Physical contact can result in the transfer of DNA from one individual to another. In cases of sexual offence this can often be by means of an aggressive or sexual act. Biological material can accumulate under the fingernail hyponychium of both the victim and/or the suspect and has the potential to provide evidence and intelligence information to the police.
The incidence of mixed DNA profiles obtained from fingernail samples of couples who co-habit was explored using AmpFlSTR® SGM Plus® (SGM Plus) (Applied Biosystems®). It was predicted that the higher incidence of contact from co-habitation and therefore the greater opportunity for DNA transfer would result in an increased level of foreign DNA from the partner under the donor's fingernails. Fingernail swabs were taken from all fingers of the left and right hands of 12 couples on three separate occasions.
DNA profiles were compared to both the donor and partner's reference DNA profiles. The number of reportable mixed DNA profiles obtained (17%) was higher than in previous reports. In this study, the majority of non-donor alleles matched the partner's reference DNA profile, indicating that co-habitation affected non-donor DNA obtained from fingernail swabs. The results demonstrated that as the couples spent increasing amounts of time together, the incidence of mixed DNA profiles increased. The large variation in the incidence of foreign alleles observed within and between couples suggested that a combination of lifestyle factors were having a significant effect on whether mixed DNA profiles were observed.
Further DNA profiling using the AmpFlSTR® Y-filer® (Yfiler) PCR amplification (Applied Biosystems) was carried out to determine whether female fingernail samples that had previously given single donor profiles contained low levels of male DNA that may be detected by targeting the Y-chromosome. It was found that 63% of the samples analysed using Yfiler produced full or partial Y-STR profiles. The Y-STR profiles were compared to partners’ profiles and searched through two haplotype databases to determine the evidential value of such samples.
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- Crime in England and Wales 2005/2006. Home Office Statistical Bulletin 12/06.Home Office, London2006
- General profile analysis report on the comparison of sexual offences submitted by the 10 sexual offence service forces to August 2005.Sexual Offence Service. 2005; : 1-49
- PCR-typing of DNA extracted from epidermal particles by scratching.Adv. Forensic Haemogenet. 1996; 6: 316-318
- A 5-year study on DNA recovered from fingernail clippings in homicide cases in Milan.Prog. Forensic Genet. 2003; 9: 929-932
- Genetic analysis of fingernail debris: application to forensic casework.Prog. Forensic Genet. 2003; 9: 921-924
- DNA analysis of fingernail debris using different multiplex systems: a case report.Int. J. Legal Med. 2001; 114: 263-266
- The prevalence of mixed DNA profiles in fingernail samples taken from individuals in the general population.Forensic Sci. Int. Gen. 2007; 1: 62-68
- Prevalence of foreign DNA under the fingernails.in: Proceedings of the Challenges and Changes 17th International Symposium on the Forensic Sciences, Wellington, NZ2004
- Y chromosome haplotype reference database (YHRD): update.Forensic Sci. Int. Gen. 2007; (online June 2007)
- DNA profile match probability calculation: how to allow for population stratification, relatedness, database selection and single bands.Forensic Sci. Int. 1994; 64: 125-140
- The impact of the principles of evidence interpretation on the structure and content of statements.Sci. Justice. 2000; 40: 233-239
- Interpretation of mixtures based on peak area—identification of genetic anomalies, stutters and other artefacts.in: Proceedings of the 2nd European Symposium on Human Identification. 1998: 61-72
- Analysis and interpretation of mixed forensic stains using DNA STR profiling.Forensic Sci. Int. 1998; 91: 55-70
- Persistence of DNA after digital penetration.MSc thesis, Centre for Forensic Science. University of Strathclyde, 2005
- Development and validation of the AmpFlSTR Yfiler PCR amplification kit: a male specific, single amplification 17 Y-STR multiplex system.J. Forensic Sci. 2006; 51: 64-75
- Performance characteristics of commercial Y-STR multiplex systems.J. Forensic Sci. 2007; 52: 1025-1034
- Joint match probabilities for Y chromosomal and autosomal markers.Forensic Sci. Int. 2008; 174: 234-238
Published online: November 05, 2008
Accepted: September 18, 2008
Received in revised form: June 27, 2008
Received: April 23, 2008
☆All work carried out at The Forensic Science Service®.
© 2008 Published by Elsevier Inc.