Genetic Testing

Genetic testing is a type of medical laboratory test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.

More than 2,000 genetic tests are currently in use, and more are being developed.

Several methods can be used for genetic testing:

• Chromosomal genetic tests analyze whole chromosomes or long lengths of DNA to see if there are large genetic changes, such as an extra copy of a chromosome, that cause a genetic condition.
• Biochemical genetic tests study the amount or activity level of proteins; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.

Different types of genetic tests include:

• Diagnostic testing is used to precisely identify the disease that is making a person ill. The results of a diagnostic test may help you make choices about how to treat or manage the patient’s health.
• Predictive and pre-symptomatic genetic tests are used to find gene changes that increase a person’s likelihood of developing diseases. The results of these tests provide information about a patient’s risk of developing a specific disease. Such information may be useful in decisions about lifestyle and healthcare.
• Companion diagnostics are in vitro diagnostic devices or imaging tools that provide information essential for the safe and effective use of a corresponding therapeutic product for a specific individual, based on his or her DNA.
• Carrier testing is used to find people who “carry” a change in a gene that is linked to disease. Carriers may show no signs of the disease; however, they have the ability to pass on the gene change to their children, who may develop the disease or become carriers themselves. Some diseases require a gene change to be inherited from both parents for the disease to occur.
• Prenatal testing is offered during pregnancy to help identify fetuses that have certain diseases.
• Newborn screening is used to test babies one or two days after birth to find out if they have certain diseases known to cause problems with health and development.
• Pharmacogenomic testing gives information about how certain medicines are processed by an individual’s body. This type of testing can help healthcare providers choose medicines that work best with a patient’s genetic makeup.
• Research genetic testing is used to learn more about the contributions of genes to health and to disease. Sometimes the results may not be directly helpful to participants, but they may benefit others by helping researchers expand their understanding of the human body, health, and disease.

Advancing research into the human genome and ongoing interest in personalized medicine are both driving an increasing volume of genetic testing for clinical laboratories.