Soldati Giulia, Saccardo Chiara, Raniero Dario, De Leo Domenico, Turrina Stefania
Department of Diagnostics and Public Health, Section of Forensic Medicine, Forensic Genetics Lab, University of Verona, Verona, Italy.
Int J Legal Med. 2025 Jan;139(1):61-65. doi: 10.1007/s00414-024-03341-w. Epub 2024 Oct 8.
In forensic genetics, sometimes formalin-fixed paraffin-embedded (FFPE) biopsy material taken during life is the only biological sample available for individual identification or paternity testing. In most cases, this biological tissue is characterized by the presence of tumor cells characterized by instability and loss of heterozygosity of microsatellites (MSI/LOH) compared to the DNA present in cells of normal tissue.In this case report, two FFPE samples from the same male subject were available for genetic investigation: one sample with colorectal cancer tissue and the other with normal tissue (no cancerous histopathological features). The comparison of the genetic profiles obtained from DNA extracted from the two tissues showed in the tumor tissue the presence of three genomic instability phenomena affecting FGA, CSF1P0, D21S2055 loci, located on three distinct autosomal chromosomes, and one duplication phenomenon affecting the DYS438. Therefore, due to the MSI/LOH phenomena, the genetic profile acquired from the tumor tissue was distorted and thus generated a fictitious genetic profile, not corresponding to the subject's real one (normal tissue free of tumor cells).
在法医遗传学中，有时生前采集的福尔马林固定石蜡包埋（FFPE）活检材料是可用于个体识别或亲子鉴定的唯一生物样本。在大多数情况下，与正常组织细胞中的DNA相比，这种生物组织的特征是存在具有微卫星不稳定性和杂合性缺失（MSI/LOH）特征的肿瘤细胞。在本病例报告中，有来自同一男性受试者的两个FFPE样本可用于基因研究：一个样本含有结直肠癌组织，另一个样本含有正常组织（无癌组织病理学特征）。对从这两种组织中提取的DNA获得的基因图谱进行比较，结果显示在肿瘤组织中存在三种影响FGA、CSF1P0、D21S2055基因座的基因组不稳定性现象，这些基因座位于三条不同的常染色体上，以及一种影响DYS438的重复现象。因此，由于MSI/LOH现象，从肿瘤组织获得的基因图谱发生了畸变，从而产生了一个虚构的基因图谱，与受试者真实的基因图谱（无肿瘤细胞的正常组织）不符。
