New Future of Forensic Y-Chromosome Analysis: Rapidly Mutating Y-STRs for Differentiating Male Relatives and Paternal Lineages

• NCJ Number: 240623
• Journal: Forensic Science International: Genetics Volume: 6 Issue: 2 Dated: March 2012 Pages: 208-218
• Author(s): Kaye N. Ballantyne; Victoria Keerl; Andreas Wollstein; Ying Choi; Sofia B. Zuniga; Arwin Ralf; Mark Vermeulen; Peter de Knijff; Manfred Kayser
• Date Published: March 2012
• Length: 11 pages
• Sponsoring Agency: Netherlands Organization for Scientific Research (NWO); Netherlands Forensic Institute
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: Ireland

Annotation

This study demonstrates in 604 unrelated males sampled from 51 worldwide populations (HGDP-CEPH) that the RM Y-STRs provide substantially higher haplotype diversity and haplotype discrimination capacity (with only 3 haplotypes shared between 8 of the 604 worldwide males), than obtained with the largest set of 17 currently used Y-STRs (Yfiler) in the same samples (33 haplotypes shared between 85 males).

Abstract

The panels of 9-17 Y-chromosomal short-tandem repeats (Y-STRs) currently used in forensic genetics have adequate resolution of different paternal lineages in many human populations, but have lower abilities to separate paternal lineages in populations expressing low Y-chromosome diversity. Moreover, current Y-STR sets usually fail to differentiate between related males who belong to the same paternal lineage and, as a consequence, conclusions cannot be drawn on the individual level as is desirable for forensic interpretations. Recently, the aithors identified a new panel of rapidly mutating (RM) Y-STRs, composed of 13 markers with mutation rates above 1 10(-2), whereas most Y-STRs, including all currently used in forensics, have mutation rates in the order of 1 10(-3) or lower. Hence, RM Y-STRs yield high-resolution paternal lineage differentiation and provide a considerable improvement compared to Yfiler. The study also foundind in this worldwide dataset substantially less genetic population substructure within and between geographic regions with RM Y-STRs than with Yfiler Y-STRs. Furthermore,the present study provides enhanced data evidence that the RM Y-STR panel is extremely successful in differentiating between closely and distantly related males. Among 305 male relatives, paternally connected by 1-20 meiotic transfers in 127 independent pedigrees, the study shows that 66 percent were separated by mutation events with the RM Y-STR panel; whereas, only 15 percent were with Yfiler; hence, RM Y-STRs provide a statistically significant 4.4-fold increase of average male relative differentiation relative to Yfiler. The RM Y-STR panel is powerful enough to separate closely related males; nearly 50 percent of the father and sons, and 60 percent of brothers could be distinguished with RM Y-STRs; whereas, only 7.7 percent and 8 percent, respectively, with Yfiler. Thus, by introducing RM Y-STRs to the forensic genetic community, this study provides important solutions to several of the current limitations of Y chromosome analysis in forensic genetics. (Published Abstract)