D3S1358等9个STR基因座在同胞鉴定中的应用

Application of 9 STR loci in siblings identification

目的探讨D3S1358等9个常染色体STR基因座用于鉴定两个体间同胞亲缘关系的可行性。方法用复合PCR扩增方法检测D3S1358等9个STR基因座的基因型,运用ITO法和IBS法两种分析方法计算两个体间的同胞亲权关系指数(paternity index,PI)和同胞亲权关系概率RCP(relativechance of paternity,RCP),并比较两个体间全相同、半相同和全不同的基因座数。结果同胞个体间RCP值均值显著高于非同胞个体(P>0.05)。同胞对全相同的基因座个数平均值>3,全不同的基因座个数平均值<2;而无关个体间全相同的基因座个数平均值<1,全不同的基因座个数平均值>3。结论检测和分析D3S1358等9个STR基因座的基因型可以应用于同胞鉴定:以RCP≥95%或者以基因型全相同基因座数≥4或全不同基因座数≤1为肯定标准;以RCP≤5%或者以基因型全相同基因座数=0或全不同基因座数≥4为排除标准。

Objective To investigate the probability of siblings testing by the 9 autosomal STR loci such as D3S1358. Methods These 9 STR loci were amplified by multiplex PCR, and then the genotypes were detected by ABI 310 genetic analyzer. The paternity index （PI） and the relative chance of paternity （RCP） were calculated according as the ITO and IBS methods. And the allelic matching of the STR loci was compared between the sib-pairs group and the random individuals group. Results The RCP value of the sibpairs group was higher than that of the random individuals group. In the sib-pairs group, the average number of the entirely same loci was more than 3, and the average number of the entirely different loci was less than 2. But in the random individuals group, the average number of the entire same loci was less than 1, and the average number of the entirely different loci was more than 3. Conclusion The results suggest that it is effective to identify siblings by analyzing the genotypes of these 9 STR loci such as D3S1358.