Human Organ Tissue Identification by Targeted RNA Deep Sequencing to Aid the Investigation of Traumatic Injury.

Erin Hanson,Jack Ballantyne

doi:10.3390/genes8110319

Abstract

Molecular analysis of the RNA transcriptome from a putative tissue fragment should permit the assignment of its source to a specific organ, since each will exhibit a unique pattern of gene expression. Determination of the organ source of tissues from crime scenes may aid in shootings and other investigations. We have developed a prototype massively parallel sequencing (MPS) mRNA profiling assay for organ tissue identification that is designed to definitively identify 10 organ/tissue types using a targeted panel of 46 mRNA biomarkers. The identifiable organs and tissues include brain, lung, liver, heart, kidney, intestine, stomach, skeletal muscle, adipose, and trachea. The biomarkers were chosen after iterative specificity testing of numerous candidate genes in various tissue types. The assay is very specific, with little cross-reactivity with non-targeted tissue, and can detect RNA mixtures from different tissues. We also demonstrate the ability of the assay to successful identify the tissue source of origin using a single blind study.

Highlights

A number of criminal cases requiring forensic investigation involve significant trauma to the human body, in which internal organ tissue is transferred from the injured party to another individual, item, or location [1]
Attempts were made to include the tissue-specific biomarkers from Lindenbergh et al [24] for consistency in forensic tissue identification assays for the six tissues in common between the two assays
Of the 13 candidates from the Lindenbergh assay [24], all genes were evaluated for use in the targeted RNA sequencing assay except the kidney biomarker FXYD2 (FXYD domain containing ion transport regulator 2), as no commercial off-the-shelf assay was readily available for this biomarker

Summary

Introduction

A number of criminal cases requiring forensic investigation involve significant trauma to the human body, in which internal organ tissue is transferred from the injured party to another individual, item, or location [1]. In combination with standard DNA analysis to identify the individual source of the transferred biological material, the positive identification and differentiation of the organ tissue from blood or other secreted body fluids can provide important probative information. The identification of traces of desiccated organ tissue can be problematic, and normally requires the expertise of a cellular pathologist and/or histologist, and the use of immunohistochemistry methods [2]. Many such tissues are intractable to such analysis due to limited material, and/or the fact that the cellular structures are non-canonical in appearance due to dehydration, and are difficult to discern due to limited quantity or crushing damage.

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