Decision analysis for the genotype designation in low-template-DNA profiles

Détails

ID Serval
serval:BIB_10E66487EDF9
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Decision analysis for the genotype designation in low-template-DNA profiles
Périodique
Forensic Science International: Genetics
Auteur(s)
Gittelson S., Biedermann A., Bozza S., Taroni F.
ISSN
1872-6283
ISSN-L
0379-0738
Statut éditorial
Publié
Date de publication
03/2014
Peer-reviewed
Oui
Volume
9
Pages
118-133
Langue
anglais
Résumé
What genotype should the scientist specify for conducting a database search to try to find the source of a low-template-DNA (lt-DNA) trace? When the scientist answers this question, he or she makes a decision. Here, we approach this decision problem from a normative point of view by defining a decision-theoretic framework for answering this question for one locus. This framework combines the probability distribution describing the uncertainty over the trace's donor's possible genotypes with a loss function describing the scientist's preferences concerning false exclusions and false inclusions that may result from the database search. According to this approach, the scientist should choose the genotype designation that minimizes the expected loss. To illustrate the results produced by this approach, we apply it to two hypothetical cases: (1) the case of observing one peak for allele xi on a single electropherogram, and (2) the case of observing one peak for allele xi on one replicate, and a pair of peaks for alleles xi and xj, i ≠ j, on a second replicate. Given that the probabilities of allele drop-out are defined as functions of the observed peak heights, the threshold values marking the turning points when the scientist should switch from one designation to another are derived in terms of the observed peak heights. For each case, sensitivity analyses show the impact of the model's parameters on these threshold values. The results support the conclusion that the procedure should not focus on a single threshold value for making this decision for all alleles, all loci and in all laboratories.
Mots-clé
Low-level-DNA threshold, Bayesian decision theory, Influence diagram
Création de la notice
12/02/2014 8:40
Dernière modification de la notice
20/08/2019 13:38
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