Ethical Issues of Genetic Diagnosis

Ethical Issues of Genetic Diagnosis

Source: Perfect Genes

When should genetic testing be used?
Genetic testing for diseases that are preventable or treatable could be beneficial for patients by allowing them to alter their lifestyles so as to treat the disease or reduce their risk of developing the disease. For instance, the E2 version of the APOE gene has been linked to heart disease (3). Individuals who have two copies of the E2 gene are particularly sensitive to high-fat and high-cholesterol diets. Therefore, a genetic test to determine whether a person has the high-risk version of the APOE gene could inform a person of future health risks, thereby allowing the person to change his diet to help prevent future heart disease.

On the other hand, most bioethicists and medical professionals agree that genetic testing for incurable and untreatable diseases, such as Alzheimer's, is useless (1,3). Although a negative test may afford a person the reassurance that he or she will not develop the disease, a positive test could be a death sentence.

For example, since 1986 people who are at risk for Huntington's disease have had the option of being tested for the mutation on chromosome 4 that is linked to the disease (3).

In Genome, Nancy Wexler, a woman who set out to identify the Huntington's gene in the late 1970s, relates the story of a woman who asked doctors whether or not she had Huntington's disease (3). Although the doctors found that the woman was showing subtle signs of the disease, she could not detect these signs herself.

The doctors, rather than telling the woman that she had the disease, let her believe that she was well and did not have Huntington's disease. After the woman left the doctors' office, the woman's friend came into the office and asked the doctors what they had said to the woman, because earlier the woman had told her friend that she would immediately kill herself if she found out that she had Huntington's disease. Although the woman may have wanted to know her fate, this story illustrates the "uselessness of diagnosing without curing" (3, p. 63).

What family conflicts could arise from genetic testing?

Depending on the inheritance pattern of a genetic mutation, testing one family member for a specific mutation could be essentially testing all family members. However, not all family members may want to be tested for the mutation.

For instance, in Experiencing the New Genetics, Finkler relates the story of a woman who had a family history of breast cancer and participated in a breast cancer study that tested her for specific cancer-susceptibility genes (4). The woman wanted to know the results of the genetic test, but her mother and sister did not want to know the test results. The woman's genetic counselor was afraid that the woman would mention the test results to her mother and sister, and despite her desire to know the results, never told her the outcome of the test. This type of situation could create many conflicts within the family, especially if one family member tries to withhold the test results from others, yet attempts to treat or prevent the disease either through lifestyle changes or medical treatment.

Genetic testing could also create family conflicts as individuals who tested positive for deleterious mutations make decisions about having children. Huntington's disease is caused by a dominant gene in which a person needs only one, rather than two, copies of the gene to have the condition (3). This means that if one parent has one copy of the gene that causes Huntington's disease, and the other parent does not have the Huntington's gene, there is a 50 percent change that each of the couple's children will inherit the disease.

Since Huntington's disease tends to set in later in life, most people do not know if they have Huntington's disease until after they have children. However, if a man tests positive for the gene that causes Huntington's disease before he has children, conflicts could arise between him and his partner about whether or not to have children who have a 50 percent chance of developing the disease that will eventually claim the life of their father.

What are the social implications of genetic testing?

The general public has the common misconception that genetic tests for both treatable and untreatable diseases are 100 percent reliable, when in fact genetic tests can only assess the probability that an individual will develop a particular disease or illness. Despite the predictive, rather than deterministic, nature of genetic tests, testing positive often labels people as "sick" or "potentially sick" (1). These labels can then cause both the individuals and their families considerable social and psychological harm, creating a population of what Ruth Hubbard and Elijah Wald refer to as the "healthy ill" (1, pg 172).

Positive tests for incurable and untreatable diseases, in which patients feel helpless at being unable to control their health, could be particularly damaging for patients. For this reason, in 1993 the Institute of Medicine of the U.S. National Academy of Sciences advised against testing for incurable or non-preventable diseases (1).

Who should have access to results of genetic tests?
Currently, when we fill out forms for medical or life insurance, we must answer questions about our weight, our smoking and drinking habits, and our family history of heart disease (3). These questions are designed to provide insight into our risks for future illness or disease.

As scientific research on the human genome advances and more genetic tests for diseases are developed, will insurance companies also require that we provide them with the results of genetic tests, or perhaps provide them with a DNA sample, so that they can assess our risk for future illness? If insurance companies had access to the results of a wide variety of genetic tests and then charged people premiums in accordance with their genetic fitness, they could save money by charging people with high-risk genes absurdly high premiums (3).

In fact, a 1994 report from the American Council of Life Insurance states that it believes that insurance companies have the right to refuse insurance to individuals based upon the results of genetic tests for genes that predispose a person for cancer (1).

Since both genetic and lifestyle factors can contribute to a person's risk for future illness or disease, why does basing insurance premiums on genetic makeup seem so much more unethical than basing insurance premiums on lifestyle choices? The answer to this question lies in the difference between choice and determinism (3).

People can choose to indulge in habits that increase their risk for illness or disease, such as smoking or drinking, but people cannot choose their genes. Charging higher insurance premiums for individuals with genes that predispose them for certain illnesses is therefore as despicable as racial or gender discrimination.

As one can imagine, providing employers with the results of genetic tests could allow for similar genetic discrimination in the workplace. Although no laws currently deny access to genetic information to insurance companies and employers, lawmakers have recognized the potential discrimination that could result from disclosing genetic information to insurance companies and employers. As a result, multiple states have enacted laws that protect individuals from discrimination based on genetic predispositions for diseases (1).

Will prenatal testing lead to eugenics?

Before a woman gives birth to a child, she may have the fetus tested for a variety of genetic diseases. For instance, the state of California encourages all pregnant women to be tested for fetal neural tube defects (5). Rather than base the success of this program on the information given to mothers, the success of the program is based on the number of handicapped children who were not born. Relating the prevention of births of handicapped children to success suggests that negative eugenics motivates the program.

Genetic tests can also be used to test embryos for genetic diseases before in vitro fertilization (IVF) techniques are used to implant the embryo in the uterus (1). Fertile women who are at risk for specific conditions may choose to undergo in vitro fertilization so that they may screen the embryos for genetic disorders and then implant only the embryos that are free of genetic disorders.

Despite the high costs of in vitro fertilization, preimplantation testing may be advantageous for prospective parents because it allows them to avoid the birth of a handicapped child, yet does not require them to terminate a pregnancy by aborting a developing fetus. Nonetheless, selecting "good" and "bad" embryos, deciding that only the "good" embryos are worthy of life, may be viewed as a form of eugenics (1, pg 166).

Society's perceptions of people with disabilities and the definition of fitness are at the heart of the debate about prenatal testing. Making a decision about who is fit or unfit for life is a complex ethical decision. It is difficult, and perhaps unfair, for prospective parents to make judgments about whether or not a future child is worthy of life and will be able to live a fulfilling life. For instance, Down syndrome, which results from an extra copy of chromosome 21, can be detected with genetic tests. Although a child with Down syndrome certainly requires more parental care than a child without the condition, many people with Down syndrome live very full lives and are able to read, write, and have jobs (1). Is it fair for parents to decide to not have a Down syndrome child, who very likely could live a full life, because they do not want to invest the time and money to care for the child?

This type of ethical question surrounds all prenatal and preimplantation tests and should be carefully considered before health-care providers and prospective parents make the decision to use genetic tests to screen fetuses or embryos for genetic abnormalities.