DNA extraction from filter-paper spots of vaginal samples collected after sexual violence

Molecular analysis for sex determination in forensic dentistry: a systematic review

Background

Sex determination can be useful in forensic casework, such as in mass disasters, transportation accidents, and cases of a missing person or sexual assault. The remnants of the body can be traced by DNA of the victim, using samples from various sources such as teeth, oral epithelial tissue, and saliva.

Main body

The review aimed to describe research in forensic dentistry with DNA source from the oral region and methods of the applied DNA analysis. A search in PubMed, Google Scholar, and Scopus electronic databases from 2009 to 2019 was conducted to include studies according to PRISMA guidelines. Ten studies were eligible for the review. Genetic markers originated from dentin, dental pulp, saliva, or epithelial cells from buccal tissue and prosthesis. The applied DNA analysis methods were PCR, real-time PCR, and nested PCR.

Conclusions

The published articles mostly showed successful DNA extraction and sex determination, but the rate of success declined as the sample source underwent manipulation to mimic the forensic conditions. Amelogenin, SRY, and DYS14 were reliable indicators for sex determination. Molecular analysis has proved to be efficient and accurate, but the daily forensic practice must select the most appropriate method according to the available body remnants.

Genetic sex determination assays in 53 mammalian species: Literature analysis and guidelines for reporting standardization

Erstwhile, sex was determined by observation, which is not always feasible. Nowadays, genetic methods are prevailing due to their accuracy, simplicity, low costs, and time-efficiency. However, there is no comprehensive review enabling overview and development of the field. The studies are heterogeneous, lacking a standardized reporting strategy. Therefore, our aim was to collect genetic sexing assays for mammals and assemble them in a catalogue with unified terminology. Publications were extracted from online databases using key words such as sexing and molecular. The collected data were supplemented with species and gene IDs and the type of sex-specific sequence variant (SSSV). We developed a catalogue and graphic presentation of diagnostic tests for molecular sex determination of mammals, based on 58 papers published from 2/1991 to 10/2016. The catalogue consists of five categories: species, genes, SSSVs, methods, and references. Based on the analysis of published literature, we propose minimal requirements for reporting, consisting of: species scientific name and ID, genetic sequence with name and ID, SSSV, methodology, genomic coordinates (e.g., restriction sites, SSSVs), amplification system, and description of detected amplicon and controls. The present study summarizes vast knowledge that has up to now been scattered across databases, representing the first step toward standardization regarding molecular sexing, enabling a better overview of existing tests and facilitating planned designs of novel tests. The project is ongoing; collecting additional publications, optimizing field development, and standardizing data presentation are needed.