摘要
目的探讨三等位基因的类型和特点,为司法实践中法医鉴定人正确研判三等位基因现象提供科学依据。方法收集来自西安交通大学法医学司法鉴定中心6个案例样本,利用Chelex-100提取DNA,通过复合PCR扩增和毛细管电泳进行STR基因型分析。结果39个STR等位基因中检出5个具有三等位基因的基因座,其中D18S51基因座检出3例,D21S11检出2例,D2S441、D2S1338及D21S1270各检出1例,采用不同试剂盒验证结果均一致。Type1型表现峰高面积不均衡,检出率为50%(4/8);Type2型表现峰高面积均衡,检出率为50%(4/8)。测序结果证实,D2S441为位于2p14的简单序列STR基因座,重复单位TCTA;D2S1338为位于2q35的复合序列STR基因座,重复单位TGCC和TTCC。结论在DNA鉴定中遇到三等位基因,需用不同试剂盒验证,或者增加性染色体基因座检测,亲权指数计算时须慎重。
Objective Exploring the types and characteristics of three alleles providing scientific basis for forensic appraisers to accurately analyze and determine the phenomenon of three alleles in judicial practice.Methods Collect 6 case samples from the Forensic Medicine Judicial Identification Center of Xi'an Jiaotong University,DNA was extracted using Chelex⁃100,and STR genotyping was analyzed by multiplex PCR amplification and capillary electrophoresis.Results The showed that 5 out of 39 STR alleles were detected with three alleles,including D18S51(3 cases),D21S11(2 cases),and D2S441(1 cases),D2S1338(1 cases),and D21S1270(1 cases).The results were consistent using different reagent kits,and the peak height area of the type 1 phenotype was uneven,with a detection rate of 50%(4/8);type 2 exhibits a balanced peak height and area,with a detection rate of 50%(4/8).Sequencing confirmed that D2S441 is the simple sequence STR locus at 2p14,repeat unit TCTA,and D2S1338 is the complex sequence STR locus at 2q35,repeat units TGCC and TTCC.Conclusion When encountering three alleles in DNA identification,different reagent kits need to be used for verification,or the addition of alleles in sex chromosomes,parental index should be calculated carefully.
作者
贾小妮
焦杨
张洪波
余兵
魏曙光
JIA Xiaoni;JIAO Yang;ZHANG Hongbo;YU Bing;WEI Shuguang(School of Forensic Medicine,Xi'an Jiaotong University,Xi'an,Shaanxi 710000,China;BGl Shaanxi Institute of Forensic Science,Xi'an,Shaanxi 710000,China;The Second Affiliated Hospital of Xi'an Jiaotong University,Xi'an,Shaanxi 710000,China)
出处
《热带医学杂志》
CAS
2024年第4期486-489,共4页
Journal of Tropical Medicine
基金
陕西省自然科学基金(2003C202)。
