Understanding Different Kinds of DNA Tests
Genetic testing has become a common way to identify a person's chances of inheriting or developing a particular disease later in life. As many as 900 different kinds of DNA tests are available to help individuals prevent and receive treatment before the development of a disease. You can receive DNA genetic testing at any time of your life. If you are thinking of having children someday, you can even receive this testing before conception to determine the risk of your children having an
inherited disease.
Defining Genetic Testing
Genetic testing involves taking blood, skin, saliva or another human sample for DNA analysis. Each gene on a chromosome has a particular code; when this code is abnormal, the gene has mutated. This mutation may indicate the person has a predisposition or susceptibility to a particular disease.
This mutation doesn't mean the person will definitely develop the disease; only that he is at risk and/or a carrier of the gene, which can be inherited by offspring. This can help you make decisions about your life, such as avoiding certain environmental factors that could further increase your risk of contracting a particular disease. For instance, if results indicate you are at risk for lung cancer, you may decide to quit smoking.
Another use of genetic testing is to determine if someone was successful in a particular therapy: It can determine if the person is still at risk for the disease.
Types of DNA Tests
DNA is the most common test to identify gene mutation, but RNA (Ribonucleic Acid) is also another gene component laboratories analyze. RNA is the part of the gene that translates messages, and is the protein that actually performs functions.
DNA diagnostic testing has five general uses, outlined below:
- Carrier detection: Individuals thinking of conceiving can have DNA genetic testing to see if they are carriers for a family history of disease.
- Prenatal analysis: After conception, the mother-to-be can have genetic testing through chrionic villus sampling (CVS) or amniocentesis to check for gene mutations indicating the possibility of genetic disorders.
- Newborn susceptibility: After birth, some newborns receive DNA diagnostic testing to identify any genetic condition he or she may develop later in life.
- Adult disease risk: Adults can receive genetic testing for information on their chances of developing cancer, heart disease or other diseases. Remember, testing only tells you if you are predisposed for a particular disease, environmental factors may influence whether or not you develop it.
- Identity: DNA testing can confirm or deny paternity/maternity or identify someone after death.
Issues with DNA Diagnostic Testing
Genetic testing has many benefits for the prevention and treatment of disease. However, it isn't without its limitations. It's possible for results to be false positive or false negative. Analyzing a DNA sample is complex, and it's possible that even the most experienced technician interprets the gene code inaccurately. This means that you may base critical life decisions on results that are potentially incorrect. One of the most important things to remember if you are considering DNA genetic testing is that it is just a screening tool.
Resources
National Human Genome Research Institute Staff. (2008).
A brief primer on genetic testing. Retrieved September 18, 2008, from the National Human Genome Research Institute Web site:
http://www.genome.gov/10506784.
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