Genetic Screening

Kristin Berg

Copyright 1998

You are sitting in the counselor's office, waiting. You are staring at the walls, trying not to think about what you are considering, but still thinking about it. Will I get cancer? Do I have the gene that will increase my likelihood of getting cancer ? My grandmother had cancer. Two of my aunts have had cancer. What about me? If I have this test, what happens then? The door opens and in walks the counselor. Time to find out about genetic screening.

Genetic screening with today's technology is a fairly simple. It's the public opinion and individual morals which make genetic screening complicated. I will address basic background information on genetic screening, the technical aspect of genetic scre ening, the public opinion surrounding genetic screening and my own personal opinion on genetic screening.

Background Information

Knowing two things will allow better understanding of what genetic screening is and how it is done. The first item covers basics about DNA and how it is inherited. The second deals with research done which allows genetic screening of a gene.

1. DNA is inherited from both parents, half from the father and half from the mother. Each half contains DNA segments which code for the same gene. Each part of the These two segments are called alleles. It is these alleles inherited from the parents that are used for analysis in genetic screening.

2. Genetic screening is a result of complex research. The gene must be located and sequenced. Changes in the DNA sequence caused by mutation, additions, or deletions, that result in disease development must also be found. It is these changes one is lo oking for in genetic screening.

Technical aspects of genetic screening

Individual genetic screening is fairly simple with current technology. The process involves DNA isolation, amplification, sequencing and analysis. One example of genetic screening currently used, is screening for the defective breast cancer (BRCA) alle les. In addition to the genetic screening process, an individual undergoes several counseling sessions. The step by step process of individual genetic screening starts with isolation of an individual's DNA. DNA may be isolated from tissue cells, blood cells, or urine of a child, adult or fetus. The segment of DNA which contains the gene of interest, is th en amplified through the use of PCR (Polymerase Chain Reaction) with primers specific to the segment of DNA. The amplified segment of DNA is then sequenced and analyzed for changes which cause the particular disease. If changes are present, the individu al has a greater likelihood of getting the disease.

In the case of BRAC screening an individual with a family history of breast cancer would be genetically screened for a copy of the defective allele. Their DNA would be isolated, amplified, sequenced, and analyzed. If a copy of one of these defective all eles is present, the individual would have a greater likelihood of getting breast cancer than the average individual. Groopman (1998) states "Women who inherit a single defective copy of either BRCA1 or BRCA2 are at a significantly increased risk for bea st and ovarian cancer over the course of their lives."

Besides the actual screening, an individual also has counseling, both before and after the screening. The counseling session before the screening helps the individual decide if they want the test done, want to know the results and understand possible ram ifications of the different possible test results. The session after the screening allows the individual to hear an explanation of the results and what they mean. They are also given a list of options. In the case of testing positive for a defective g ene either BRCA1 or BRCA2, one would be faced with two options. One could enter a program of high surveillance or one could opt to have the breasts and ovaries surgically removed (Groopman, 1998). One may also face other problems like insurance discrimi nation and other social discrimination (Laino, 1998).

Public Opinion

Public opinion about genetic screening varies for several reasons. People are either informed or not informed about genetic screening. Uninformed people tend to misinterpret the screenings. People have also been exposed to unorganized genetic screenin g programs. The following two situations show how public opinion varies depending on how the programs were handled.

The first situation involved an unorganized genetic screening program for sickle cell anemia. Initial public support of sickle cell anemia screening was strong. The people were well informed about the screening and what the results meant. People who w anted to be tested could be tested. Then some state legislatures passed laws to require the sickle cell anemia screening. When the testing became mandatory due to laws passed, people were no longer educated about the testing and what the results meant. People believed they were sick if the test came back showing they were a carrier of sickle cell anemia. Insurance companies took this ignorance one step further and denied coverage to sickle cell anemia carriers on the basis of pre-existing conditions ( Rennie, 1994). This situation of uninformed people and mandatory testing led to a low public opinion of genetic screening.

This second situation was one which was completely organized which did not require mandatory testing and left the people informed about the results. This situation involves parental and fetal screening for the Tay-Sachs allele. This genetic screening pr ogram started out educating people about the disease and the genetic tests. The screening was introduced in a small testing area. The screening was kept voluntary and coupled with counseling. With this type of organization high risk parents could deter mine if they were carriers for the disease. If both parents tested positive for the defective allele, their fetuses could also be tested. If the child had two copies of the defective allele, the child could be aborted. Many people believe genetic scree ning in this situation is okay because Tay-Sachs is considered to be a terrible disease. According to Rennie (1994) the genetic screening for Tay-Sachs carries a "clear benefit." This sort of situation leads to much stronger public support.

From the previous situations one can find both advantages and disadvantages to using genetic testing. The major disadvantages of genetic screening are all the negative impacts felt by the individual tested and/or their families. The individual needs to decide whom to tell. So far only their doctor knows. Do they tell their spouse, their children, their employer, their insurance company? What will happen when these other people are told? Will they be rejected by their spouse? Will the knowledge chang e the family's relationships for the worse? Will they be discriminated against on the job or for health insurance (Laino, 1998) as the people screened for sickle cell anemia were? None of these questions have easy answers. The answers will be different for each individual. These questions and answers focus on the way genetic screening negatively impacts an individual.

Genetic screening can also positively impact an individual. If an individual knows they have a greater likelihood of getting a disease, they have more options to help prevent the development of the disease. An example is finding one has a mutated BRCA a llele. The individual has a greater likelihood of developing breast cancer. They may change their living style, enter a high surveillance program or undergo surgery. It gives the individual information necessary if they want to change their lifestyle. With Tay-Sachs it gives a family a chance to bring a healthy child into the world instead of one with Tay-Sachs. This would save a child from a slow and painful death.

Overall Americans can not seem to make up their mind on genetic screening. As far as privacy of the test results 57% of Americans feel someone other than the tested individual needs to know the results of the test. Of those Americans 98% thought the sp ouse should know, 58% insurance companies, and 33% thought employers should know (Rennie, 1994).

Personal Opinion

Considering the above information, I believe genetic screening is a positive effect of technology. I think the advantages outweigh the disadvantages. I do think there needs to be some limitations. I think that counseling should be a mandatory part of the testing process. The counseling allows people to prepare themselves mentally for the test as well as for accepting the results of the test. This time would also allow more time for direct discuss ion with the doctor about possible options based on the test results. I also believe that the testing should be primarily limited to life threatening diseases. We do not need to choose the features and other similar traits of our children. I think that the privacy of these tests is very important.

I, if I was placed in a situation where I was at high risk for a disease, would want to be tested if possible for the defective allele. I believe it would be a very difficult decision to make though it seems easy now. I would want the results of the te sting kept confidential. I feel it is my right to disclose this information to whom I choose. I believe I would share the results with my spouse provided it would not bring up old wounds between us.

I believe sharing the results with others could change the rest of my family relationships. I think I would rather life continued on normally with no changes in lifestyle or relationships. I also believe sharing the results would create discrimination. I look at discrimination in the work place now. I can only imagine what it would be like if they knew I had a disease even though it would not endanger any one else. I also think it would be difficult to get health insurance if I had a higher likeliho od of getting a disease.

Based on my beliefs, I feel genetic screening is great with certain limitations.


Groopman, Jerome. The New Yorker. "Decoding Destiny." February 9, 1998. p 42-47

Laino, Charlene. Protect against gene discrimination. Obtained from WWW 11/1/98: 11/1/98:

Rennie, John. Scientific American. "Grading the Gene Tests." June 1994. p 88-97

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