5个新的STR基因座的群体遗传学及法医学研究

目的开发新的STR遗传标记应用于法医学个人识别和亲子鉴定。方法采集成都汉族群体中113名无血缘关系个体的血样,对5个21号染色体STR基因座作PCR扩增,电泳分型。应用PowerStats软件分析等位基因频率和基因型分布,计算法医学应用理论值;采用2×2列联表及χ2检验,检验21号染色体上5个STR基因座之间是否相互独立。结果5个STR基因座的个人识别能力>0.85,非父排除率≥0.48;独立性检验证实5对基因座之间,即LFG21与LFG26、LFG20与LFG24、LFG21与LFG24、LFG24与LFG26以及LFG24与LFG29具有相对独立性,可在法医物证鉴定中同时应用。结论初步筛选出了4个可作为法医学应用的候选STR基因座:LFG21、LFG24、LFG26、LFG29。

Genetic polymorphism and forensic application of five novel STR loci

Objective To explore the novel STRs on human chromosome 21 for forensic applications.Methods A total of 113 samples were collected from unrelated Chengdu Han individuals.Five chromosome 21-specific loci were amplified by PCR,and PCR products were analyzed by gel electrophoresis.The PowerStats software was used to analyze the allele frequencies,and the forensic values of STRs loci were also calculated.The independence test was carried out in 5 STRs loci on chromosome 21 with χ2 test.Results The forensic values,estimated from the population data,revealed the discrimination powers of 5 STRs loci >0.85,and the exclusion probabilities ≥0.48.The independence test of 5 loci proved that there were no correlations between the two STRs in 5 pairs,which were LFG26 and LFG21,LFG20 and LFG24,LFG21 and LFG24,LFG24 and LFG26,LFG24 and LFG29.Therefore they could be used simultaneously.Conclusion The forensic study of 5 STRs on chromosome 21 revealed that LFG21,LFG24,LFG26 and LFG29 were good candidates as polymorphic markers for forensic DNA analysis.