DNA Profiling and Ethics Reflection Journal Vanshika Khemka 14th October 2012 “33 autorad off” On 10th September 1984, geneticist Alec Jeffrey’s wrote these three words in his red desk diary. This marked the completion of an experiment, which studied how inherited illnesses pass through families. The experiment failed entirely. (McKie, 2009) However, this led to the most profound discovery: the world’s first DNA fingerprint. Now, the smallest swab of blood or sweat can determine the identity of an individual.
We will discuss this process of DNA profiling in this journal. After going into the in-depth analysis of DNA profiling, we will discuss its uses and the ethical and legal issues that swarm the subject. |What is DNA Profiling? | Formally, DNA profiling is the analysis of short, highly specific, tandem-repeated- or hypervariable- genomic sequences, minisatellites known as variable number of tandem repeats (VNTRs), to detect the degree of relatedness to another sequence of oligonucleotides. Segan, 1992) It is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles, which are encrypted sets of numbers that reflect a person’s DNA makeup and can also be used as the person’s identifier. |The Process | Deoxyribonucleic Acid (“DNA”) is a six-foot long molecule found in the nucleus of every cell in the body. With the exception of identical twins, each individual’s DNA is unique.
Thus the first step in the profiling process is to obtain a sample of the individual’s DNA, which is usually done using a buccal swab (i. e. from the cheek). We could also use a sample of blood, semen or hair. This sample is then analyzed using different techniques; discussed below. |Techniques of DNA Profiling | |Restriction Fragment Length Polymorphism (RFLP) |
It is a technique that exploits variations in homologous DNA sequences. It refers to a difference between samples of homologous DNA molecules that come from differing locations of restriction enzyme sites, and to a related laboratory technique by which these segments can be illustrated. In this process, the DNA is first chemically extracted from the sample. It is then fragmented using restriction enzymes. These enzymes act like scissors and cut the DNA where a specific sequence occurs.
By gel electrophoresis, the DNA fragments are placed in a gel through which an electric current is passed. Owing to the negative charge of the DNA, the fragments migrate toward the positively charged pole of the gel. The DNA is then denatured and Southern blotting transfers the DNA fragments to a nylon membrane. A buffer solution is pulled through the gel and membrane and absorbed in paper towels. Hybridization, brought about by radioactive probe, shows only those fragments of interest from the polymorphic area of the DNA.
Autoradiography is carried out next where the blot is placed in contact with a piece of x-ray film, where the radioactivity probe exposes the film and bands appear on the film where the probe has bound to the DNA. The results are then interpreted and in the case of a criminal investigation or civil case, it is matched against the suspect’s DNA profile, thus completing the process. (Hoeffel, 1990) This method is however very long-winded, cumbersome and the combination of all the above-mentioned steps could take about a month to complete.
A large sample is required which makes it tougher. Hence other methods are adopted in recent times. |Polymerase Chain Reaction | With the invention of the polymerase chain reaction (PCR) technique, DNA profiling took huge strides forward in both discriminating power and the ability to recover information from very small (or degraded) starting samples. PCR greatly amplifies the amounts of a specific region of DNA.
This process increases the number of copies of the allele, making enough DNA to allow the test to be performed on what may have originally been a DNA sample of insufficient molecular weight. Due to this technique the test can be conducted using a single hair strand. (Hoeffel, 1990) This process consists of a series of 20-40 repeated temperature changes, called cycles, with each cycle commonly consisting of 2-3 discrete temperature steps. The cycling is often preceded by a single temperature step (called hold) at a high temperature (>90°C), and followed by one hold at the end for final product extension or brief storage.
The temperatures used and the length of time they are applied in each cycle depend on a variety of parameters. These include the enzyme used for DNA synthesis, the concentration of divalent ions and dNTPs in the reaction, and the melting temperature (Tm) of the primers. The rest of the process is similar to the RFLP method. The major breakthrough is the fact that now the smallest trace of evidence can be used for DNA profiling as opposed to the large samples needed in the RFLP method. |Short Tandem Repeat Analysis |
Also known as Microsatellites, short tandem repeats is used as an extension of the PCR Method. This method uses highly polymorphic regions that have short repeated sequences of DNA (the most common is 4 bases repeated, but there are other lengths in use, including 3 and 5 bases). (Hoeffel, 1990) Because unrelated people almost certainly have different numbers of repeat units, STRs can be used to discriminate between unrelated individuals. These STR loci (locations on a chromosome) are targeted with sequence-specific primers and amplified using PCR.
The DNA fragments that result are then separated and detected using electrophoresis. |Amplified Fragment Length Polymorphism | This is another technique that is much faster than RFLP and uses PCR. It not only has higher reproducibility, resolution, and sensitivity at the whole genome level compared to other techniques, but it also has the capability to amplify between 50 and 100 fragments at one time. In addition, no prior sequence information is needed for amplification (Meudt & Clarke 2007).
As a result, AFLP has become extremely beneficial in the study of bacteria, fungi, and plants, where much is still unknown about the genomic makeup of various organisms. |Applications of DNA Profiling | DNA profiling is extensively used for paternity testing and forensic analysis for criminal investigations. Parental testing is the use of genetic fingerprinting to determine whether two individuals have a biological parent–child relationship.
Comparing the DNA sequence of an individual to that of another individual can show whether one of them was derived from the other. Specific sequences are usually looked at to see whether they were copied verbatim from one of the individual’s genome to the other. (Berry, 1991) As for forensic analysis, laboratories compare the molecular weights of fragments of DNA from the suspect sample and crime sample and decide whether the two fragments could have come from the same individual. There are major benefits from this technology: the potential to make speedy and robust suspected offender identi? ations through automated profile comparisons in centralized criminal justice databases; the ability to con? dently eliminate innocent suspects from investigations; the increased likelihood of generating reliable and persuasive evidence for use in court; a reduction in the cost of many investigations; the likely deterrent effect of DNA databasing on potential criminal offenders; and a possible increase in public con? dence in policing and in the wider judicial process. (Berry, 1991) We will explore the ramifications of this extensive use in the next section. Is it ethical? | Now that we know the widespread use of DNA profiling, we see the power that it has and the influence it can have when it comes to people’s lives and the verdict issued in criminal cases. But is this power justified on an ethical front? Is it ethical to give so much power into the hands of the people responsible for carrying out these tests? Indeed, the development and application of DNA pro? ling has been widely described as the “greatest breakthrough in forensic science since ? ngerprinting. ” However, the spread of forensic DNA pro? ing and databasing has also prompted a wide range of concerns about problems that may arise from the storage of tissue samples (especially those taken from individuals without consent) and the proliferating uses of genetic information by the police. (Williams & Johnson, 2006) One could say that DNA profiling violates basic ethical values. Based on the values of liberty, our rights are technically reduced by police powers, which have the right to take and retain fingerprints and DNA profiles and samples without consent. The Forensic Use of Bioinformation: Ethical Issues, 2007) “So act that you use humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means”; these words of wisdom imparted by Kant, also suggest that DNA profiling and the freedom to use that as evidence without explicit permission of the individual concerned would be using them as a means to an end and not an end in themselves. Therefore it can be argued that using DNA profiling takes away autonomy. The Forensic Use of Bioinformation: Ethical Issues, 2007) Spatial privacy is “a state of non-access to the individual’s physical or psychological self”. This is invaded by the nonconsensual taking of biological samples and fingerprints, and, to a lesser extent, by unwanted surveillance of the individual. And as can be inferred by the very nature of DNA profiling, informational privacy and anonymity is infringed upon by using samples obtained from databases and tests. (The Forensic Use of Bioinformation: Ethical Issues, 2007)
Additional issues arise if identifiable samples or profiles on a forensic database are used for research outside the narrow context of identification and police investigations. Using DNA profiling for paternity testing and for determining one’s lineage can be very harmful as it violates the privacy of the people concerned. It could cause potential moral and mental harm to the parents and the children concerned as entire families can be uprooted as a result of this. Past criminal cases which used paternity testing also prove that relatives and families can be affected mentally as well as physically.
People in witness protection programs as well as people on the police databases can be negatively affected if a previously unknown family link is reestablished without their knowledge and consent. (Haimes, 2006) The list of legal and ethical concerns is endless. The question the arises that which side wins? Benefits of DNA profiling, or the issues concerning DNA profiling? |Which side is stronger? | Having seen the costs and benefits of DNA profiling and its usage, the benefits are debatable on moral and ethical grounds.
However, in my personal opinion, it does not have to be black and white; good or bad. There can be a grey area, a middle ground, where DNA profiling is neither entirely correct nor entirely wrong. There have been cases where DNA evidence has saved many innocent lives and incriminated people who had been causing immense harm to others. Thus, we should pass legislations, which aim at curbing violations and encouraging true and just practices. In the cases where the DNA of individuals is being used as evidence or if parental testing is being done, their should be informed consent by the individuals.
They should be aware of the sensitive nature of the information and should be expressly asked for consent to have the data published or used as evidence. The National DNA Database set up in the UK is an example of the dangers and benefits DNA profiling can hold. Personally, a national DNA database in all countries would be a very risky venture as a lot of personal information would be at stake and inter country rivalries could result. We have established the power of DNA profiling and the power that people who have access to this information have. So I would like to end with a quote.
One’s interpretation of this quote can determine where they stand on the matter. “It is time for you to gather some idea of what power means. The first thing you must realize is that power is collective. The individual has power in so far as he ceases to be an individual… The second thing for you to realize is that power is power over human beings. Over the body- but, above all, over the mind. Power over matter- external reality, as you would call it- is not important. Already our control over matter is absolute. ” – George Orwell, Nineteen Eighty-Four Bibliography | Berry, D. A. (1991). Inferences Using DNA Profiling in Forensic Identification and Paternity Cases. Statistical Science , 6 (2), pp. 175-205. Haimes, E. (2006, June 1). Social and Ethical Issues in the Use of Familial Searching in Forensic Investigations: Insight from Family and Kinship Studies. Journal of Law, Medicine and Ethics , 263-276. Hoeffel, J. C. (1990, January). The Dar Side of DNA Profiling: Unreliable Scientific Evidence Meets the Criminal Defendant. Stanford Law Review , 42 (2), pp. 465-538.
McKie, R. (2009, May 24). Eureka moment that led to the discovery of DNA fingerprinting. Retrieved October 10, 2012, from The Guardian: http://www. guardian. co. uk/science/2009/may/24/dna-fingerprinting-alec-jeffreys Segan, C. J. (1992, February 15). DNA Profiling. The Dictionary of Modern Medicine . The Forensic Use of Bioinformation: Ethical Issues. (2007, September). NuField Council on Bioethics . Williams, R. , & Johnson, P. (2006, June 1). Inclusiveness, Effectiveness and Intrusiveness: Issues in the Developing Uses of DNA Pro? ling in Support of Criminal Investigations. Journal of Law, Medicine and Ethics , 234-247. Wikipedia