摘要
目前亲缘鉴定中,通过检测常染色体STR基因座并依据ITO法计算半同胞指数可以推测被鉴定人之间是否存在亲缘关系.然而ITO法计算似然率有时无法得到明确的判断依据,对此可以检测多个遗传标记辅助判断并采用不同计算方法综合分析,以获得确定亲缘关系的证据支持.笔者在实际工作中曾受理一起同母异父半同胞鉴定案例,通过检测常染色体STR、mtDNA和SNP等遗传标记,并综合运用ITO、判别函数、线粒体高变区多态性、基于等位基因频率估计的状态一致性推断亲缘关系等级等多种分析方法,最终获得了可靠的鉴定结果.
Abstract
At present,in genetic identification,the detection of autosomal STR loci and the calculation of half sibling index using the ITO method can infer whether there is a genetic relationship among the identified individuals.However,the ITO method sometimes cannot provide a clear judgment basis for calculating likelihood rates.Therefore,multiple genetic markers can be detected to assist in judgment and different calculation methods can be used for comprehensive analysis to obtain evidence support for determining genetic relationships.Half sibling identification is a difficult point in genetic relationship identification,especially in heterosexual half sibling relationships,which cannot be assisted by the genetic rules of X-STR or Y-STR,which further increases the risk and difficulty of identification.In the case where only two individuals participate in identification,it is also impossible to analyze through family reconstruction methods.Therefore,in a case of half sibling relationship identification,this article detected genetic markers such as autosomal STR,mtDNA,and SNP,and comprehensively used various analysis methods such as ITO,discriminant function,mitochondrial high variability region polymorphism,and state consistency based on allele frequency estimation to infer the degree of kinship.Through mutual verification of multiple genetic marker detection results,reliable identification results were finally obtained.