The Science of Human Genetics and Genetic Testing

Genetic testing and its impacts.

According to the IGCSE Second Edition Biology book, almost every single cell in our body contains genetic information which each carries an identical set of our bodies 50000 to 100000 genes, excluding, the sperm and egg cells that only carries the genes that the father and mother’s offspring would inherit once their sperm and egg fuses together during fertilization.

The genes are stored in the DNA, which is an acronym for deoxyribonucleic acid present in our cells. DNA stores genetic information and determines our biological traits. The structure of DNA looks like a spiral ladder. If unraveled, the DNA contained in each cell would be a meter long. DNA is a long chain of nucleotides, which consists of 4 chemical sub units known as bases. These bases are Adenine, Cytosine, Guanine and Thymine. These bases normally pair with one another and form double-helix structure. In total, the human DNA consists of 3.3 billion base pairs making up 50,000 to 100,000 genes and is called the human genome. In other terms, a genome can be considered a genetic recipe for that person. For example, “genes for eye colour” means that the genes are a code for protein pigments in the iris of our eyes. Genes have different characteristics. However, each of our genes is a copy from either our mother or father. For example, if one of your parents has blue eyes (recessive trait), while the other has a history of brown eyes from their ancestors (dominant trait), you are more likely to inherit the brown eyes. Thus proving that an offspring’s DNA is similar to its parents’ DNA in terms of its molecular structure and genetic code. Because of these similarities, DNA paternity test can be conducted to determine the biological contributors of your traits and inheritance.

The genes are organized into larger units called chromosomes. Thus, proving that genes are located on chromosomes. Each cell has a haploid number of chromosomes, which is 23 derived from the father and 23 from the mother. When the sperm cell from the father and the egg cell from the mother fuse together, an individual with a diploid number of 46 chromosomes is formed.

There are 2 types of chromosomes; autosomal and sex. Autosomal chromosomes are any of the 22 pairs of non-sex chromosomes you see in the diagram above. The 23rd pair of chromosome is the sex chromosome, which determines the gender of an individual. Women usually have 2 “X” chromosomes whereas men normally have one “X” and one “Y” chromosome.

DNA Paternal Testing

Paternity testing is a conclusive way to find out whether or not people are related to each other or in Tom’s case, if Dagg is really his biological father. We are all biologically unique because of DNA. DNA testing is basically a procedure that analyzes DNA to produce DNA profile (4). Because DNA’s are inherited, half from the mother and the other half from the father, DNA testing compares DNA profiles from different people to determine whether or not they really are related to each other.

According to Dr. Oz, this is considered an extremely accurate process that provides the most conclusive analysis of paternity.

DNA paternity testing is increasingly being used for scientific purposes, including settling on crime and investigations, legal disputes or even financial disputes. Determining paternity is also necessary to provide children access to family medical histories and information about potential genetic diseases.

Samples from the respective individuals are collected for the test. DNA can be acquired from blood, cheek cells or other tissue samples. Once the DNA samples are assembled, the genetic markers are then compared to one another.

If Tom were to carry out a paternal test to investigate whether Dagg is his biological father, the following procedure should be carried out.

First, the Tom’s DNA is to be compared to his mother’s DNA. Then, the similar structures and codes matching with his mother’s DNA are detached from the Tom’s DNA sample. The left over segments are then compared to his father’s DNA. If Tom shares similar paternal DNA markers to Dagg, then Dagg us established to be his biological father. However, if the DNA markers are not a match, then it proves that Dagg is not Tom’s father.

DNA Testing Method Technology

There are a few ways DNA testing is carried out today. One of the most common methods of DNA testing is PCR (Polymerase Chain Reaction).

The DNA from a sample such as a mouth swab, blood sample or a swab from a crime scene is extracted and purified. In order to isolates the short turns and repeats, a procedure called PCR (Polymerase Chain Reaction) is carried out on the DNA. PCR copies and amplifies specific target DNA sequences, as shown in Figure 1.

STR (Short Tandem Repeat Polymorphism) is the process of identifying and analyzing the inheritence of a class of DNA. The different lengths of STR’s copied by the PCR reaction are then separated using a process called Electrophoresis. This involves adding the DNA to an Agarose gel and then passing an electron current through it. Because DNA is negatively charged, it would move through the gel to the positive electrode. So, by running an electric current for a certain period of time, the different sized pieces of DNA will spread out through the gel. They can then be revealed using a dye to label them up, producing a line called “band” on the gel. The pattern of these bands showing a presence of different sized repeats is the genetic fingerprint of the person, as described in Figure 2. These days, DNA fingerprinting is used to match suspects to crime scenes or to settle paternity disputes.

The legality of testing another individual’s DNA without their knowledge varies by countries. This is because, different countries around the world have different rules and regulations regarding DNA paternity testing but in most countries, it’s not legal to carry out a DNA paternity test without the knowledge and consent of the individual.

Paternal Testing in United Kingdom compared to Australia

In England, there were no restrictions on paternity tests until the Human Tissue Act in 2004. This is an act of rules and regulations that has implications for good practice of legal paternity testing. If an individual seems to have possessed someone else’s human tissue other than his or her own, such as nail, gametes or hair (in Tom’s case), the Act makes it an offense. Penalties would be provided for not obtaining the consent of that individual.

Similarly, the Australian Law Reform Commission states that agreement from each participant or legal guardian must be obtained in order to do the test. Therefore, in order for Tom to perform paternal testing, both his mother and Dagg must give their written consent to performing the test. However, unlike in the UK where gender is not a concern to perform DNA testing, in Australia it is. The Australian Child Support Agency says men who obtain DNA samples from their children by obeying the court’s guidelines, will not be breaking the law, whereas the situation is not as simple for women. If a women were to perform DNA sampling on her child to find out who its biological father is, she would have to go through several court orders before she could do so.

Besides that, while the questioning of the accuracy, secrecy and interpretation of the test results are generally accepted and common in the UK, there are a number of concerns about its use in Australia, as it is less clear on how the DNA evidence are to be used in Australia. One of the factors affecting this situation is contamination caused by the individual that took the sample, whether the sample has been contaminated or not could affect the whole process of calculating the probability of evidence derived from the DNA test. Thus, showing that Australians are most worried about the interpretation of the DNA samples and the accuracy of the result.

Furthermore, the Human Genetics Society of Australasia states that DNA paternal testing is usually carried out to determine the biological or adoptive parent of a child and not by a stepparent. So, it is used for social and biological context of a child’s rightful guardians. However, if Tom discovers Dagg is not his biological father, Dagg can apply for a court declaration that he is not liable for Tom’s support. This action can simultaneously affect significant implications for Tom’s financial security and sense of identity. However, there are people who do not want to take the test. So, if Tom were to ask the approval of Dagg’s DNA sample to perform paternal testing on, but he refused. Then, court actions would take place.

Ethical Issues

There are a few ethical considerations involved for someone to refuse this test. DNA paternity testing is a procedure with life-changing affects on the individual, in this case Tom to find out whether or not Dagg is really his biological father. It’s also very stressful for the life of Tom and the involvement of his legal guardians in this process. This is why he resulted in committing an illegal act instead by stealing DNA hair samples from Dagg. In certain societies, such as in Asia, this ethic of “genetic services” should be approached more humanistically with love and spirituality instead of regarding it scientifically. They believe that health care providers should form social relationships among their family members rather than in terms of the rights and principles of both parties.

However, the ethical issue in Tom’s situation is “Paternity Fraud”. This is when his father has paid years of Tom’s child support only to find out in the future that another man fathers his son. On the other hand, this would certainly be a serious issue for Tom in terms of his health care and education. For Tom’s biological father, this would disrupt the father-son bond, which is vital in Tom’s psychological and emotional development.

Legal Issues

According to the Department of Health and Human Services report “Paternity Establishment”, when a child is born, its parents must sign a consent form showing parentage through a DNA paternity test to ensure that they are the rightful parent’s of that child. However, most states assume that the parents are provided with an oral notification at the hospital before signing the parental acknowledgment form. For parents unaware of the legal ramifications such a form carries, this can lead to forms being signed without prior knowledge. This in fact, is a violation of the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 that states, “The mother and the father must be given notice orally and in writing, of the alternatives to the legal consequences of and the rights.”

Furthermore, genetic testing is also another form of parental establishment for paternity rights in order to determine the biological father of a child. Most states will only accept DNA tests conducted in a laboratory. This would be a problem for DNA testing labs that are not licensed. Therefore, choosing a licensed, legalized lab ensures that the results are accepted by the state, thus prevents retesting to be done which would be very costly. SPARC states that the average paternity test costs between $450 and $500. The financial aspect of legalized paternal testing would pose an issue to individuals with financial problems.

Moral Issues

There are also some moral concerns over DNA testing’s. And Alec Jeffires (DNA fingerprinting techniques developer) himself believes that DNA testing is no doubtfully a good idea for person or body identifications in emergencies or disasters, but police shouldn’t hold them. Despite the fact that this technique has allowed dangers and violent criminals to be put away, it has exfoliated innocent individuals over the past 25 years. There is lack of support services available to help people who found out that their paternity test was different in compared to the other party. For Tom, finding out Dagg is not his father can leave a devastating affect on him in terms of family breakups and his mental and social well-being of a child without a father, which leads to the emotional impacts of paternal testing.

Emotional Issues

No matter what, questions on “who is my father?” are an inevitable roller coaster of emotions and turmoil’s. Paternity issues can leave a child pondering on questions regarding parenthood, which can lead to a low self-esteem, confusion and the fear of rejection. A child, such as Tom pins his hopes on paternity test to reveal an idealistic mental figure of his biological father. If proven false, the reality can leave him devastated. Besides the emotional impact on the child, DNA paternity tests can also be hurtful to the father/step father, who could feel betrayed, hurt and furious. It’s also worth remembering that even though DNA paternity test could prove whom the biological father is, it doesn’t always mean that he would want to meet the child. Therefore, it would have been better if Tom had discussed about DNA paternity test with his mother in great depth first before undertaking it.

Conclusion

I think that paternity testing should be a mandatory and standard practice instead of a legal, testimonial, scientific procedure. This is because when a child is born into this world, its gender and blood type is determined, but not who their biological father is. I believe a child has the right to know its genetic history. Consider Tom’s story as an example. He had to steal DNA hair samples from Dagg in order to perform a paternity test. This is an illegal act only if it is misused. This is why in order to determine who the biological father is, Tom would need to go thorugh prcodeurrs and governmental supervison. if its not done, its considered illegal, depending on the law.

However, if I was Dagg and a boy wants a paternity test to prove I’m his father through science, I would feel devastated. What if I was his real father, I don’t think I would let him in my life again. As painful as this may sound, I think paternity tests will save kids like Tom from pondering on who their real parent is, and saves the mother and child from the feelings and emotions of doubt, as paternity tests provides them the chance to look for the real father.