Novel age estimation strategy based on blood transfer RNA-derived small RNAs: a preliminary study

Age estimation can offer additional information to inform an investigation. The determination can assist in directing investigators towards putative victims and narrowing the scope of the investigation. Age-related skeletal development and epigenetic clocks have been broadly applied in forensic age estimation. However, challenges in age estimation include the requirement for high-quality samples and cumbersome detection methods. Small noncoding RNAs have attracted the interest of forensic researchers owing to their low molecular weight and high stability. Transfer RNA-derived small RNA (tsRNA) is a newly discovered small RNA. Increasing evidence indicates that tsRNA has the potential as a biomarker for age estimation. In this study, 16 age-related tsRNAs recovered from blood were identified using massive parallel sequencing technology. Four tsRNAs were verified by real-time fluorescence quantitative polymerase chain reaction, and three age-related tsRNAs were used to establish age estimation models. The support vector machine regression model performed best with a mean absolute error of 6.38 years (R² = 0.36) in the participants with an age range from 19 to 53. This study provides the first evidence that age can be estimated using tsRNA biomarkers. The use of small noncoding RNAs as biomarkers is a promising approach for age estimation in forensic samples.