Genetic Screening

Jason Kjono

Copyright 1997

Genetic screening techniques are coming of age and the controversy that surrounds them is growing by the minute. The definition of genetic screenings is as follows: a systematic search for persons with a specific genotype. These tests that look into the essence of humanity, will allow scientist and physicians the opportunity and ability to alter the human genotype for better or worse. Genetic advancements will bring controversy at every milestone. Genetic Screening usually takes place when an individu al or group shows risk for a disease or trait. Genetic testing can pinpoint a specific allelic interaction or multiple gene interactions, which may lead to a disorder. The common thread of life is DNA and DNA is the only major requirement for genetic sc reening. With knowledge of structure and function of DNA scientists can unlock the mysteries of life.

Who should be tested, when should someone be tested and who should know about the results are some of the small questions that society must answer about the ethics of genetic testing. Ethics plays a major role in understanding the controversy that surrou nds genetic testing. In the following pages I will discuss ethics, techniques, types of test available, major issues, pros and cons associated with genetic screening and finally my opinion.

To fully understand the concept of genetic screening some essentials background knowledge is required. First, life replicates itself for the most part in the same manner in all organisms. Second, DNA is the molecule of heredity. DNA provides life its bl ueprints for building, replicating and surviving. Humans have a wide variety of DNA sequences, but the majority of sequences are common to all humans. DNA condenses to form chromosomes. Humans have forty-six chromosomes that form twenty-three pairs; ea ch chromosome is made up of thousands of genes. Gene interaction controls the physical and structural characteristics of organisms. Allelic pairs make up genes. Interactions between different types of alleles create different genotypes, which is expres sed by different phenotypes. The process of mapping of the complete human chromosome is called the human genome project. The information gained by the sequencing of the human chromosome can be compared and contrasted with the DNA sequences of individual s that posses a certain trait. This will allow scientist to determine which gene or sets of genes control a trait. After a trait is defined and the most likely sequence mapped, a genetic test can be developed to compare the sequences of an individual and determine if the individual is predetermined to develop a disease or trait. By using comparative analysis techniques, genetic screening plays the role of an indicator. The results allow insight into whether the individual shows trends towards risk of con tracting a disease. The process doesn't necessarily determine whether or not an individual will have a trait rather it will show the genetic makeup that is most likely responsible for that trait.

Ethics in genetic screening doesn't play a role in the science of genetics, but it plays a major role in how the public opinion is formed. The playing god factor has religious groups and others screaming. The general public opinion is usually formed for the most part by uninformed individuals that are jumping to conclusions. According to Stephanie Yanchinski of Toronto Biotechnology Initiative some of the major issues of genetic screening are as follows: 1. Genetic screening will be expensive, who will pay for the procedures? 2. Should screening for common diseases be done? 3. Finding the gene does not necessarily predict severity and will this knowledge create emotional distress? 4. Prenatal screening could allow parents to perform social enginee ring? 5. Genetic tests are done by drawing blood, how will we ensure it is not done without our knowledge? 6. Genetic knowledge may be used to deny employment, social services and insurance benefits? 8. Banks could use genetic tests to deny loans, mor tgages and insurance? In the following sections I will address some of these issues and categorize them as pros or cons.


Imagine you find out that you have a genetic disorder that may shorten your life span and there is no known cure. The initial shock to yourself and your family would be harsh. The genetic test only indicates you have certain sequence linked to a diseas e or trait. A genetic test will not indicate the severity or even if the disease will manifest itself, it only shows that an individual has a genetic sequence that is suspect for causing a disease. The stress of planning a life on predetermined schedule would affect an individual emotionally and physically. "The Anxiety of living with the likelihood of one or more specific, chronic, debilitating disease create psychological burdens that outweigh the therapeutic potential of lifestyle changes or earlier treatment due to increase vigilance", states Bill Allen in USA Today Nov 1994. Emotional burden may be placed on an individual by their physician who may not be properly trained in genetic counseling. This fact may also cause an increase in malpractice suits against physicians, because there are only about 1,000 qualified specialist practicing. (Time,29)

Genetic specimens are easy to obtain. With a prick of the finger a small amount of blood can be collected. With this small amount of blood most genetic analysis test can be run. One of the hottest topics about genetic testing is who should have access to the results. A major concern in the genetic testing debate is how to insure that tests are not run without an individual knowledge or consent. Confidentiality of an individuals genetic makeup could be tested by parties interested in the results. With acc ess to a genetic profile companies may use the information they obtain against the individual. At present all medical records are confidential and only under certain circumstances may a physician inform anyone of its contents.

Insurance is based on the complementary principles of solidarity and equity in the face of uncertain risks (Harper, 225). It is plausible that if insurance companies could use the results of genetic test many people would be denied vital health and life insurance. The goal of business is to make money. Selling insurance to an individual predetermined to have a genetic disorder (whether they have it or not) is not a money making proposition, because of the increased rate the company would pay out for the individuals health needs. The denial of insurance brings out the classical case of discrimination. Discrimination due to genetic composition is the loudest alarm in the genetic screening debate (Stalwick,1995). Genetic discrimination by insurance comp anies could leave millions of people without protection and cause an increased burden on the already flooded medical assistance programs.

Social stigmatism may be placed on individuals and families because of the results of genetic tests. Along with social stigmas employers could deny jobs to individuals that are at risk for certain diseases. For example a technical field that requires a long train in process may turn down a qualified applicant if they knew that the applicant had a chance of contracting a debilitating disease. The company looks at both the time and money spent on training and compares that with the amount of productivity they could receive from that individual and determine if it would be better to hire a individual that has the potential for a longer tenure. The company may also look at the possibility that insuring that marked individual would drive up insurance cost. Another example is if an individual is screened and carries a trait and that trait would be induced in that particular work environment. The company would worry about a lawsuit being brought against them for causing the expression of the disease. Another big issue is that of prenatal screening being used for selection of desired traits not for disease control. Social engineering is bringing about individuals that have desired traits. This concept to me is not far off of what the Nazi Germans tri ed in World War II. Increased stamina, altheticism, IQ, beauty and size are some traits that may be desired by parents. Since most traits are controlled by multiple interactions this is not feasible, but some would still try.


The benefits of genetic screening are that the results can be used for many purposes. In the case of prenatal testing a diagnosis can be made on a suspect fetus that will allow ample time for decision to be made about treatment. Unfortunate as it is, ab ortion is the right answer in severe cases. Results from genetic tests can also help predetermine the carrier status of couples planning parenthood. With the information from genetic tests a couple can decide if the risk of having a child with a certain genetic makeup outweigh the advantages. In some cases changing habits can help slow down a disease. With prior knowledge of their genetic status some may change their lifestyle and therefor increase their life span.

Genetic tests are expensive in the United States at this time compared to Britain. For example a cystic fibrosis test in Britain can cost $2 while the same test in the United States may cost up to $300. (Roberts, 1990) This example shows that cost of te st is relative. The British system takes into account the money saved by proper treatment and genetic counseling. The more common use of genetic testing will bring down the cost of the tests. Money would be saved thereby relieving some of the burden on the health care system. Emotional pain could also be reduced by providing people options along with counseling on prenatal and presymtomatic issues. According to the Robin Blatt of the Gene Letter there are three main test groupings and two event induced groupings they are as follows: prenatal genetic testing, neonatal genetic screening, carrier screening tests (adults and adolescents), premarital gen etic screening and presymtomatic (predictive) genetic testing. Prenatal genetic tests are preformed on pregnant women to provide information on the health of an unborn child. This type of screening is used to determine a course of action for planning birt h, abortion (in some cases) and special needs. Prenatal genetic tests provide insight that allows parents the piece of mind or opportunity to make difficult decision prior to birth. Neonatal genetic tests are test done on newborns and infants usually i n hospital setting. Most states require some sort of genetic test at birth (Blatt, 1996); drawing blood from the heel of the infant does this. Neonatal genetic tests are used to determine inborn errors of metabolism, which can cause complications later in life. Diagnosed correctly an infant can often be treated and can avoid any life threatening complications. Carrier screening tests are given to individuals that are high risk, such as certain ethnic groups that contain certain disease causing allele. An example is a test for Tay Sachs disease that is carried by Jewish people of East European descent. Tay Sachs screening has decreased the occurrence of the disease ten-fold in many communities (Stawicki,1995). Pre marital genetic screening is used by some ethnic cultures to help determine compatibility and genetic status of couples. Presymptomatic and predictive test are given to determine individuals with specific health problems. These test help in predicting the possible outcomes of genetic fa ctors. With the use of the above test grouping a complete and accurate genetic testing pattern can be set for individuals throughout life stages. Listed below are some of the most common test, purposes and what the results can determined.


1. Maternal serum alpha-fetoprotein (MSAFP) is a common blood-screening test that is performed early in pregnancy to determine the chance of fetus carrying neural tube conditions. 2. Enhanced MSAFP is a genetic screening test that measures biologic markers to determine the possibility of fetal Down syndrome. 3. Fetal ultrasound is one of the most common screening procedures during pregnancy. A transducer sends a sound wave that provides a picture of the fetus. This procedure is used to date the pregnancy, assess structure and position of the fetus. 4. Amniocentesis is a surgical tap into the uterus to obtain amniotic fluid. The amniotic fluid can be analyzed to determine genetic status of fetus. 5. Chorionic Villus Sampling (CVS) is removal of a piece of chorion, which is the outer tissue surrounding the embryo. The tissue sample is used to analyze chromosome, biochemical and DNA status. This test like MSAFP helps to determine if neural tube di sorders are present, such as spinal bifada or acenecephaly. 6. Percutaneous Umbilical Blood Sampling (PUBS) is a fetal blood sample test that takes measurements of fetus blood components. These results are used to clarify other test results. 7. Fetal Biopsy takes tissue cultures from different regions of the fetus to determine genetic makeup and perform DNA tests on the developing fetus. 8. Preimplantation genetic diagnosis is used to detect whether or not gametes contain genes for a specific disease prior to the gamete being fertilized. These results help determine the status of gametes and help determine which gamete should be used for fertilization.


1. Inborn errors of metabolism are tests run on all infants to determine rare disabilities or chemical disorders like PKU, sickle cell disease and thalassemia. Some new test such as HIV, heart disease and cystic fibrosis are also done.


1. Sickle cell anemia tests are run on blacks to determine the presence of sickle cells. 2. Tay-Sachs is tested for in the descendants of Jewish person form Eastern Europe. 3. Thalassemia tests are run on people from the Mediterranean and Southeast Asia. 4. Women suspect for having a specific gene on the X chromosome. This gene can lead to hemophilia or Fragile X syndrome.

In my opinion of genetic screening I am torn between the two sides. My scientific side thinks that all advances are good and properly used can only help mankind. With the proper agency controlling the research and application, genetic screening would be a great asset that could reduce a lot of human suffering. What scares me is the availability of the results to the outside community; genetic test should be confidential. Only the necessary people such as individual, family, physician and counselor sho uld know the results of a genetic tests. If the genetic makeup of a person becomes common knowledge problems occur with discrimination, employment and insurance. The emotional or conservative part of myself feels that if a disease or genetic trait has n o cure and doesn't show much chance of being curtailed the test should not be run. The mental and physical strain that would be put on an individual and family would far outweigh any benefits that would be gained from knowing. In summary I believe that research and testing should continue, but test should only be done for individuals that have a curable disease. There also needs to be agency of qualified individuals watching over the research, application and information that genetic test can provide. All in all I feel that genetic screening and genetic test are the way of the future and can benefit all with proper regulation.


Reference 1.
Allen, B., (1994). Predictive genetic testing: ethical, legal and social implications. USA Today Nov 1994:66-69. Reference 2.
Harper, P., (1993)Insurance and genetic testing. The Lancet Jan1993:224-228. Reference 3.
Roberts, L. (1990) To test or not to test? Science 247:17-19. Reference 4.
Time(1996) Do you want to know if the news is bad? Time v148:29 Reference 5.
Blatt, R., An Overview of Genetic Screening and Diagnostic Test in Health Care. Obtained form
Reference 6.
Stawicki, S., Pros of Genetic Screening. Obtained form:
Reference 7.
Ynachinski, S., Genetic Screeing for Disease. Obtained form

Student Essay List

Course Homepage