亲子鉴定中STR位点数选择及其应用价值研究

Evaluation on the number and value of STR loci applied in paternity identification

目的对在亲子鉴定中STR位点数的选择及其鉴定应用价值进行研究。方法将CODIS13个STR位点分为四个观测组,观测对象包括排除亲权的母亲-孩子-假设父亲三人组合102例,以及肯定亲权的母亲-孩子-假设父亲三人组合100例,通过310遗传分析仪对荧光复合扩增产物进行分型检测。结果各STR观察组出现的最低排除指标数与各观察组累积非父排除概率(CPE)值成一定正相关性,CPE值超过99.99%的两个STR观察组其出现的最低排除指标数为三个,同时这两个STR观察组在肯定亲权的案例分析中,其亲子关系概率值(RCP)值都超过了99.99%。结论对于亲子鉴定中的STR位点检测系统,其非父排除指标应为三个以上,其累积非父排除概率(CPE)值达到99.99%时,就可以认为该STR位点检测系统具有了相关的鉴定应用价值。

Objective The study was carried out on the evaluation of number and value of STR loci applied in paternity identification. Methods A total of 13 STR loci, divided into four groups, was observed in 102 cases of paternity exclusion and 100 cases of paternity inclusion. PCR amplified products of 13 STR loci were injected into a capillary on the ABI PRISM 310 Genetic Analyzer. GeneScan software analyzed the collected data, which can then be imported into Genotyper software for genotyping of alleles. Results At least 3 STR loci incompatibilities between alleged father and child were found in all paternity exclusion cases of two observed groups which Cumulative Probability of Exclusion (CPE) was more than 99.99%, and in all paternity inclusion cases of those same observed groups, their Relative Chance of Paternity(RCP) could be over 99.99%.Conclusion The exclusion of paternity should be based on at least three STR loci incompatibilities in the identification practice. As a criterion for evaluation of the number and value of STR loci applied in paternity test,CPE should reach 99.99%.