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Intentional Mixed Buccal Cell Reference Sample in a Paternity Case *
Author(s) -
MartinezGonzalez Luis J.,
Lorente Jose A.,
MartinezEspin Esther,
Carlos Alvarez J.,
Lorente Miguel,
Villanueva Enrique,
Budowle Bruce
Publication year - 2007
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/j.1556-4029.2006.00373.x
Subject(s) - buccal swab , saliva , allele , locus (genetics) , sample (material) , genetics , buccal administration , medicine , biology , dentistry , chemistry , chromatography , gene
We report a case where an alleged father (AF) attempted to substitute someone else's saliva sample for his reference sample in a paternity analysis. Buccal cells were collected from the AF and the child, and DNA analysis was performed using an autosomal STR loci (Identifiler ® ). The profile from the AF showed extra peaks in some loci, as well as a much higher “X” allele peak relative to the “Y” allele peak at the amelogenin locus. After conducting reanalysis by another technician with another set of positive and negative controls, it was concluded that the only source of the mixed profile was by intentional introduction by the AF, at the time of sampling, of some foreign human biological material, most likely saliva from a woman. Owing to the inconclusive results, when the AF was called back to the lab and the peculiar results were explained to him, he admitted that he had introduced into his mouth saliva from another person in an attempt to be excluded as the father of the child. Although tampering with DNA reference samples is not common, some individuals may attempt to contaminate or otherwise adulterate specimens before DNA tests. Personnel responsible for sampling should be aware of this possibility and should try to establish procedures to avoid the problem.