Genetic testing is a type of medical test that identifies changes in genes, chromosomes, 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 77,000 genetic tests are currently in use, and others are being developed.
Genetic testing involves looking for changes in:
- Genes: Gene tests study DNA sequences to identify variations (mutations) in genes that can cause or increase the risk of a genetic disorder. Gene tests can be narrow or large in scope, analyzing an individual DNA building block (nucleotide), one or more genes, or all of a person’s DNA (which is known as their genome).
- Chromosomes: 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.
Proteins: Biochemical genetic tests study the amount or activity level of proteins or enzymes; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.
Genetic testing is voluntary. Because testing has benefits as well as limitations and risks, the decision about whether to be tested is a personal and complex one. A geneticist or genetic counselor can help by providing information about the pros and cons of the test and discussing the social and emotional aspects of testing.
Topics in the Genetic Testing chapter
- What is genetic testing?
- What are the different types of genetic tests?
- What are the uses of genetic testing?
- How is genetic testing done?
- What is informed consent?
- How can I be sure a genetic test is valid and useful?
- What do the results of genetic tests mean?
- What is the cost of genetic testing, and how long does it take to get the results?
- Will health insurance cover the costs of genetic testing?
- What are the benefits of genetic testing?
- What are the risks and limitations of genetic testing?
- What is genetic discrimination?
- Can genes be patented?
- How are genetic screening tests different from genetic diagnostic tests?
- How does genetic testing in a research setting differ from clinical genetic testing?
- What are whole exome sequencing and whole genome sequencing?
- What are secondary findings from genetic testing?
- What is noninvasive prenatal testing (NIPT) and what disorders can it screen for?
- What is circulating tumor DNA and how is it used to diagnose and manage cancer?
The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.