两套引物,DYS481基因座在1020对父子中有1018对得到一致的分型结果,一致性为99.8%。结论本文63个Y-STR基因座中的高突变基因座在近亲个体识别时有一定作用,但在Y-STR数据库家系查询与父系鉴定应用中应予以注意。进行同一认定及亲缘鉴定时,同一案件应使用相同的引物序列。

Objective To investigate the mutations at 63 Y-STR loci in Shandong Han population and evaluate their forensic applicability. Methods Bloodstain samples of 1020 father-son pairs in Shandong Han population were DNA- typed by conducting YI and YII PCR multiplex amplification with a five-color fluorescence labeling 35 and 29 Y-STR loci. The mutations were calculated and the typing accuracy was checked by comparing the typing result of DYS481 from PowerPlexY23 primers with that of the designed primers. Results Among the 1020 father-son pairs, 244 mutations were detected from 53 genetic loci of 63 ones, the average mutation rate was 3.8×10^-3 （95 % CI 3.3×10^3-4.3×10^3） per locus. The highest mutation rate at DYS713 was 18.6×10^-3 （95% CI 11.3~103-28.9~103）, the lowest mutation rate often loci was 0.98× 10^-3 （95 % CI 0~5.5× 10^3）, and the vast majority of mutations was one-step mutation （91.8 %）, in consistency with the gradual mutation of the genetic law, and the allele increase or decrease from the mutation was 1：1. 224 mutations were one- step event, 9 mutations were the two-step＇s, 2 mutations were three-step＇s, other mutations occurred 9 times. The mutations in 176 father-son pairs happened at single locus. 1018 pairs of 1020 father-son pairs got the consistent results using two sets of primers in DYS481 loci, the consistency was 99.8 %. Conclusion The loci of high mutation rate is effective for the individual identification but should be cautious when the Y-STR database searching and patrilineal identification are recruited. During the parentage determination and individual identification, the same primers should be used for the same case.