Yang Da, Ma Sheng Xuan, Zhao Guo Liang, Gao Ao, Xu Zhao Kun
Institute of Forensic Medicine And Laboratory Medicine, Jining Medical University, Shandong province, P. R. China; Forensic Science Center of Jining Medical University, Shandong province, P. R. China.
Institute of Forensic Medicine And Laboratory Medicine, Jining Medical University, Shandong province, P. R. China.
Leg Med (Tokyo). 2024 Jul;69:102441. doi: 10.1016/j.legalmed.2024.102441. Epub 2024 Apr 4.
The pedigree likelihood ratio (LR) can be used for determining kinship in the forensic kinship testing. LR can be obtained by analyzing the DNA data of Short tandem repeat (STR) and single nucleotide polymorphism (SNP) loci. With the advancement of biotechnology, increasing number of genetic markers have been identified, thereby expanding the pedigree range of kinship testing. Moreover, some of the loci are physically closer to each other and genetic linkage between loci is inevitable. LRs can be calculated by accounting for linkage or ignoring linkage (LR and LR, respectively). GeneVisa is a software for kinship testing (www.genevisa.net) and adopts the Lander-Green algorithm to deal with genetic linkage. Herein, we used the simulation program of the software GeneVisa to investigate the effects of genetic linkage on 1st-degree, 2nd-degree, and 3rd-degree kinship testing. We used this software to simulate LR and LR values based on 43 STRs and 134 SNPs in commercial kits by using the allele frequency rate and genetic distance data of the European population. The effects of linkage on LR distribution and LRs of routine cases were investigated by comparing the LR values with the LR values. Our results revealed that the linkage effect on LR distributions is small, but the effect on LRs of routine cases may be large. Moreover, the results indicated that the discriminatory power of genetic markers for kinship testing can be improved by accounting for linkage.
系谱似然比（LR）可用于法医亲缘关系鉴定中确定亲属关系。通过分析短串联重复序列（STR）和单核苷酸多态性（SNP）位点的DNA数据可获得LR。随着生物技术的进步，已鉴定出越来越多的遗传标记，从而扩大了亲缘关系鉴定的系谱范围。此外，一些位点在物理上彼此更接近，位点之间的遗传连锁是不可避免的。可以通过考虑连锁或忽略连锁（分别为LR和LR）来计算LR。GeneVisa是一款用于亲缘关系鉴定的软件（www.genevisa.net），采用兰德-格林算法处理遗传连锁。在此，我们使用软件GeneVisa的模拟程序来研究遗传连锁对一级、二级和三级亲缘关系鉴定的影响。我们利用该软件，根据欧洲人群的等位基因频率和遗传距离数据，基于商业试剂盒中的43个STR和134个SNP模拟LR和LR值。通过比较LR值和LR值，研究连锁对常规案例的LR分布和LR的影响。我们的结果表明，连锁对LR分布的影响较小，但对常规案例的LR影响可能较大。此外，结果表明，通过考虑连锁可以提高亲缘关系鉴定中遗传标记的鉴别能力。
