Telomere length and signal joint T-cell receptor rearrangement excision circles as biomarkers for chronological age estimation.

Background: Chronological age estimation is a challenging marker in the field of forensic medicine. The current study aimed to investigate the accuracy of signal joint T-cell receptor rearrangement excision circles (sjTRECs) quantification and telomere length measurement as methods for estimating chronological age.

Methods: Telomere length was estimated in the DNA derived from the buccal cells through estimating the telomeric restriction fragment (TRF) length using Telo Telomere Length Assay while the sjTRECs quantification was carried out on DNA isolated from the blood samples using qPCR.

Results: The TRF length was shortened with increased age ( = -0.722,  < 0.001). The sjTRECs were also decreased with increased age ( = -0.831,  < 0.001). Stronger coefficient and lower standard error of the estimate was obtained when multiple regression analysis for age prediction based on the values of both methods was applied ( = -0.876,  < 0.001).