Likelihood ratio formulae for disputed parentage when the product of conception is trisomic.
We present here the derivation of paternity index formulae that covers situations of a disputed paternity trio with a trisomic product of conception. We consider six possible mechanisms for trisomy to occur: dispermy, dieggy, paternal meiosis I or II, and maternal meiosis I or II in the calculation. We also provide a biological explanation for how each of the mechanisms could give rise to a trisomy. The paper is set out in a general manner so that the tables presented can be used on any instance of trisomic offspring. This work is motivated by a case of disputed paternity where the product of conception was trisomic, i.e. the electropherogram of the product of conception possessed three alleles at each locus. The outcome was extremely strong support for the alleged father's paternity of the product of conception.
Forensic Science South Australia, 21 Divett Place, Adelaide, SA, 5000, Australia. Duncan.Taylor@sa.gov.au.|School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia. Duncan.Taylor@sa.gov.au.
Duncan A
DA
Taylor
Forensic Science South Australia, 21 Divett Place, Adelaide, SA, 5000, Australia.|School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.
Oliva
O
Handt
Forensic Science South Australia, 21 Divett Place, Adelaide, SA, 5000, Australia.|School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.
Damien
D
Abarno
ESR, Private Bag 92021, Auckland, 1142, New Zealand.|National Institute of Standards and Technology, 100 Bureau Drive, MS 8980 and 8314, Gaithersburg, MD, 20899, USA.
John
J
Buckleton
D053803:Forensic Genetics / Q000379:methods; D005838:Genotype; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008540:Meiosis; D010334:Paternity; D011336:Probability; D057885:Triploidy; D014314:Trisomy
Formulae look-up table; Likelihood ratio; Paternity index; Triploidy; Trisomic