The Genomics Center of the AMMS, Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, PR China.
The Genomics Center of the AMMS, Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, PR China.
Forensic Sci Int Genet. 2020 May;46:102265. doi: 10.1016/j.fsigen.2020.102265. Epub 2020 Feb 25.
Individual commercially available kits exhibit limited discrimination power in full-sibling and second-degree kinship analysis, and therefore they are commonly combined with other kits to obtain more loci and a higher efficacy. However, few studies have systematically evaluated the discrimination power of combined loci. In this study, we combined the ForenSeq™ DNA Signature kit (containing 27 short tandem repeats [STRs] + 91 single nucleotide polymorphisms [SNPs]) with the AGCU NC 21 + 1 PCR amplification kit (containing 21 STRs) to obtain a non-overlapping set of 40 STR and 91 SNP markers. The discrimination power was evaluated for 74 full-sibling pairs, 114 uncle/aunt-nephew/niece pairs and 93 grandparent-grandson/granddaughter pairs. The results show that the efficacy of the 40 STR + 91 SNP combination is higher than the efficacy of either 27 STRs + 91 SNPs or 40 STRs alone. Both the sensitivity and specificity of the 40 STR + 91 SNP marker set achieved 100 % in full-sibling testing, with strong power to distinguish second-degree relatives from unrelated pairs. The 40 STR + 91 SNP set could also distinguish most full-sibling relatives from second-degree relatives but was insufficient to distinguish relatives who belong to the same autosomal kinship class. Our results suggest that ignoring linkage can lead to incorrect likelihood ratios for both related and unrelated pairs, while mutation had a relatively lower effect on the likelihood ratios. Moreover, linkage and mutation had a higher impact on full-sibling testing than on second-degree kinship testing. The discrimination power of the 40 STR and 91 SNP marker set could be strengthened by adding an additional relative.
个体市售试剂盒在全同胞和二级亲属分析中的鉴别能力有限，因此通常与其他试剂盒结合使用，以获得更多的基因座和更高的效率。然而，很少有研究系统地评估了组合基因座的鉴别能力。在这项研究中，我们将 ForenSeq™ DNA Signature 试剂盒（包含 27 个短串联重复序列 [STRs] + 91 个单核苷酸多态性 [SNP]）与 AGCU NC 21 + 1 PCR 扩增试剂盒（包含 21 个 STRs）结合使用，获得了一组非重叠的 40 个 STR 和 91 个 SNP 标记。我们评估了 74 对全同胞、114 对叔/伯/姑/舅/侄/侄女和 93 对祖父/祖母-孙/孙女/外孙/外孙女的鉴别能力。结果表明，40 个 STR + 91 个 SNP 组合的效率高于 27 个 STRs + 91 SNPs 或 40 个 STRs 单独使用的效率。40 个 STR + 91 SNP 标记组合在全同胞检测中的灵敏度和特异性均达到 100%，具有较强的能力来区分二级亲属与无关个体。40 个 STR + 91 SNP 组合也可以区分大多数全同胞亲属与二级亲属，但不足以区分属于同一常染色体亲缘关系类别的亲属。我们的结果表明，忽略连锁可能导致相关和无关个体的似然比错误，而突变对似然比的影响相对较小。此外，连锁和突变对全同胞检测的影响大于对二级亲属检测的影响。通过添加一个额外的亲属，可以增强 40 个 STR 和 91 个 SNP 标记组合的鉴别能力。
