二联体亲权鉴定风险分析

目的探讨二联体亲权鉴定时存在的风险。方法选取22组经Goldeneye~(TM) 20A试剂盒检测后只有一个或没有不符合基因座的无关个体对构建假想家系。对其增加检测STRtyper-10G和/或AGCU 21+1 STR系统直至所有组不符合基因座个数大于3个,累积父权指数(CPI)不大于0.000 1。以三种规则:(1)不符合基因座数大于3个;(2)CPI值小于0.000 1;(3)同时满足(1)和(2),作为排除依据,使用不同数量的基因座(19个、26个、39个和46个)进行检测,讨论无关个体对的排除情况是否存在差异。结果 22组无关个体对,使用19个基因座和39个基因座以上的检测系统达到排除结果的分别为0组和22组。结论二联体亲子鉴定,使用19个基因座进行检测仍存在结果错判,39个基因座以上的检测系统能更有效的避免二联体的鉴定风险。

Risk analysis on duo paternity tests

Objective To discuss the risk in duo paternity testing. Methods 22 fictitious duo families formed by 22 pairs of unrelated individuals having one or zero inconsistent locus were selected after detected by GoldeneyeTM 20A Kit. The 22 fictitious duo families were further tested with STRtyper-10G kit and/or AGCU 21+1 STR kit until there were more than 3 inconsistent loci and the cumulative paternity index(CPI) value was less than 0.0001. According to the three excluding rules, ① number of inconsistent loci>3; ② CPI ≤ 0.0001; ③ accord with both ① and ② , using multiple STR systems, such as 19 STR loci, 26 STR loci, 39 STR loci and 46 STR loci to test and discuss whether there is difference among the excluding result of unrelated individual. Results Among those 22 fictitious duo families, using three excluding rules, None was excluded by 19 STR loci, and all was excluded by 39 STR loci. Conclusion Duo paternity tests may get a wrong result using only 19 loci system. To reduce the error risk 39 STR-loci systems would be suggested.