DNA Profiling and the Related Ethical and Personal Issues - Research Paper Example

DNA, the blueprint for any living life, is having applications in many ‘spheres’ of human lives. It plays a key role in the ‘birth’ of human lives and that role even extends after death. DNA’s role after death is mainly to find out the nature and cause of death and this where DNA profiling comes into the picture. DNA profiling, also known as DNA typing or even genetic fingerprinting, is a technique followed by forensic scientists to assist them in identifying individuals based on their respective DNA makeup or profiles. “As all living things contain DNA, and all DNA exhibits variability both among and within species, any biological material associated with a legal case carries in it information about its source.” (Jobling and Gill, 2004). Although, human DNA sequences shows 99.9% similarity in every person, that 0.1% variations in any individual’s DNA makeup or profile also known as Short Tandem Repeats (STRs) is only utilized by the forensic scientists as part of DNA profiling. “Each human cell contains three billion DNA base pairs. Our unique DNA, 0.1 percent of 3 billion, amounts to 3 million base pairs. This is more than enough to provide profiles that accurately identify a person.” (Wittmeyer). Evolution of DNA profiling in predicting the physical characteristics DNA profiling technique was first developed by Sir Alec Jeffreys in 1983, and its application in Forensic science began immediately with U.S. courtrooms accepting DNA based evidences from 1987. The next step was the introduction of polymerase chain reaction (PCR), which allowed the analysis and development of DNA profiles retrieved from minute quantities of biological content. The Autosomal short tandem repeats (STR) became the key driver in DNA profiling and is continuing its role even now. Another major advancement in DNA profiling is the use of mitochondrial DNA to retrieve needed information from old specimens of bones and teeth. From those beginnings, DNA profiling systems has seen significant advances, with identification taken to optimum levels in the form of predicting or identifying the physical characteristics of individuals specifically suspects based on DNA materials, thereby even creating a visual image. This concept of developing or generating a physical ‘picture’ of an individual from their own DNA is known as “Molecular Photofitting” in some Forensic circles. Although, a lot of scientific researches are going on and even new technologies and processes are developed, this concept without apt legislation is not widely accepted within the legal framework. Apart from scientific shortfalls, ethical and personal issues like violation of privacy also prevent this new technology or innovation from being fully incorporated into DNA profiling as well as Forensic science. In most countries, DNA based prediction of physical traits might be considered a violation of privacy, with Netherlands being the only country that has legally permitted the use of the molecular photofitting concept in criminal investigation. (Mertens, 2009). Although, from Forensic science perspective, the concept of “Molecular Photofitting” with the ability to develop a “visual picture” of a suspect based only on DNA is not fully developed and is yet to get legal acceptance, recent developments in DNA profiling on same lines as Molecular photofitting helps the forensic geneticist to get an idea about the various physical characteristics of the suspect. “Whilst it won’t be as exact as a photo, they will be able to determine height, skin colour, hair colour and general facial features, even when there are no eye witnesses to help.” (bond.edu.au) Different from Conventional DNA profiling Conventional DNA profiling in forensics till now can only be used to identify individuals, who is an alleged suspect or featured in the databases like CODIS, as the approach is mainly comparative. However, when the DNA profile obtained from the evidence material does not match any of the known suspects tested, nor anybody in the criminal DNA database, then, appearance information estimated or generated from evidence material could help in finding those unknown persons or suspects. (sciencedaily.com, 2010). The first step in that direction was the introduction of Y chromosomal STRs, which helped in differentiating between male and female DNA, the key factor in identify the physical characteristics. In forensics, this helps the resolution of sexual assault cases, discriminating between the (female) victim’s own DNA profile and the one from the assailant. (Mertens, 2009). In addition, the sex marker amelogenin can be considered as first valid marker for a physical trait, as it can clearly distinguish between the sexes of the suspect, but it will only be minor information in the context of the case. “The crime stain's DNA profile itself provides limited information to investigators, with gender being all that can currently be deduced” (Mertens, 2009). Role of single nucleotide polymorphisms (SNPs) The basic fact is, although some are impacted by environment, sizable numbers of physical characteristics are significantly determined by genetic makeup, through a particular combination of DNA. These include major phenotypic or physical descriptors like color, height and other facial features. All these phenotypic traits are caused by number of polymorphisms that occurs in a number of genes, particularly single nucleotide polymorphisms (SNPs) found in a variety of genes and intergenic regions that act together in specific combinations. (van Daal, Manoharan and Ni). Scientists are now investigating with clear direction and hope that single nucleotide polymorphisms (SNPs) has the potential to aid in the physical description of an alleged suspect. The first key physical descriptor can be the pigmentation based ethnicity or race, for which some SNPs can be used as ancestry informative markers (AIMs). That is, set of SNPs are studied regarding their potential to predict color of hair, eye as well as skin. When this role of SNPs is viewed critically, it is clear that their role can be limited by certain external environmental factors, and this may work as an impediment for the forensic scientists. “One limitation of these tests is that environmental and nutritional conditions can complicate final phenotype determination. Plus, phenotypes can be masked: Someone can have grey hair or shave their head (or be naturally bald).” (van Daal, Manoharan and Ni) SNPs role in inferring geographic region of the suspect and the recent developments In cases of unknown criminals and suspects, after finding out about their sex using DNA, their geographic region or even race inference using DNA materials can give good inputs for the investigating agencies to move forward. To identify the ethnicity or race, recent developments based on SNPs particularly regarding AIM can play a key role. “Recently, it has been demonstrated that an individual’s geographic ancestries can be inferred from genetic markers, called ancestry-informative markers (AIM).” (Mertens, 2009). Many research groups all over the world are developing SNP assays which can aid in cornering the ethnicity of individuals, based only on their DNA. Phillips and his group of researchers have developed a single tube 34-plex SNP assay for assignment of ethnicity based origins by particularly selecting AIMs, which showed highly contrasting allele frequency distributions between European, Sub-Sahara African and East Asian population groups. (Mertens, 2009). Based on this, they developed a classification algorithm based on maximum likelihood using a database of 360 individuals, sampled from two populations each from the major population groups. (Mertens, 2009). These developments in determining the ethnicity or geographic origin of the alleged suspect based on their DNA recovered from the crime scene can provide some direction for the investigators. “It might narrow the pool of suspects, could be instrumental when eye witnesses are unavailable and could help for identification of corpses.” (Mertens, 2009). However, there are some limitations in just getting an idea about their geographic region, without any information about their particular ethnicities or countries. “We may not be able to tell German from French, but we can place individuals in major continental groups." (Snyder-Sachs, 2003) Recent developments in determining the pigmentation Pigmentation is a key physical trait, which can give more clear information about the physical appearance of any individual, as they contribute color not only to skin, but to other parts as well. “To date most work in this area has concentrated on pigmentation, since the genetic basis of hair, skin and eye colour is quite well understood.” (van Daal, Manoharan and Ni). The recent developments mainly focus on studying the role of melanocortin-1 receptor (MC1R) in determining the pigmentation of various parts. MC1R is primarily located within the melanocyte cell membranes, and when binding of α-melanocyte stimulating factor to MC1R occurs, it increases the synthesis of black and brown pigments (melanin and eumelanin). (van Daal, Manoharan and Ni). In addition, mutations in this MC1R gene can interfere with the production of melanin and eumelanin, thereby leading to the predomination of red and yellow pigments (pheomelanin). Researchers have ‘cornered in’ about 30 known MC1R variants, which are shown to be associated with red hair, fair skin and freckling. So, it is clear that these developments can aid the forensic geneticists a lot in determining the suspect’s skin color, hair color and even eye color. “A genetic test to detect these variants is already being used in the United Kingdom as an investigative tool.” (van Daal, Manoharan and Ni). Recent developments to determine human age Another key physical characteristic which can aid the investigators is the age of the suspect. Currently, developments have taken place to determine the age from only bloodstain, even if it is in dried form. That is, till now age estimation based on DNA found in the crime scene had limited possibilities, because earlier methods can determine age using only bones, teeth and other identifiable physical parts. As, it is not possible to find these body parts in all crime scenes, it became a difficult exercise. However, blood of the suspect can be found in a more common manner, when compare to these parts, and this ‘opportunity’ was only used to come with a assay, that can determine the age from the bloodstain. “We demonstrate that human age can be estimated from blood with reasonable accuracy using a simple, robust, and sensitive test assay," said Manfred Kayser of the Erasmus MC University Medical Center Rotterdam in the Netherlands.” (sciencedaily.com, 2010). This test aptly utilizes the particular characteristic of T cells, an immune system cell, which first recognises any micro organisms and in that process of recognising undergoes particular rearrangement. As a by-product of that process, T cells will contain tiny loops of DNA known as 'single joint TCR excision circles', or sj TRECS for short, and these sj TRECS declines at a constant rate with age, aiding in determination of the age. That is, the test assay will count the number of sj TRECS in a small blood evidence retrieved from the crime scene, and then compares them with other extracts of DNA in the same blood evidence that are not affected by age. As this test allows age estimation in the range of plus or minus nine years, it can give the forensic geneticists and investigations a good input in solving the case. Ethical and personal issues Apart from the scientific limitations that were discussed throughout the paper, there are also certain ethical and personal issues, which have to be considered regarding this new scientific and technological development. That is, according to some critics, the DNA profiling can be done only if it is of utmost necessity for investigations, and any profiling which reveals other aspects should not be made public. So, the key factor here is the information, the DNA based forensic phenotyping reveal. “Koops and Schellekens argued in a recent review (12) that the degree to which forensic phenotyping should be allowed depends on the sensitivity of the information revealed.” (Sundquist, 2010). That is, apart from providing details about the physical appearance, if the DNA profiling analysis and even reveals sensitive information like the individual’s ancestral genetic information, information regarding he/she is susceptible towards some diseases, etc, etc. If this sort of information is revealed, it could affect them psychologically, leading to both personal as well as ethical issues. For example, a suspect could suffer an identity crisis if an AIM analysis predicts that he has ancestors of an ethnic group against which he is prejudice. (Sundquist, 2010). So, the ethical issue here is, if a group of suspects from a single group are singled out and discriminated in the public solely based on their DNA profile, it will lead to prejudices in the public against members of such groups (Kaysera and Schneiderb 2009). So, apt legislations have to be brought in to prevent any revealing of results of DNA profiling, until the suspect is proven guilty. In addition, the complexity of these quantitative traits, along with variability caused by environmental and nutritional differences, means that even if the genes influencing them were identified, there is no guarantee that simple deterministic tests would emerge, necessitating the need for the development of advanced tests. (Jobling and Gill, 2004). Conclusion From the above analysis, it is clear that recent developments in the field of DNA profiling particularly regarding the genetics of phenotypic traits can aid the forensic geneticists to predict the physical characteristic of a suspect based only DNA evidence found in the crime scene. So, it is akin to creating a photo or visual image of the suspect or like providing a kind of eyewitness identification. These recent developments are seen as harbingers of more advancement, which can aid the investigators to find out all wrongdoers and which would not allow any of them to go scot-free, thus solving more crimes and minimizing the crime rate in the society. References bond.edu.au. Picture Perfect DNA. Retrieved on December 7, 2010 from http://www.bond.edu.au/faculties-colleges/faculty-of-health-sciences-and-medicine/research/research-projects/dna-profiling/index.htm Jobling, MA and Gill, P. (2004). Encoded evidence: DNA in forensic analysis. Nature Reviews Genetics 5: 739-751. Kaysera, M and Schneiderb, P. M. (2009). DNA-based prediction of human externally visible characteristics in forensics: Motivations, scientific challenges, and ethical considerations. Forensic Science International: Genetics 3 (2009) 1-161 Mertens, G. (2009). Forensic DNA Typing: Quo Vadis? The Open Forensic Science Journal, 2: 21-28 sciencedaily.com. (2010). Age Estimation from Blood Has Immediate Forensic Application. Retrieved on December 7, 2010 from http://www.sciencedaily.com/releases/2010/11/101122121629.htm Snyder-Sachs, J. (2003). DNA and a new kind of racial profiling. Popular Science, 263 (6). Sundquist, T. (2010). Forensic Phenotyping: What DNA Can (and Cannot) Tell Us About a Criminal’s Appearance. Retrieved on December 7, 2010 from http://promega.wordpress.com/2010/04/26/forensic-phenotyping-what-dna-can-and- cannot-tell-us-about-a-criminal%E2%80%99s-appearance/ van Daal, A., Manoharan, S and Ni, M. DNA Idenitikit: Use of DNA Polymorphisms to Predict Offender Appearance. Retrieved on December 7, 2010 from http://www.promega.com/geneticidproc/ussymp18proc/oralpresentations/vanDaal.pdf. Wittmeyer, J. CAN DNA DEMAND A VERDICT? Retrieved on December 7, 2010 from http://learn.genetics.utah.edu/content/labs/gel/forensics/ Read More