亲子鉴定中STR基因座来源不明突变的分析  

Analysis of unknown source mutation in STR loci in paternity testing

作　　者：兰菲菲[1] 丁红珂[1] 陈延冰 余丽华[1] 尹爱华[1] LAN Feifei;DING Hongke;CHEN Yanbing;YU Lihua;YIN Aihua(Medical Genetics Center,Guangdong Women and Children Hospital,Guangzhou 511442,Guangdong,China)

机构地区：[1]广东省妇幼保健院医学遗传中心,广东广州511442

出　　处：《检验医学》2021年第2期185-189,共5页Laboratory Medicine

基　　金：广东省医学科研基金项目(B2014021)。

摘　　要：目的探讨亲子鉴定中STR基因座的等位基因突变来源不明的现象、原因及亲权指数计算。方法采用Chelex-100法提取4385例家系样本DNA,经聚合酶链反应(PCR)扩增后,应用毛细管电泳分析STR基因座的等位基因分型。发生突变的STR基因座,分别采用Identifiler体系或Microreader 23sp ID体系证实,同时用单基因座引物扩增测序的方法验证。结果2个家系分别在D12S391基因座、TPOX基因座和D8S1179基因座发生了来源不明的突变。不同检测体系证实了突变发生的真实性,测序结果分析发现,D12S391基因座和TPOX基因座的突变来源于母亲,均为一步突变。结论STR基因座来源不明的突变对该基因座亲权指数的计算有较大影响,进而影响鉴定结论。对于来源不明的突变应设计引物单独扩增STR基因座后通过测序验证其来源,正确计算亲权指数,保证鉴定结论的准确性和科学性。Objective To investigate the phenomenon,reason and parentage index calculation of unsure mutation source in STR loci in paternity testing.Methods Chelex-100 method was used to extract DNA from 4385 family samples.The allele genotyping of STR loci was analyzed by capillary electrophoresis after amplification with polymerase chain reaction(PCR).Mutated STR loci were verified by Identifiler system or Microreader 23sp ID system,respectively,and then validated by locus-specific primer amplification and sequencing.Results Mutations of unsure source were found in D12S391,TPOX and D8S1179 loci in two families.The authenticity of the mutation occurrence was confirmed by different detection systems.Sequencing results showed that the mutations of D12S391 and TPOX loci came from their mother,and both were one-step mutations.Conclusion Mutations of unknown source of STR locus has great influence on the calculation of the parentage indexand the identification conclusion.For mutations of unknown source,primers should be designed for amplification and sequencing to verify the source.The parentage index should be calculated correctly to ensure the accuracy and scientificity of the identification conclusion.

关 键 词：亲子鉴定 来源不明突变 D12S391基因座 TPOX基因座 

分 类 号：R446.7[医药卫生—诊断学]