Usefulness of telomere length in DNA from human teeth for age estimation
Age estimation is widely used to identify individuals in forensic medicine. However, the accuracy of the most commonly used procedures is markedly reduced in adulthood, and these methods cannot be applied in practice when morphological information is limited. Molecular methods for age estimation have been extensively developed in the last few years. The fact that telomeres shorten at each round of cell division has led to the hypothesis that telomere length can be used as a tool to predict age. The present study thus aimed to assess the correlation between telomere length measured in dental DNA and age, and the effect of sex and tooth type on telomere length; a further aim was to propose a statistical regression model to estimate the biological age based on telomere length. DNA was extracted from 91 tooth samples belonging to 77 individuals of both sexes and 15 to 85 years old and was used to determine telomere length by quantitative real-time PCR. Our results suggested that telomere length was not affected by sex and was greater in molar teeth. We found a significant correlation between age and telomere length measured in DNA from teeth. However, the equation proposed to predict age was not accurate enough for forensic age estimation on its own. Age estimation based on telomere length in DNA from tooth samples may be useful as a complementary method which provides an approximate estimate of age, especially when human skeletal remains are the only forensic sample available.
KeywordsAge estimation Teeth Telomere length Quantitative real-time PCR
Appreciation is expressed to the Biopsia líquida y metástasis and Genética de las hemopatías malignas y complicaciones asociadas research groups from GENYO (Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica) for their technical support. We also thank Dr. Alfonso Varela-López for his methodological expertise and scientific advice and K. Shashok for improving the use of English in the manuscript. The authors also acknowledge funding from CEIFA (Centro para la Excelencia en Investigación Forense en Andalucía). This research was supported by an FPU (Formación de Profesorado Universitario) grant from the Spanish Ministry of Education, Culture and Sports to Ana Belén Márquez-Ruiz (FPU13/03543).
Compliance with ethical standards
The research protocol was approved by the Ethics Committee for Human Research of the University of Granada (Spain), and the study was conducted in accordance with the ethical standards laid down by the Declaration of Helsinki.
Conflict of interest
The authors declare that they have no conflict of interest.