Estimation of Cadaveric Age by Ultrasonography.

(1) Background: While decreasing bone mineral density (BMD) with age in living people has been well documented, a correlation between age and bone mineral density in deceased people has only been reported in a few studies. A correlation between age and BMD in deceased people was investigated as an objective tool for age estimation of unidentified remains. (2) Methods: The Bone Area Ratio (BAR) was measured in 402 autopsy cases (143 females and 259 males over the age of 20). (3) Results: The correlation coefficient in the females was r = -0.5476, and the correlation coefficient in the males was r = -0.2166, indicating a stronger correlation in females than in males. A comparison of the BAR values in the deceased females for each age group with that in live females found no significant differences in the BAR values. BAR values in the deceased were similar to in live individuals, and this did not change with duration of the postmortem interval. (4) Conclusions: Measuring the BAR value based on bone mass using ultrasonic waves is rapid and easy, even for those lacking forensic training, and may be used to estimate the age of an individual and the likelihood of fracture due to trauma.

DNA methylation age estimation in blood samples of living and deceased individuals using a multiplex SNaPshot assay.

Many studies in the forensic field have reported that analysis of DNA methylation is the most reliable method of predicting age. In a previous study, 5 CpG sites located in ELOVL2, FHL2, KLF14, C1orf132 and TRIM59 genes were tested for age prediction purposes in blood, saliva and buccal swab samples from Korean individuals using a multiplex methylation SNaPshot assay. The main goals of the present study were i) to replicate the same multiplex SNaPshot assay in blood samples from Portuguese individuals, ii) to compare DNA methylation status between two different populations and iii) to address putative differences in the methylation status between blood from living and deceased individuals. Blood samples from 59 living individuals (37 females, 22 males; aged 1-94 years-old) and from 62 deceased individuals (13 females, 49 males; aged 28-86 years-old) were evaluated. The specific primers were those previously described. Linear regression models were used to analyse relationships between methylation levels and chronological age using IBM SPSS software v.24. Our results allowed to build a final age prediction model (APM) for blood samples of living individuals with 3 CpG sites, at ELOVL2, FHL2 and C1orf132 genes, explaining 96.3% of age variation, with a mean absolute deviation (MAD) from chronological age of 4.25 years. Some differences were found in the extent of the age association in the targeted loci comparing Portuguese with Korean individuals. The final APM built for deceased individuals included 4 CpG sites, at ELOVL2, FHL2, C1orf132 and TRIM59 genes, explaining 79.3% of age variation, with a MAD of 5.36 years. Combining both sets of samples from living and deceased individuals, the most accurate APM with 4 CpGs, at ELOVL2, FHL2, C1orf132 and TRIM59 genes, explained 92.5% of variation in age, with a MAD of 4.97 years. In conclusion, our study replicated in blood samples of Portuguese living individuals a previous SNaPshot assay for age estimation. The possibility that age markers might be population specific and that postmortem changes can alter the methylation status among specific loci was suggested by our data. Our study showed the usefulness of the multiplex methylation SNaPshot assay for forensic analysis in blood samples of living and deceased individuals.

Age Estimation Based on DNA Methylation Using Blood Samples From Deceased Individuals.

Age estimation using DNA methylation levels has been widely investigated in recent years because of its potential application in forensic genetics. The main aim of this study was to develop an age predictor model (APM) for blood samples of deceased individuals based in five age-correlated genes. Fifty-one samples were analyzed through the bisulfite polymerase chain reaction (PCR) sequencing method for DNA methylation evaluation in genes ELOVL2, FHL2, EDARADD, PDE4C, and C1orf132. Linear regression was used to analyze relationships between methylation levels and age. The model using the highest age-correlated CpG from each locus revealed a correlation coefficient of 0.888, explaining 76.3% of age variation, with a mean absolute deviation from the chronological age (MAD) of 6.08 years. The model was validated in an independent test set of 19 samples producing a MAD of 8.84 years. The developed APM seems to be informative and could have potential application in forensic analysis.