PLoS ONE (Jan 2016)

Mutation Rates and Discriminating Power for 13 Rapidly-Mutating Y-STRs between Related and Unrelated Individuals.

  • Alessio Boattini,
  • Stefania Sarno,
  • Carla Bini,
  • Valeria Pesci,
  • Chiara Barbieri,
  • Sara De Fanti,
  • Andrea Quagliariello,
  • Luca Pagani,
  • Qasim Ayub,
  • Gianmarco Ferri,
  • Davide Pettener,
  • Donata Luiselli,
  • Susi Pelotti

DOI
https://doi.org/10.1371/journal.pone.0165678
Journal volume & issue
Vol. 11, no. 11
p. e0165678

Abstract

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Rapidly Mutating Y-STRs (RM Y-STRs) were recently introduced in forensics in order to increase the differentiation of Y-chromosomal profiles even in case of close relatives. We estimate RM Y-STRs mutation rates and their power to discriminate between related individuals by using samples extracted from a wide set of paternal pedigrees and by comparing RM Y-STRs results with those obtained from the Y-filer set. In addition, we tested the ability of RM Y-STRs to discriminate between unrelated individuals carrying the same Y-filer haplotype, using the haplogroup R-M269 (reportedly characterised by a strong resemblance in Y-STR profiles) as a case study. Our results, despite confirming the high mutability of RM Y-STRs, show significantly lower mutation rates than reference germline ones. Consequently, their power to discriminate between related individuals, despite being higher than the one of Y-filer, does not seem to improve significantly the performance of the latter. On the contrary, when considering R-M269 unrelated individuals, RM Y-STRs reveal significant discriminatory power and retain some phylogenetic signal, allowing the correct classification of individuals for some R-M269-derived sub-lineages. These results have important implications not only for forensics, but also for molecular anthropology, suggesting that RM Y-STRs are useful tools for exploring subtle genetic variability within Y-chromosomal haplogroups.