DNA tests (gene testing) are medical tests that can identify changes (variations) in your genes, chromosomes and DNA. These tests can tell you and your healthcare provider if you have or don’t have a genetic disease. They can also determine your risk for developing a certain condition or passing on a genetic disorder to your child.
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DNA tests, or genetic tests, look for changes (variations) in your genes, chromosomes and DNA. This is also called gene testing. DNA tests can give you lots of information about your genetic makeup. They can often:
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
If you’re interested in gene testing, you should speak to a genetic counselor. They can help you decide if DNA testing is right for you, and if it is, which kind. They’ll also be able to help you understand the results.
Genetic tests may look at your genes, chromosomes and/or almost all of your genetic material, which is made up of DNA. Your healthcare provider will recommend certain tests based on several factors. These factors include your family history, medical history and any suspected genetic conditions.
Gene tests examine your genes to find changes that can cause or increase your risk of developing a genetic disease.
Gene tests include:
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Large-scale genomic tests look for changes throughout your DNA. Your provider may suggest genomic testing if other gene tests haven’t found a genetic reason for a condition. Or they may recommend it if you have a complex medical condition.
There are two kinds of genomic testing:
Chromosomal tests study your chromosomes — long strings of your DNA. This type of test looks for changes in your chromosomes instead of your genes. Chromosomal testing may find:
When a gene within a cell is active (turned on), it means the cell goes through the process of reading instructions and assembling a protein that will be expressed as a certain trait or condition.
Gene expression tests study the activity level of active genes. Certain conditions, including many kinds of cancer, may occur when a particular gene is too active (overexpression) or not active enough (underexpression).
Gene testing has many valuable uses. They can offer important information about your DNA or the genetic background of a loved one. The uses of DNA tests include:
Your healthcare provider can detect changes in the genes or chromosomes of a fetus through a prenatal genetic test while you’re pregnant. Prenatal testing can determine the chance of your baby being born with certain medical conditions. If your baby has an increased risk of having a condition because of your family’s genetic history or because there are signs of a condition in the fetus itself, your provider may recommend this type of test.
Diagnostic testing can confirm or rule out specific genetic disorders or chromosomal problems. But it doesn’t test for all genetic conditions. Healthcare providers often use diagnostic testing during pregnancy. But they can use it at any time to confirm a diagnosis if you have symptoms of a certain disease.
If a condition is autosomal recessively inherited, it means that you can carry a gene for that condition, but not have symptoms. Carrier screening can tell you if you carry a copy of an altered gene for an autosomal recessive disease. If both parents are carriers for the same condition, there would be a 25% risk of passing that on to a child.
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Providers offer this testing to everyone planning a pregnancy or who is in the early stages of pregnancy. While some families know that they have a history of a disease that is passed on in an autosomal recessive way, others may not.
Preimplantation testing can find genetic changes in embryos made using assisted reproductive techniques (ART), like in vitro fertilization (IVF). Your provider takes a small number of cells from the embryos and tests them for certain changes. This way, you can make an informed choice about which embryos your provider will implant in your uterus to start a pregnancy.
Newborn screening tests for certain genetic, metabolic or hormone-related conditions. Healthcare providers screen all newborns immediately after birth so treatment can start as soon as possible if they need it. In the U.S., hospitals can screen for up to 80 different medical conditions. Each state decides which diseases to screen for in newborns.
Your healthcare provider can sometimes use predictive and pre-symptomatic tests to look for genetic changes that increase your likelihood of developing a condition later in life. These include certain types of cancer. Genetic predisposition tests like BRCA testing look for mutations in the BRCA genes. Mutations in these genes can mean an increased risk of breast cancer and other cancers.
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Pre-symptomatic tests can tell whether you’ll develop a genetic disease before you’ve had any symptoms. But not always with 100% certainty. So, speak with your provider about the risks and benefits.
Pharmacogenomics is a type of testing that looks for changes in your genetic makeup that may affect how your body processes certain medications. The test determines if a medication will work for you. If the test shows it will work, it can also predict the safest and most effective dose. This helps your healthcare provider choose the best treatment options for you.
It’s important to remember that while gene testing can find some conditions, it doesn’t detect everything. Also, a positive result doesn’t always mean you’ll develop a disease. But DNA tests can be useful to confirm or rule out many different diseases and conditions. These conditions include:
Your healthcare provider will collect a sample of your blood, hair, skin, tissue or amniotic fluid. They’ll send the sample to a laboratory.
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At the lab, a pathologist will look for changes in your genes, chromosomes and DNA. Then, they’ll send the test results to your provider.
The physical risks of most DNA tests are small. Certain types of prenatal testing do carry a small risk of infection, bleeding and losing your pregnancy (miscarriage). This is because the test requires collecting a sample of amniotic fluid from around the fetus.
The greater risks of gene testing are emotional and financial. If you receive unexpected results, you may feel angry, scared, depressed, anxious or guilty. Also, gene testing can cost anywhere from hundreds to thousands of dollars. Insurance may cover the cost of gene testing, but it often depends on the type of test and the reason for it.
Gene testing doesn’t provide information about all possible genetic disorders either. And not all of them are 100% accurate. They also don’t necessarily tell you about how severe symptoms may be. And they don’t tell you when a certain genetic condition may develop.
Genetic testing results can sometimes also have implications for your ability to obtain certain types of insurance. Your genetic counselor should walk you through any of those concerns.
The results of DNA tests aren’t always straightforward. Your healthcare provider will use the type of test, your medical history and your family history to interpret them. Then, they’ll go over the specific results with you. The results may be any of the following:
Two measures of accuracy apply to gene testing:
All labs that perform DNA tests that a genetic counselor or geneticist would recommend are regulated by federal and/or state standards. The standards are designed to ensure the accuracy of gene testing. Some direct-to-consumer (DTC) genetic testing companies don’t follow these same regulations.
Some test results may only take a few days. Other tests can take several weeks to a month or two. Your healthcare provider will give you specific information regarding the timing of your test results.
If a test result comes back positive, speak with your healthcare provider or a genetic counselor. They can further explain the results and provide you with next steps. Depending on the condition, your provider may request additional tests to learn more about the disease and determine treatment options.
Your provider may refer you to a specialist who’s an expert in the condition and can answer specific questions. Or you may work with a social worker, who’ll listen to your concerns and help guide you through the process.
You should try to find a healthcare provider or genetic counselor near you to perform gene testing. They’ll order the correct tests and then talk to you about what they mean.
Direct-to-consumer (DTC) genetic tests are risky if you don’t have anyone you can speak to personally about the results.
Scientists discovered a technique called “restriction fragment length polymorphism (RFLP)” analysis in the 1980s. This analysis became the first genetic test to use DNA. But in the 1990s, polymerase chain reaction (PCR) testing was introduced. This type of gene testing replaced RFLP testing. The science of gene testing is constantly changing.
A DNA paternity test can determine a child’s biological father. You can figure out whether someone could be the biological father of your baby or child through a DNA cheek swab or blood test.
DNA tests (gene tests) can help you determine if you have a genetic condition or if you’re more likely to develop one. Gene testing may give you peace of mind, but it also comes with risks and limitations. If you’re interested in taking a DNA test, call your healthcare provider. They can refer you to a genetic counselor to give you more information about the process.
Do certain health conditions seem to run in your family? Are you ready to find out if you’re at risk? Cleveland Clinic’s genetics team can help.
Last reviewed on 05/28/2025.
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