Modelling the dependence structure of Y-STR haplotypes using graphical models

Mikkel Meyer Andersen; James Curran; Jacob de Zoete; Duncan Taylor; John Buckleton

doi:10.1016/j.fsigen.2018.07.014

Modelling the dependence structure of Y-STR haplotypes using graphical models

Forensic Sci Int Genet. 2018 Nov:37:29-36. doi: 10.1016/j.fsigen.2018.07.014. Epub 2018 Jul 22.

Authors

Mikkel Meyer Andersen¹, James Curran², Jacob de Zoete³, Duncan Taylor⁴, John Buckleton⁵

Affiliations

¹ Department of Mathematical Sciences, Aalborg University, Skjernvej 4A, DK-9220 Aalborg, Denmark. Electronic address: mikl@math.aau.dk.
² Department of Statistics, University of Auckland, PB 92019 Auckland, New Zealand. Electronic address: j.curran@auckland.ac.nz.
³ School of Electronic Engineering and Computer Science, Queen Mary University of London, 10 Godward Square, London E1 4FZ, England, United Kingdom. Electronic address: jcdezoete@gmail.com.
⁴ School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia. Electronic address: Duncan.Taylor@sa.gov.au.
⁵ ESR, hPB 92021 Auckland, New Zealand. Electronic address: John.Buckleton@esr.cri.nz.

PMID: 30075394
DOI: 10.1016/j.fsigen.2018.07.014

Abstract

Many methods have been suggested for evaluating the evidential value of a matching Y-chromosomal DNA profile obtained from a biological stain associated with a crime scene and the Y-chromosomal DNA profile of a suspect. Most of these methods are based on estimating the population frequency of the Y-profile. The common independence assumption between loci for autosomal DNA profiles cannot be used for Y-chromosomal DNA profiles. In this paper we reconsider the problem of population frequency estimation by application of Bayesian networks and the Chow-Liu algorithm to model dependencies between loci. We found that the method based on the Chow-Liu algorithm performs almost as well as the discrete Laplace method. We have also made comparisons to the independence model and we have demonstrated once again that the independence method for Y-profiles cannot be supported.

Keywords: Chow-Liu algorithm; Discrete Laplace method; Forensic genetics; Lineage markers; Weight of evidence; Y-chromosome.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Algorithms
Chromosomes, Human, Y*
DNA Fingerprinting
Haplotypes*
Humans
Male
Microsatellite Repeats*
Models, Genetic*
Models, Statistical