Tozzo P, Giuliodori A, Corato S, Ponzano E, Rodriguez D, Caenazzo L
Department of Molecular Medicine, University of Padova, 35121 Padova, Italy.
J Forensic Leg Med. 2013 Jul;20(5):387-91. doi: 10.1016/j.jflm.2013.03.012. Epub 2013 Apr 12.
Today, the molecular technique routinely for sex determination in forensics is based the detection of length variations in the X-Y homologous amelogenin gene (AMELX and AMELY). In humans, the amelogenin gene is a single-copy gene located on Xp22.1-Xp22.3 and Yp11.2; the simultaneous detection of the X and Y alleles using polymerase chain reaction (PCR) can lead to gender determination. Several studies have shown that normal males may be typed as females with this test: AMELY deletions may result in no product of amplification and normal males being typed as female as a result of the test (negative male). Considering the consequences of the result obtained using only the amelogenin marker, and the related potential difficulties in interpreting the results, the gender misinterpretation may be troublesome in clinical practice and in forensic casework. In this article, beginning with a review of the incidence of gender-testing failures among different populations, and with the different strategies proposed in the literature in case of doubt regarding the presence of deleted AMEL in the DNA profile, we propose a method for the identification of samples with deleted AMEL that can be applied, as an additional assay, in case of doubt regarding PCR results of sex determination.
如今，法医鉴定中常规用于性别鉴定的分子技术是基于检测X - Y同源牙釉蛋白基因（AMELX和AMELY）的长度变异。在人类中，牙釉蛋白基因是位于Xp22.1 - Xp22.3和Yp11.2的单拷贝基因；使用聚合酶链反应（PCR）同时检测X和Y等位基因可进行性别鉴定。多项研究表明，正常男性在该检测中可能被判定为女性：AMELY缺失可能导致无扩增产物，进而使正常男性在检测中被判定为女性（男性阴性）。考虑到仅使用牙釉蛋白标记物所获结果的后果以及解读结果时相关的潜在困难，性别误判在临床实践和法医案件工作中可能会造成麻烦。在本文中，我们首先回顾不同人群中性别检测失败的发生率，以及文献中针对DNA图谱中是否存在缺失的AMEL存疑时提出的不同策略，然后提出一种鉴定存在AMEL缺失样本的方法，该方法可作为一种补充检测，在性别鉴定PCR结果存疑时应用。
