title: An investigation of the potential of DIP-STR markers for DNA mixture analyses.
abstract: The genetic characterization of unbalanced mixed stains remains an important area where improvement is imperative. In fact, using the standard tools of forensic DNA profiling (i.e., STR markers), the profile of the minor contributor in mixed DNA stains cannot be successfully detected if its quantitative share of DNA is less than 10% of the mixed trace. This is due to the fact that the major contributor's profile "masks" that of the minor contributor. Besides known remedies to this problem, such as Y-STR analysis, a new compound genetic marker that consists of a Deletion/Insertion Polymorphism (DIP) linked to a Short Tandem Repeat (STR) polymorphism, has recently been developed and proposed. These novel markers are called DIP-STR markers. This paper compares, from a statistical and forensic perspective, the potential usefulness of these novel DIP-STR markers (i) with traditional STR markers in cases of moderately unbalanced mixtures, and (ii) with Y-STR markers in cases of female-male mixtures. This is done through a comparison of the distribution of 100,000 likelihood ratio values obtained using each method on simulated mixtures. This procedure is performed assuming, in turn, the prosecution's and the defence's point of view.
authors.affiliation: University of Lausanne, School of Criminal Justice, Institute of Forensic Science, 1015 Lausanne-Dorigny, Switzerland. Electronic address: giulia.cereda@unil.ch.
authors.forename: G
authors.initials: G
authors.lastname: Cereda
authors.affiliation: University of Lausanne, School of Criminal Justice, Institute of Forensic Science, 1015 Lausanne-Dorigny, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Biedermann
authors.affiliation: University of Lausanne, University Center of Legal Medicine Lausanne and Geneva, Rue du Bugnon 21, 1011 Lausanne, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Hall
authors.affiliation: University of Lausanne, School of Criminal Justice, Institute of Forensic Science, 1015 Lausanne-Dorigny, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Taroni
mesh_terms: D005819:Genetic Markers; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D005819:Genetic Markers
keywords: Deletion/Insertion Polymorphism; Graphical models; Likelihood ratio; Unbalanced DNA mixture