As expected, PPY23 provided higher discriminatory 17-AAG cell line power for forensic purposes than other marker sets in our data. Remarkably, in almost one third of the populations studied, each sample could be identified unambiguously because all haplotypes
in the population were unique. Most of the non-unique haplotypes were detected in populations that either passed through a recent bottleneck (e.g. Finland [33]) or that have a high reported degree of endogamy (e.g. Alaskan Natives and Kenyan Maasai). The higher number of unique haplotypes arising with PPY23 is a result of the larger number of markers in the kit and the preferential choice of markers with a higher discriminatory power. In particular, among the five Y-STRs with the highest diversity in our study, both globally and in GSK-3 inhibitor all meta-populations, three (DYS481, DYS570 and DYS576) were specific to PPY23. The practical utility of highly polymorphic
Y-chromosomal profiles, for example, in biological stain analysis results from the greatly decreased chance of coincidental matches among different individuals. In the case of non-identity, exclusion becomes overwhelmingly likely. On the other hand, use of the PPY23 kit in kinship analysis or familial searching will render these practices increasingly complex because even close relatives may exhibit one or more mismatches, particularly at loci with high mutation rates. For these applications, there should be mandatory use of likelihood-based approaches that take allele frequencies, mutation rates and the presumed degree of relatedness properly into account [34]. The performance of forensic analysis with degraded DNA has also improved with the advent of PPY23. Typically, only partial DNA profiles can be
generated from degraded DNA, with a pronounced dropout of longer amplicons. Compared to Yfiler, the short haplotypes of PPY23 (i.e. those comprising the eight markers with amplicons <220 bp) were much more variable. This difference is clearly due to the oxyclozanide high mutation rates of four of the six markers specific to PPY23 selected for a short amplicon length. Thus, it is likely that the PPY23 kit will greatly improve the analysis of aged or otherwise damaged DNA samples. The present study revealed a considerable number of null and duplicated alleles that were caused either by non-allelic homologous recombination between paralogous DNA sequences [35] or – in the case of nulls – by deletions or primer site mutations [36]. Compared to Yfiler, the PPY23 allelic ladder has been enriched with new length variants to accommodate the various intermediate alleles that were observed as well.