Rapidly mutating Y-STR analyses of compromised forensic samples.

Area of Science:

• Forensic Genetics
• Human Identity Testing
• Ancient DNA Analysis

Background:

• Rapidly mutating Y-chromosomal short tandem repeats (RM Y-STRs) enhance male differentiation in forensic and kinship analyses.
• The RM-Yplex assay was developed to simultaneously amplify all known RM Y-STRs.

Purpose of the Study:

• To evaluate the RM-Yplex assay's performance on compromised forensic samples, specifically ancient DNA.
• To assess the assay's suitability for analyzing DNA from ~70-year-old skeletal remains.

Main Methods:

• Application of the RM-Yplex assay to 57 male skeletal samples (bones and teeth) from WWII mass graves.
• Analysis of DNA quantity, degradation, and locus dropout rates.

Main Results:

• Successful RM-Yplex typing was achieved in all 57 ancient DNA samples.
• 56% of samples yielded full profiles, with locus dropouts observed in partial profiles, correlated with DNA degradation.
• Longer loci (DYS403S1b, DYS547, DYS627, DYS526b) showed higher dropout frequencies.

Conclusions:

• The RM-Yplex assay is effective for analyzing highly degraded DNA from challenging forensic samples like ancient skeletal remains.
• Even with dropouts, the assay can amplify a significant portion of RM Y-STRs from compromised samples, aiding in identification.