The Y chromosome and its use in forensic DNA analysis

Abstract

Originally relatively ignored in forensic investigations because its genetic analysis lacks inference of individual identification, the value of Y chromosome analysis has been proven in cases of sexual assault, particularly where the amount of material left by a male assailant is limited in comparison with female DNA. All routine analysis of autosomal DNA, however, targets a gene (AMELY) on the Y chromosome in order to identify the sex of the DNA source and this is discussed in the context of the genetic structure of this male-specific chromosome. Short-tandem repeat markers on the chromosome are tested in dedicated multiplexes that have developed over time and these are described alongside international guidance as to their use in a forensic setting. As a marker of lineage, the Y chromosome provides additional tools to assist in the inference of ancestry, both geographical and familial and the value of Y chromosome testing is illustrated through descriptions of cases of criminal and historical interest. A decision to analyse the Y chromosome has to be considered in the context, not only of the circumstances of the case, but also with regard to the ethical questions it might raise, and these are discussed in relation to the cases that have been described in more detail in the accompanying online supplementary material.

Identification of the Remains of an Adult Using DNA from Their Deciduous Teeth as a Reference Sample

“…Furthermore, it has been observed that the inclusion of more loci does not compensate for the absence of genetic information from the mother or the father [35,40,[42][43][44]. The use of Y-chromosome STRs can help only when the victim is male, and the possibility that a close relative of the putative father is the biological father cannot be ruled out [45]. X-chromosome STRs must be analyzed along with other genetic markers to obtain useful data and can only be used with accuracy when the victim is female, as there are no X-chromosome alleles inherited by descent in a father-son relationship [46].…”

Recent advances in forensic biology and forensic DNA typing: INTERPOL review 2019–2022

“…Several recent review articles were published on forensic applications of Y-chromosome testing [ [444] , [445] , [446] ]. As discussed previously in Section 1.2 , an ISFG DNA Commission summarized the state of the field with Y-STR interpretation [ 39 ].…”

Design and development of novel single multiplex system incorporating 26 rapidly mutating Y‐STRs; 26 RM Yplex

“…In real‐case scenarios, depending solely on Y‐STR is far from enough. This means that even if there was a 100% Y‐STRs match between a sample and a suspect, we cannot differentiate the contributor from his patrilineal lineages [ 6 , 8 ]. To address this problem, scientists worked hard and discovered new Y‐STRs with high mutation rates, called rapidly mutating (RM) Y‐STRs.…”