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<span>How is genetic testing done?</span>
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<h1>How is genetic testing done?</h1>
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<section><div class="mp-content"><p>Once a person decides to proceed with genetic testing, a health care provider can arrange testing. Genetic testing is often done as part of a <a data-pid="20209" href="https://medlineplus.gov/genetics/understanding/consult/expectations/">genetic consultation</a>.</p>
<p>Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a procedure called a buccal smear uses a small brush or cotton swab to collect a sample of cells from the inside surface of the cheek. The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorder. The laboratory reports the test results in writing to a person's doctor or genetic counselor, or directly to the patient if requested.</p>
<p>Newborn screening tests are done on a small blood sample, which is taken by pricking the baby's heel. Unlike other types of genetic testing, a parent will usually only receive the result if it is positive. If the test result is positive, additional testing is needed to determine whether the baby has a genetic disorder.</p>
<p>Before a person has a genetic test, it is important to understand the testing procedure, the <a data-pid="20235" href="https://medlineplus.gov/genetics/understanding/testing/benefits/">benefits</a> and <a data-pid="20237" href="https://medlineplus.gov/genetics/understanding/testing/riskslimitations/">limitations</a> of the test, and the possible consequences of the test results. The process of educating a person about the test and obtaining permission is called <a data-pid="20225" href="https://medlineplus.gov/genetics/understanding/testing/informedconsent/">informed consent</a>.</p><p>Individuals interested in <a data-pid="20253" href="https://medlineplus.gov/genetics/understanding/dtcgenetictesting/directtoconsumer/">direct-to-consumer genetic testing</a> do not need to go through a health care provider to obtain a test, but they can get it directly from the testing company. After undergoing direct-to-consumer genetic testing, people who test positive for a condition or are found to be at higher risk of developing a disorder are encouraged <a data-pid="20209" href="https://medlineplus.gov/genetics/understanding/consult/expectations/"></a>to follow-up with a genetic counselor or other health care provider. </p></div>
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<h2>For more information about genetic testing procedures:</h2>
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<p>A <a href="https://www.cancer.gov/about-cancer/causes-prevention/genetics/genetic-testing-fact-sheet#how-is-genetic-testing-done" rel="noopener noreferrer" target="_blank">brief overview of how genetic testing is done</a> is also available from The National Cancer Institute.<span class="desc-text"><img alt="From the National Institutes of Health" class="imgdesc" height="16" src="https://medlineplus.gov/images/nih.png" title="From the National Institutes of Health" width="25"/></span></p>
<p>The Genetic Science Learning Center at the University of Utah provides an <a href="https://learn.genetics.utah.edu/content/labs/extraction/" target="_blank">interactive animation of DNA extraction techniques</a>.</p>
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<section><div class="mp-exp mp-content"><h2>Topics in the Genetic Testing chapter</h2>
<ul><li><a data-pid="20219" href="https://medlineplus.gov/genetics/understanding/testing/genetictesting/">What is genetic testing?</a></li><li><a data-pid="31121" href="https://medlineplus.gov/genetics/understanding/testing/types/">What are the different types of genetic tests?</a></li><li><a data-pid="20221" href="https://medlineplus.gov/genetics/understanding/testing/uses/">What are the uses of genetic testing?</a></li><li>How is genetic testing done?</li><li><a data-pid="20225" href="https://medlineplus.gov/genetics/understanding/testing/informedconsent/">What is informed consent?</a></li><li><a data-pid="20227" href="https://medlineplus.gov/genetics/understanding/testing/validtest/">How can I be sure a genetic test is valid and useful?</a></li><li><a data-pid="20229" href="https://medlineplus.gov/genetics/understanding/testing/interpretingresults/">What do the results of genetic tests mean?</a></li><li><a data-pid="20231" href="https://medlineplus.gov/genetics/understanding/testing/costresults/">What is the cost of genetic testing, and how long does it take to get the results?</a></li><li><a data-pid="20233" href="https://medlineplus.gov/genetics/understanding/testing/insurancecoverage/">Will health insurance cover the costs of genetic testing?</a></li><li><a data-pid="20235" href="https://medlineplus.gov/genetics/understanding/testing/benefits/">What are the benefits of genetic testing?</a></li><li><a data-pid="20237" href="https://medlineplus.gov/genetics/understanding/testing/riskslimitations/">What are the risks and limitations of genetic testing?</a></li><li><a data-pid="20239" href="https://medlineplus.gov/genetics/understanding/testing/discrimination/">What is genetic discrimination?</a></li><li><a data-pid="20241" href="https://medlineplus.gov/genetics/understanding/testing/genepatents/">Can genes be patented?</a></li><li><a data-pid="31501" href="https://medlineplus.gov/genetics/understanding/testing/differenttests/">How are genetic screening tests different from genetic diagnostic tests?</a></li><li><a data-pid="20243" href="https://medlineplus.gov/genetics/understanding/testing/researchtesting/">How does genetic testing in a research setting differ from clinical genetic testing?</a></li><li><a data-pid="20245" href="https://medlineplus.gov/genetics/understanding/testing/sequencing/">What are whole exome sequencing and whole genome sequencing?</a></li><li><a data-pid="20247" href="https://medlineplus.gov/genetics/understanding/testing/secondaryfindings/">What are secondary findings from genetic testing?</a></li><li><a data-pid="20249" href="https://medlineplus.gov/genetics/understanding/testing/nipt/">What is noninvasive prenatal testing (NIPT) and what disorders can it screen for?</a></li><li><a data-pid="20251" href="https://medlineplus.gov/genetics/understanding/testing/circulatingtumordna/">What is circulating tumor DNA and how is it used to diagnose and manage cancer?</a></li></ul>
<p><a data-pid="20081" href="https://medlineplus.gov/genetics/understanding/">Other chapters in Help Me Understand Genetics</a></p></div>
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