546例亲子鉴定案件中基因突变的观察和分析

目的:在亲权鉴定案件中经常可以观察到突变,突变会直接影响到亲权指数(PI)的计算。这里我们观察分析15个STR基因座在山西汉族人群亲子鉴定案件中的突变特点和规律。方法:546例确认亲子关系案件来自于山西汉族人群,包括父-母-子三联体案件383例,二联体案件163例。用含15个STR基因座的Power Plex16 System kit试剂盒对上述案例进行分析。结果:在546例亲子鉴定案件中共有22例出现突变,Penta E,D5S818,D7S820,v WA,D21S11 5个位点均出现3例突变,突变率最高为0.32%;FGA,D8S1179 2个位点突变均为2例,突变率为0.22%;CSF1PO,D3S1358,D18S51 3个位点突变均为1例,突变率为0.11%;未观察到其余基因座的基因突变。22例突变全部为一步突变,其中来自父亲的突变10例,来自母亲7例,5例无法确定突变来源。22例突变中增加1个基序的10例,减少1个基序的10例,增加减少不明确的2例。结论:山西汉族人群常染色体STR的突变率在0%~0.32%之间,该数据为计算突变情况下的亲权指数提供了数据支持。

Observation and analysis of mutation on 546 parentage testing cases

Objective:Mutation is often observed and the mutation rate is important for the paternity index ( PI) calculation. Here we summarized the mutations of 15 STR loci in Chinese Han population from Shanxi Province,China. Methods:A total of 546 par-entage confirmed paternity cases from Shanxi Han population,including 383 triplets and 163 duos,were typed with PowerPlex ? 16 System kit. The mutation data were collected and analyzed. Results:Twenty two mutation events were observed. Among 15 STR loci, PentaE,D5S818,D7S820,vWA,D21S11 had the highest mutation rate of 0. 32%. The second place went to FGA,D8S1179 loci,in which 0. 22% mutation were found. One mutation event occurred in CSF1PO, D3S1358 and D18S51, respectively with the rate of 0. 11%. No mutation was observed in the rest of STRs. All the observed mutation events were single-step mutation. Ten of them came from the father,7 from the mother and 5 mutations could not be identified of the origin. 10 mutation alleles showed repeats gaining while 10 alleles showed one repeat loss. Conclusion:The mutation rates of autosome STR loci of Chinese Han population in Shanxi are be-tween 0 and 0. 32%. Our data may be helpful for evaluating the PI when mutation occurred.