Y chromosome STR typing in crime casework

Abstract

Since the beginning of the nineties the field of forensic Y chromosome analysis has been successfully developed to become commonplace in laboratories working in crime casework all over the world. The ability to identify male-specific DNA renders highly variable Y-chromosomal polymorphisms, the STR sequences, an invaluable addition to the standard panel of autosomal loci used in forensic genetics. The male-specificity makes the Y chromosome especially useful in cases of male/female cell admixture, namely in sexual assault cases. On the other hand, the haploidy and patrilineal inheritance complicates the interpretation of a Y-STR match, because male relatives share for several generations an identical Y-STR profile. Since paternal relatives tend to live in the geographic and cultural territory of their ancestors, the Y chromosome analysis has a potential to make inferences on the population of origin of a given DNA profile. This review addresses the fields of application of Y chromosome haplotyping, the interpretation of results, databasing efforts and population genetics aspects.

Genetic diversity of 17 Y-chromosomal short tandem repeat loci in northeast Germany

“…Two mutations were observed at loci DYS456, DYS393, DYS391 and DYS385. The average mutation rate was 3.66 Â 10 À3 similar to results of other working groups obtained for Y-STRs [9][10][11][12]. All mutations were characterized by sequencing.…”

Development of an Italian RM Y-STR haplotype database: Results of the 2013 GEFI collaborative exercise

“…Moreover, due to their haploid nature and uniparental transmission favouring the geographical clustering of haplotypes, Y-STRs can provide intelligence information on the ethnic origin of a stain donor in non-suspect cases. The principal weakness of Y-STR analysis is that, even when a crime sample matches the Y-STR haplotype of a suspect, his patrilineal relatives cannot be excluded as being the donor of the stain [1]. Adding additional markers to the current sets of Y-STRs used in forensic casework can improve the level of paternal lineage differentiation [2].…”

Empirical Evaluation Reveals Best Fit of a Logistic Mutation Model for Human Y-Chromosomal Microsatellites

“…The Y chromosome is of particular interest in forensics because it allows easy discrimination between male and female contributions to traces and trace mixtures. This has led to a situation where a few Y-STRs are routinely genotyped in a vast number of individuals (Roewer 2009). Table 1 lists the six Y-STRs that have been included in the present study, along with their most important molecular characteristics.…”