The key difference between genetic testing and screening is that the genetic testing is performed on an individual while genetic screening is performed on a population.
Genetic testing and screening are two methods of disease prevention. These methods help to evaluate the risk of a genetic disorder in an individual or in a population respectively. Therefore, genetic testing determines the risk of having genetic disorders in an individual after performing rigid lab tests. Genetic screening confirms the risk of a population who carry the specific genetic disorders. Both methods use lab tests. More specifically, pregnant women undergo these two procedures more often.
CONTENTS
1. Overview and Key Difference
2. What is Genetic Testing
3. What is Genetic Screening
4. Similarities Between Genetic Testing and Screening
5. Side by Side Comparison – Genetic Testing vs Screening in Tabular Form
6. Summary
What is Genetic Testing?
Genetic testing is the use of laboratory tests to determine the risk of having a genetic disease or genetic defects in an individual who has a family history of having that disease. Genetic testing performs only on an individual, not on population. It reveals the presence or absence of the particular gene that causes the genetic disease.
Figure 01: Genetic Testing
Any individual who suspects to have the disease gene can undergo genetic testing and confirms it. However, prior to genetic testing, he or she can take a screening test and based on the results and the medical history of the family, can go for genetic testing. As an example, a person belonging to a family with a background of cystic fibrosis can undergo genetic testing to identify the presence of the specific gene causing cystic fibrosis. Genetic testing involves rigid diagnostic tests such as microarray, karyotyping, FISH, etc.
What is Genetic Screening?
Genetic screening is a medical test that employs a population in order to find out the possibility of having a specific genetic disorder within a certain age group or an ethnic group. It is a population-based screening. It does not perform for an individual. Individuals may be asymptomatic. But if a person wants to confirm about the risk of getting or not getting a particular genetic disorder that prevails in a population, he may go for a genetic screening prior to genetic testing. Genetic screening uses a set of diagnostic tests. But they are not rigid as in genetic testing.
Figure 02: Genetic Screening
Once genetic screening performs on a population, it is easy to know which members of the population carry disease genes and which do not and which have a high risk etc. As an example, Sickle cell disease is more prone to get by African Americans. Hence, they use genetic screening to find out the presence of this specific gene among their population. Another example is that most pregnant women undergo genetic screening to decide which genetic testing to take based on the results obtained from genetic screening. Genetic screening includes family history, prenatal screening tests, newborn screening, M-CHAT screening for autism etc.
What are the Similarities Between Genetic Testing and Screening?
- Genetic screening and genetic testing are terms that are often encountered in prenatal screening with pregnant women.
- Both procedures involve the use of laboratory tests to identify the presence of specific genes that may cause genetic disorders, hence very important genetic procedures.
- Genetic Testing and Screening involve the same medical procedures.
- Results of the genetic screening can decide whether it is necessary to undergo genetic testing.
- Both methods help to prevent diseases.
- Genetic Testing and Screening look for the presence of genes.
What is the Difference Between Genetic Testing and Screening?
Genetic Testing and Screening are two diagnostic methods of genetic diseases. Genetic test is performed on an individual to reveal the presence of a particular gene which causes the disease while genetic screening is performed on a population to reveal the risk of people getting the disease by having the particular disease-causing gene. Thus, genetic testing may lead to treatments and prevention of disease while genetic screening leads to testing and then treatments.
The below inforgraphic presents more details on the difference between genetic testing and screening in tabular form.
Summary – Genetic Testing vs Screening
Genetic testing and screening will help to recognize genetic defects. Genetic testing is used to screen an individual for a genetic defect while genetic screening is performed on a population to find out who is carrying the genetic disease and who is having the high risk of getting it. Moreover, genetic testing involves different expensive diagnostic tests while genetic screening involves simple diagnostic tests, which are cost effective. This is the difference between genetic testing and screening.
Reference:
1.“Genetic Testing vs. Genetic Screening.” Bright Hub, 25 Mar. 2011. Available here
2.“Genetic Screening.” Egyptian Journal of Medical Human Genetics, Elsevier. Available here
Image Courtesy:
1.”2316642″ by mcmurryjulie (CC0) via pixabay
2.”Autorecessive” By en:User:Cburnett – Own work in Inkscape, (CC BY-SA 3.0) via Commons Wikimedia