任苹 林琳 吴淑珍

[摘要]目的通过对亲权关系中牙釉质基因 Y 片段缺失的案例进行报道，分析其对亲子鉴定中结果的影响及解决方法。方法采用聚苯乙烯二乙烯基苯树脂（chelex）法提取被鉴定人样本的 DNA，使用 AGCU EX22与 AGCU Database Y24人类荧光标记 STR 复合扩增检测试剂进行复合 PCR 扩增，使用 ABI-3500遗传分析仪电泳检测，使用GeneMapper? ID-X 1.5软件分析结果。结果结果显示子的牙釉质基因扩增 Y 片段缺失，仅检測到Amel-X，系染色体片段Amel-Y 缺失所致，本次检测的所有 STR 基因座均进行多次检验，并排除污染的可能性。结论在亲子鉴定中如遇到Amel-Y 缺失时，应综合分析检验结果，并增加试剂盒检验，避免结果中对被鉴定人性别的误判，本案例报道为亲子鉴定领域中Amel-Y 缺失的案件，提供了一定的参考思路及解决方法。

[关键词]法医物证学;亲子鉴定; Y 染色体基因缺失;牙釉质基因

[中图分类号] D919.4  [文献标识码] A   [文章编号]2095-0616（2021）24-0237-04

A case of Y segment deletion of enamel gene in paternity test

REN  Ping    LIN  Lin    WU  Shuzhen

Department of Forensic Material Evidence， Wenzhou Medical University Forensic Center， Zhejiang， Wenzhou 325000，China

[Abstract] Objective To investigate the impacts of Y segment deletion of enamel gene in the results of paternity test and its solutions， its case was reported in this paper. Methods The method of polystyrene divinylbenzene resin （chelex） was used to extract the DNA of the identified human samples， and the compound PCR was carried out by using AGCU EX22 and AGCU Database Y24 human fluorescence labeled STR compound amplification detection reagent. Electrophoresis was performed by using ABI-3500 genetic analyzer， and the results were analyzed by using GeneMapper? ID-X 1.5 software. Results The results showed that the amplification of enamel gene in the offspring resulted in the deletion of Y segment， and only Amel-X was detected in the sample， which was caused by the deletion of Amel-Y chromosome segment. All STR loci detected this time were tested for many times， and the possibility of contamination was ruled out. Conclusion In case of Amel-Y deletion in paternity test， the test results shall be comprehensively analyzed， and the kit test shall be increased to avoid misjudgment of the identified gender in the results. This case report provides some reference ideas and solutions for the case of Amel-Y deletion in the field of paternity test.

[Key words] Forensic material evidence; Paternity test; Y chromosome gene deletion; Enamel gene

性别鉴定是法医鉴定的一个重要步骤，特别是在强奸案件及烧焦腐烂尸体或其他侦破刑事案件时，而Amelogenin基因的扩增是性别鉴定的重要方法，已被广泛应用在法医案件的侦破过程中[1-4]。而在亲子鉴定中，Amelogenin基因的应用尤为广泛，目前它包含在多种常染色体 STR 检测的试剂盒中，如 AGCU EX22、AGCU 21+1人类荧光标记 STR 复合扩增检测试剂（无锡中德美联生物技术有限公司）、SifaSTR23人类荧光标记 STR 复合扩增检测试剂（司法部司法鉴定科学技术研究院）等。尽管目前使用Amelogenin基因的试剂盒相对成熟，但是由于 Y 染色体釉原蛋白区域的缺失率高于 X 染……