Abstract
Biological evidence recovered from crime scenes is often subject to environmental conditions or suffers significant degradation, which can limit the accuracy of routine forensic genetic analyses. With their high stability and tissue-specific expression profiles, microRNAs (miRNAs) are emerging as promising forensic biomarkers for overcoming these limitations. This review focuses on the roles of miRNAs in the identification of body fluids, such as blood, semen, saliva, and vaginal secretions, as well as their current applications in postmortem interval (PMI) estimation, age determination, differentiation of monozygotic twins and forensic toxicology. While literature findings demonstrate that miRNAs provide robust results even in degraded samples, they also highlight significant methodological differences between the panels, reference genes, and analytical platforms employed.
Ultimately, miRNAs have significant potential as biomarkers in forensic genetics due to their high stability, tissue specificity, and wide range of applications. Nevertheless, due to shortcomings in the selection of reference genes, normalization strategies, and standardization of analytical workflows, no miRNA-based forensic test has yet been adopted for routine use. In the foreseeable future, the accuracy and clinical applicability of miRNA-based analyses are expected to improve through the integration of next-generation sequencing technologies, multi-biomarker panels, exosomal miRNA analyses, and artificial intelligence-supported data evaluation approaches into forensic applications. Consequently, the conduct of large-scale validation studies and the development of standardized analytical protocols to ensure inter-laboratory reproducibility are of critical importance from a forensic perspective.
Keywords
miRNA, Forensic genetics, Body fluid identification, Postmortem interval, Age estimation, Monozygotic twins