Age Estimation in Living Egyptians Using Signal Joint T‐cell Receptor Excision Circle Rearrangement

Abstract

Age estimation is one of the challenges in forensic sciences. There are many techniques to estimate the age. Molecular biology approach is one of these techniques. Signal joint T-cell receptor excision circles gene (sjTRECs), is one of this approach. We aimed to use sjTRECs as a suitable marker for age estimation among Egyptian population. TaqMan qPCR approach was used to quantify sjTREC levels in blood samples obtained from 153 healthy Egyptian individuals ranging from a few weeks to 70 years. Our results showed a significant negative correlation between sjTREC levels and age with p ≤ 0.05. Moreover, the individual's age can be determined through this formula Age = -30.671+ (-5.998Y) (Y is dCtTBP - sjTREC) with standard error ±7.35 years. Within the forensic context, sjTREC' levels can be used to estimate the Egyptian individual's age accurately.

Thymopoiesis in Pre- and Post-Hematopoietic Stem Cell Transplantation

“…A series of observations on TREC dynamics during human immunodeficiency virus (HIV) infection and treatment and in autologous and allogeneic hematopoietic stem cell transplantation (HSCT) confirmed the usefulness of TREC analysis as a quantitative marker for thymic function. Among these studies, some have shown that aging is an important contributor to damaged thymic function through decreased TREC quantification ( 17 – 19 ). Other studies have found a relationship between decreased TREC quantification and malignant disease treatment, or increased TREC quantification after highly active antiretroviral therapy (HAART) or HSCT as a sign of thymic function recovery ( 10 , 20 – 26 ).…”

Improvements and inter-laboratory implementation and optimization of blood-based single-locus age prediction models using DNA methylation of the ELOVL2 promoter

“…Several studies have aimed to identify potential biological and/or molecular biomarkers of aging correlating with chronological age and to use them to develop age prediction models 3,4 . Four types of DNA-based biomarkers of aging have been identified among the molecular biomarkers: telomere length 3,5,6 , mitochondria mutations 6,7 , signal joint T-cell receptor rearrangement excision circles and DNA methylation [8][9][10][11] .…”

A cautionary note on altered pace of aging in the COVID-19 era

“…It is quantified by a non-replicating circle of DNA called signal joint T-cell receptor excision circle (sjTREC) in naïve T cells using real-time polymerase chain reactions (q-PCR). The sjTREC was found to be negatively correlated to the chronological age albeit the models computed for sjRECs produced SEE of age estimation ranging between 7 years up to ~12 years [14] , [15] .…”

“…Over the past two decades, a plethora of forensic genetic and epigenetic studies suggested that DNA methylation (DNAm) and telomere length (TL) have a remarkable ability to predict the chronological age of the individual using various biological substrates [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] . The majority of DNAm models exhibit the lowest standard error of estimates (SEE) that is kept below 5 years [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] with the exception of one validation study [4] due to inter-laboratories variations.…”