法医SNP系谱推断技术助破14年久冷案

Forensic SNP Genealogical Inference Helping Ferret out a 14-yearlong Unsolved Cold Case

男性家族排查是目前法医DNA办案工作中的重要手段,但是同一父系几或十数代男性的Y-STR基因分型可能都相近甚至一致,若在全国范围内很可能比中不同地区的多个家系,当无法甄别所有比中家系与嫌疑人的亲缘关系远近时,办案单位就很难确定重点调查家系,而全部摸排则费时耗力。近期,公安部物证鉴定中心研发出了法医SNP系谱推断技术,通过检测和分析全基因组数据,可预测父系和母系的1~7级亲缘关系(高祖至玄孙,即五服),且能分析关系远近。将该技术与族群分析运用于一起长达14年未破的强奸杀人案,帮助办案单位确定了嫌疑人的地域来源、所在家系等信息,为案件的侦破提供了关键技术支撑。

Y-STR familial screening is at present an important resort for investigating male suspects with forensic DNA cases.However,the same paternal lineage may maintain the similar or identical Y-STR genotype for several or even dozens of generations,resulting in eligible matches falling into multiple paternal families in different regions nationwide.Nevertheless,Y-STR is incapable of analyzing the distance of kinship between all matched families and the suspect so that the relevant local police will be difficult to determine the target family because investigating all the matched families is both time-consuming and waste of resources.Recently,a SNP genealogy inference technology has been developed with Institute of Forensic Science,Ministry of Public Security,able to predict genetic kinship boastfully from 1st-to 7th-generation tiers through the genome-wide SNP data.As thus,such a technology,combined with the ancestry inference,was applied to investigating into a 14-year-long unsolved cold case of rape and murder,having assisted the local police to successfully determine the biogeography and family information of the suspect so as to provide key technical support for the case to resolve.