Chapter 2 Controversial Issues in Gene Research

 

by Donna M. Brinton, Christine Holten, and Jodi L. Nooyen

Background | Classroom Applications | Internet Resources | Appendices

Background

Scientists have recently completed a preliminary “map” of all the genes in the human body. This is also known as the Human Genome Project and consists of all the sequences of DNA chemical units that tell a cell how to behave. This accomplishment has incredible benefits. However, it also raises new, complex issues that society cannot ignore.

This chapter explores the following questions:

• What practical results has the Human Genome Project had?
  
  
• How do these scientific advances benefit us?
  
  
• What potential disadvantages do they have for individuals and society?
  

The chapter gives an overview of the technologies that have been developed as a direct result of DNA and genetic research. It also gives students the chance to debate the ethical questions surrounding this technology.

Background Information

Reflecting on the ethical challenges created by genetic research findings, former U.S. President Bill Clinton said, “As we consider how to use new discoveries, we must also not retreat from our oldest and most cherished values.... Increasing knowledge of the human genome must never change the basic belief on which our ethics, our government, our society are founded. All of us are created equal, entitled to equal treatment under the law.” British Prime Minister Tony Blair also discussed the need to use this new technology responsibly: “We cannot resist change, but our job—indeed, our duty—is to make sense of change, to help people through it, to seize the massive opportunities for better health and better quality of life and then, with equal vigor, to minimize the threats such developments pose.”

DNA testing: Advantages and Disadvantages

The ongoing project to map the human genome affects all of us in several key areas. The first is DNA testing. This subfield of gene research uses tiny human tissue samples of 100–200 cells (for example, blood, hair, saliva) to identify DNA patterns. These samples are used to establish a person’s identity, for example, in (1) tests for blood relationships such as parenthood, (2) identification of criminals (rapists, murderers), and (3) proving the innocence of people falsely accused of a crime. In this testing, the DNA pattern of a person’s hair, blood or saliva is matched with a similar DNA sample from a second person. For example, when establishing parenthood, DNA from the mother or father is matched with DNA from the fetus or child. When identifying criminals, DNA samples from the crime scene are matched with a suspect’s DNA.

Some benefits of DNA testing are clear and unquestioned. It is a key tool in the criminal justice system, helping courts to discover whether a person suspected of committing a crime is guilty or innocent and helping police to find criminals. It has even been used to prove the innocence of criminals on death row many years after a crime was committed. In addition, it is replacing genealogy and family trees as a method for determining ancestry. A famous case is the link that was established between the children of Sally Hemmings, a black slave, and U.S. President Thomas Jefferson. Finally, this test has also been used to establish the identity of dead bodies. One example of this occurred several years ago when a body was removed from the Tomb of the Unknown Soldier in Washington D.C. and the identity of that soldier was determined.

In most cases, DNA testing has been beneficial. However, for those who wish to hide their identity (such as fathers who do not want to take financial responsibility for their children), it has unwanted consequences. For families researching their background, it is much more reliable and less time-consuming than constructing the genealogy of a person. However, it can also reveal things that they do not want to know, forever changing a person’s concept of family and self. Furthermore, DNA testing has become a business. Even funeral homes and burial services now offer to save DNA samples (e.g., hair, blood) for a fee. This raises questions of both privacy and ethics. What are the rights of the dead person? Who has access to these samples? How and where should they be stored? What happens to the samples if the storage company goes bankrupt?

Genetic Testing for Diseases: Advantages and Disadvantages

Genetic testing for diseases is also a significant part of our lives now. The sequencing of the human genome has made it possible to identify and link genes to diseases such as Tay-Sachs, diabetes, breast cancer, and even obesity. As these genes are identified, tests are also developed to detect their presence in human tissue samples. This technology is being put to use in several ways. It allows parents to identify the genetic features of a baby before it is born, young adults to determine whether they have inherited the genes for a particular disease, and scientists to create computer data banks that contain information from genetic testing.

Below is a list of diseases that may be caused by damaged genes and an explanation of these diseases.

Disease	Effects	End Results
Tay-Sachs	damage to the nervous system	affects children; incurable
Alzheimer’s	loss of memory	affects older people; incurable
diabetes	imbalance in an individual’s blood sugar. If it is not controlled, it can damage an individual’s eyes, kidney’s and other organs.	one type begins in childhood; a second type begins in adulthood; controllable with medication
Huntington’s	a degenerative brain disorder. It slowly diminishes an individual’s ability to walk, think, talk and reason.	affects people aged thirty to forty; incurable
Lou Gehrig’s or ALS	affects and eventually destroys an individual’s voluntary muscle action. Patients in the later stages of the disease become totally paralyzed.	Affects middle aged adults; incurable
Multiple sclerosis	slowly destroys the central nervous system	affects people in their 20s and 30s; often results in paralysis and death, although not everyone with the disease dies.
Sickle Cell Anemia	misformed red blood cells cause pain, damage, low blood count, and anemia. It can damage major organs such as kidneys and eyes.	afflicts certain ethnic groups; may lead to death
Breast cancer	malignant cells in the breast	affects women; can be controlled with surgery and drugs, but may lead to death
Colon cancer	malignant cells found in the colon or rectum	affects men and women; can cause death
Ovarian cancer	malignant cells found in women’s reproductive organs	affects women; usually leads to death

 

Although this area of research appears to be similar to DNA testing, it has more potential disadvantages. While genetic testing allows parents to determine if their unborn baby will suffer from any life-threatening illnesses or profound mental defects, it also brings with it the possibility that parents might try to create “designer babies.” Genetic testing gives adults access to information about inherited diseases that can be successfully controlled or treated through changes in lifestyle or medication. However, if the disease is incurable and devastating (for example, Alzheimer’s, Huntington’s, Lou Gehrig’s disease), living with this knowledge may be more of a curse than a blessing. It may affect people’s decisions about whether to have children or to get married. In short, it may change their lives completely. In extreme cases, it may even lead them to consider or attempt suicide.

We may have too much faith in genetic testing. Because of these tests, we tend to believe that our genetic inheritance is our destiny. However, the tests themselves are problematic in several ways. First, they are not always 100 percent accurate. The technology is still relatively new and the results of genetic tests, like any other medical tests, can be misinterpreted. Second, even if a test shows that an individual carries the gene for a disease, this does not necessarily mean that he or she will get the disease. Other factors such as lifestyle, diet, and even the environment may have more effect upon a person’s health than the presence of the gene. Thus, while information from genetic testing may provide important clues about our health, it should not change the way that we define ourselves.

In addition to these practical and ethical concerns about genetic testing, this technology may threaten a person’s right to privacy. Since the information from genetic testing is stored in a computer, it can be accessed—both by those who have legal right to see it (for example, a doctor) and those who do not (an employer). An important concern here is that insurance companies, employers, and the media might find information and use it against an individual, for example, to deny them insurance coverage or to fire them from a job. Similarly, in an election campaign, the media might reveal medical information about a candidate that would seriously hurt his or her chances of being elected.

Benefits and Dangers of Gene Therapy

In addition to genetic testing, which detects diseases, scientists are beginning to develop therapies to treat diseases that have a genetic origin. This therapy works in two ways. In the first, gene transfer, researchers replace “bad” DNA with “good” DNA. In the second, gene repair, researchers block or stop the action of a harmful gene. These therapies are still highly experimental, and there have been numerous side effects during testing such as fevers, abnormal blood clotting, partial paralysis, and even death. One extreme instance of such problems happened with Jessie Gelsinger, who died after receiving genetic therapy at the University of Pennsylvania in the U.S.. Doctors inserted a cold virus into Gelsinger’s liver in order to cure his genetic disease. Instead, the therapy caused his immune system to attack and destroy not only the harmful virus but also his heart, liver , and kidneys. This case is especially regrettable because scientists encouraged the patient to undergo this therapy, but did not tell him about the potential dangers.

In addition to the physical dangers of gene therapy, there are also ethical issues. At what stage in a person’s illness will gene therapy be used—as soon as the illness is discovered or only after all other traditional methods have failed? Who will be responsible for conducting gene therapy—university researchers, medical doctors, or pharmaceutical companies? Who will have access to this expensive technology—people in rich, developed countries or people in poorer, developing areas of the world? These and other questions will continue to concern society as DNA and gene technology advance.

 

Glossary

Afflict: Cause pain or suffering.

Ancestry: The descendants or blood relative of one individual.

Blood clotting: A process in which liquid blood changes into a semisolid (a blood clot).

Carrier: An individual who does not show symptoms of a disease but has the genes for it and can transfer it to his/her child.

Cell (human): In biology, a structure surrounded by a membrane and containing genetic material (DNA) on the inside. Considered by most biologists to be the basic unit of life.

Chromosome: In organisms without a nucleus (such as bacteria), this is a circular DNA molecule used in genetic engineering. In organisms with a nucleus (including plants and humans), this is one of the threadlike structures within the nucleus that contains DNA.

Conduct: To act, guide, or manage (usually conduct research or experiments).

Convict: To find or prove (someone) guilty of an offense or crime, especially through the verdict of a court.

Destiny: Fate. A future that an individual cannot control.

Detect: To notice; to find; often used to describe the discovery of a disease.

Devastating: Terrible; causing great harm.

DNA: (deoxyribonucleic acid) A molecule in the form of a double helix , found within a structure known as a chromosome, within the nucleus of every living cell. First discovered in the 19th century, it controls the daily operation of a cell, and provides the genetic "blueprint" for the physical characteristics of all living organisms.

DNA testing: The analysis of human DNA, RNA, chromosomes, and proteins in order to detect the presence or potential presence of an inheritable disease.

Ethics: A set of principles of proper conduct. A system of moral values.

Extinct: No longer existing or living.

Gene: A small stretch of DNA that directs the production of proteins. A hereditary unit that occupies a specific position (locus) on the chromosome. This unit has a specific effect on the physical characteristics of the organism and can house one of many different allele forms (each allele causes a different trait).

Genealogy: A record or chart of a person’s extended family going back many generations; a family tree.

Genetic make-up: All the chromosomes and the information they contain. The genes of an individual.

Genetic testing: The checking of an individual's genetic material to predict present or future disability or disease, either in the individual or his/her children.

Gene therapy (human): Insertion of normal DNA directly into cells to correct a genetic defect.

Gene transfer: The movement of genetic material (DNA) from the laboratory into a human subject.

Human genome: The full collection of genes in a human being.

Human genome project: The scientific project to "read" the DNA of human chromosomes. Consists of not one project, but rather hundreds of separate research projects conducted throughout the world. The objective is to create a directory of the genes that can be used to answer questions such as what specific genes do and how they work..

Immune system: A system which protects the body from disease causing agents.

Inherited disease: A disease or disorder that is inherited genetically.

Liver: An organ in the body which helps with metabolism, digestion, detoxification, and elimination of substances from the body.

Malignant cells: Cells that grow uncontrollably.

Obesity: The condition of having excessive body fat.

Paralysis: The loss of motor functions; the inability to move one´s muscles.

Pharmaceutical companies: Companies that make drugs or medicines.

Potential: 1. Possible. 2. Able to grow and develop.

Side effect: An unexpected, usually undesirable reaction to a medicine or therapy.

Tissue sample (human): A small portion of a group of similar cells taken for research of medical purposes.

Trial: The formal presentation of evidence and arguments when a person is accused of a crime.

Undergo: To experience; to endure; to suffer.

 

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