This study developed epigenetic methylation data for two genetic loci, GRIA2, and NPTX2, which were tested for prediction of age from the biofluids of a sample of donors of various ages.
The study analyzed 44 saliva samples and 23 blood samples from volunteers with ages from 5 to 72 years. DNA was extracted and bisulfite modified using commercial kits. Specific primers were used for amplification, and methylation profiles were determined by pyrosequencing. Methylation data from both markers and their relationship with age were determined using linear regression analysis, which indicates a positive correlation between methylation and age. Older individuals had increased methylation in both markers compared to younger individuals; this trend was more pronounced in the GRIA2 locus when compared to NPTX2. The epigenetic predicted age, calculated using a GRIA2 regression analysis model, was strongly correlated to chronological age (R2 = 0.801), with an average difference of 6.9 years between estimated and observed ages. A NPTX2 regression model showed a lower correlation between predicted and chronological age (R2 = 0.654), with an average difference of 9.2 years. The data indicate these loci can be used as a novel tool for age prediction, with potential applications in many areas, including clinical and forensic investigations. (Publisher abstract modified)