INTERPOL HANDBOOK ON DNA DATA EXCHANGE AND PRACTICE

GEOGRAPHICAL SEARCH, PHYLOGENY,PHYSICAL CHARACTERISTICSAND OTHER USESThe information in the following section is not linked to the current use of forensicDNA Databases. It represents a future potential use of DNA that does not rely uponcomparison with collected profiles but where the DNA profile itself, obtained throughother genetic markers, may provide investigative support but does not lead to anidentification by itself.The present capacity of forensic DNA technology is impressive; however progressin molecular biology is increasing the range of genetic markers available for forensicpurposes. This has exciting potential for the use of forensic DNA results in investigations.Specific examples of this diversification include more widespread use of Y-chromosomeor mitochondrial DNA (mtDNA) markers (known as non-autosomal markers) or newmarker types such as single nucleotide polymorphisms (SNPs). These target regionsoffer the possibility to produce a DNA profile that indicates information about thebiogeographical ancestry of the donor, or information regarding certain personal orphysical characteristics.•geographic search, phylogenyThe mitochondrial genome and the non-recombining region of the Y chromosomerepresent the only two haploid regions of the human genome as both are transmitteduniparentally, with no recombination 24 . This lack of recombination means that theY chromosome and the mitochondrial variants show greater levels of geographicalaffiliation than profiles obtained through routine autosomal DNA testing.Refining applications for non-autosomal DNA profiling has been of considerable valueto the forensic field as it has increased the investigative relevance of the techniques andadded to the capability of casework laboratories. MtDNA has been extensively usedin human evolution studies for a number of years 25 and is particularly suitable for thisapplication due primarily to the fact it is inherited down the maternal line (from motherto child). In forensic science mtDNA is most often analysed in circumstances whereroutine DNA tests fail to give a result. These commonly include the identification oftelogenic hairs 26 , nail material 27 and bone (associated with missing persons’ cases) 28 . Itis also used in cases where distant relatives are the only available source of referencematerial, such as in historic investigations or cold cases.GEOGRAPHICAL SEARCH, PHYLOGENY, PHYSICAL CHARACTERISTICSAND OTHER USESPAGE 77