Department of Forensic Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, Sichuan, China.
Int J Legal Med. 2010 Sep;124(5):457-8. doi: 10.1007/s00414-009-0381-4. Epub 2009 Oct 30.
During the course of paternity test, three samples in two cases were apparently homozygous at the CSF1PO locus using AmpFlSTRs Identifiler PCR Amplification kits, but using the PowerPlexs 16 kit, the three individuals were found to be heterozygous. This puzzling problem was solved by using multiple analytical approaches, including the use of different primer pairs and the characterization of the mutation causing the ''null allele.'' Dropout was caused by a single mutation event in the presumptive binding site of the forward primer. While the frequency of these silent alleles remains low (0.5% in our study), it is suggested that appropriate measures should be taken for database comparisons and that allelic dropout should be further investigated by sequence analysis and be reported to the forensic community.
在进行亲子鉴定的过程中，两个案例中的三个样本在使用 AmpFlSTRs Identifiler PCR 扩增试剂盒时在 CSF1PO 基因座上明显表现为纯合子，但使用 PowerPlexs 16 试剂盒时，这三个个体被发现为杂合子。这个令人困惑的问题通过使用多种分析方法得到了解决，包括使用不同的引物对和对导致“无效等位基因”的突变进行特征描述。缺失是由正向引物的假定结合位点的单个突变事件引起的。虽然这些沉默等位基因的频率仍然很低（在我们的研究中为 0.5%），但建议在数据库比较时应采取适当的措施，并通过序列分析进一步研究等位基因缺失，并向法医界报告。
