Y‐chromosome short tandem repeats in forensics—Sexing, profiling, and matching male DNA

Abstract

AbstractThe analysis of short tandem repeat (STR) markers located on the Y chromosome is an established method in forensic casework analysis. Usually this method is applied in cases of male‐on‐female sexual assault, in which the victim's DNA is in great excess and masked the male contribution. Y‐STR analysis is able to detect the presence of minuscule amounts of male DNA of one or multiple donors and resulting genetic profiles can be compared to known reference samples. The expert has to determine whether the Y‐STR result of a trace is suitable for a biostatistical calculation in case of a match. The Discrete Laplace method which is implemented in the Y chromosome haplotype reference database (YHRD) can be used to estimate haplotype frequencies with a better approximation than other methods namely the counting method. Moreover, Y‐SNPs in combination with Y‐STRs can infer the biogeographical origin of an unknown male person with comparably high precision due to the availability of a robust phylogenetic tree and large reference data collections. Y‐based ancestry prediction and familial searching can, therefore, provide important investigative leads in crime cases without suspect.This article is categorized under: Forensic Biology > Haploid Markers Forensic Biology > Ancestry Determination using DNA Methods Forensic Biology > DNA Databases and Biometrics Forensic Biology > Forensic DNA Technologies