Rubocki R J, Duffy K J, Shepard K L, McCue B J, Shepherd S J, Wisecarver J L
Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68198-5454, USA.
J Forensic Sci. 2000 Sep;45(5):1087-9.
Short tandem repeat (STR) markers are commonly used in basic genetic research and in human identification testing. Clinically, STRs can be used to study genetic alterations in tumors. A genetic deletion common to many types of cancer is referred to as the loss of heterozygosity (LOH). Numerous examples of LOH in cancer have been described and some have been mapped to areas located in close proximity to markers employed in human identity testing. Despite this fact, LOH has rarely been observed for STR loci commonly employed in forensic testing. Recently, for medico-legal purposes, we were asked to determine whether a tissue biopsy originated from a particular individual. For a reference source we assessed two specimens, one from normal tissue and one from cancerous tissue. When both reference specimens were used to generate DNA profiles, we observed LOH at one STR locus, D13S317. As demonstrated in other cancers only the cancerous biopsy demonstrated LOH. The forensic community should be cognizant of these unusual circumstances because, as identification of human DNA continues to be used more extensively, certain instances will arise in which reference material will not be readily available. In these situations, archived specimens may be employed as a reference source. Clinical specimens such as tissue biopsies should be used with caution if they have not been confirmed to contain normal tissue.
短串联重复序列（STR）标记常用于基础遗传学研究和人类身份鉴定测试。在临床上，STR可用于研究肿瘤中的基因改变。许多类型癌症中常见的一种基因缺失被称为杂合性缺失（LOH）。癌症中LOH的众多例子已被描述，其中一些已被定位到与人类身份测试中使用的标记紧邻的区域。尽管如此，法医检测中常用的STR位点很少观察到LOH。最近，出于法医学目的，我们被要求确定一份组织活检样本是否来自某一特定个体。作为参考来源，我们评估了两份样本，一份来自正常组织，一份来自癌组织。当使用两份参考样本生成DNA图谱时，我们在一个STR位点D13S317观察到了LOH。正如在其他癌症中所证明的那样，只有癌组织活检显示出LOH。法医界应该认识到这些特殊情况，因为随着人类DNA鉴定的使用越来越广泛，某些情况下将无法轻易获得参考材料。在这些情况下，可以使用存档样本作为参考来源。如果未经证实含有正常组织，临床样本如组织活检应谨慎使用。
