Introduction to Forensic Genetics

Dr Will Goodwin, Senior Lecturer in Forensic Genetics, Faculty of Science and Technology, University of Central Lancashire.Dr Sibte Hadi, Senior Lecturer in Forensic Genetics, Faculty of Science and Technology, University of Central Lancashire.Dr Adrian M. T. Linacre, Department of Pure and Applied Chemistry, University of Strathclyde.

• Foreword ixPreface xiPreface to first edition xiii1 Introduction to forensic genetics 1Forensic genetics 1A brief history of forensic genetics 2References 62 DNA structure and the genome 11DNA structure 11Organization of DNA into chromosomes 11The structure of the human genome 13Genetic diversity of modern humans 15The genome and forensic genetics 16Tandem repeats 16Single nucleotide polymorphisms 18References 193 Biological material – collection, characterization and storage 21Sources of biological evidence 21Collection and handling of material at the crime scene 23Identification and characterization of biological evidence 23Evidence collection 29Sexual and physical assault 31Storage of biological material 32References 324 DNA extraction and quantification 37DNA extraction 37General principles of DNA extraction 37DNA extraction from challenging samples 41Quantification of DNA 45DNA IQ system 48References 495 Polymerase chain reaction 53The evolution of PCR-based profiling in forensic genetics 53DNA replication: the basis of the PCR 54The components of PCR 54Taq DNA polymerase 54The PCR process 56PCR inhibition 58Sensitivity and contamination 60The PCR laboratory 60Further reading 62References 626 The analysis of short tandem repeats 67Structure of STR loci 67The development of STR multiplexes 67Detection of STR polymorphisms 70Interpretation of STR profiles 72Further reading 77References 777 Assessment of STR profiles 81Stutter peaks 81Split peaks (±N) 81Pull-up 83Template DNA 84Overloaded profiles 84Low template DNA typing 84Peak balance 86Mixtures 86Degraded DNA 88PCR inhibition 90References 918 Statistical interpretation of STR profiles 95Population genetics 95Deviation from the Hardy–Weinberg equilibrium 96Statistical tests to determine deviation from the Hardy–Weinberg equilibrium 97Estimating the frequencies of STR profiles 98Corrections to allele frequency databases 98Which population frequency database should be used? 103Conclusions 104Further reading 104References 1049 Evaluation and presentation of DNA evidence 107Hierarchies of propositions 107Likelihood ratios 109Two fallacies 113Comparison of three approaches 114Further reading 115References 11510 Databases of DNA profiles 117The UK National DNA Database 117International situation 124Further reading 128References 12811 Kinship testing 131Parentage testing 131Punnett square 132Identification of human remains 139Further reading 140References 14012 Single nucleotide polymorphisms 145SNPs – occurrence and structure 145Detection of SNPs 146SNP detection for forensic applications 148Forensic applications of SNPs 149SNPs compared with STR loci 150References 15213 Lineage markers 155Mitochondria 155Applications of mtDNA profiling 157Haplotypes and haplogroups 159The Y chromosome 161Forensic applications of Y chromosome polymorphisms 162Further reading 165References 16514 Non-human DNA typing 171Non-human sample types 171Species identification 173Linkage to an individual using STR loci 174Linkage to an individual using mitochondrial loci 175Microbial DNA testing 176Concluding comments 176Further reading 176References 176Appendix A Forensic parameters 181Appendix B Useful web links 183Glossary 185Abbreviations 189Index 193