Testing for genetic conditions

The Genetic Testing Registry (GTR) provides a central location for providers to submit genetic test information. The goal of the Registry is to advance the public health and research into the genetic basis of health and disease.

Screening and diagnostic testing: What’s the difference?
Screening is used to find those people who have a higher risk for a certain condition. It is sometimes done before a diagnostic test, like in the case of prenatal screening. If a screening result is abnormal, it does not necessarily mean that the person is affected with the condition. It means that diagnostic testing is needed to see if there really is a problem.

Genetic Testing

Genetic testing searches for changes, or mutations, in your genes that may cause a medical problem.

There are many types of genetic tests. These tests may help your family or your doctor make healthcare choices in different situations:

  • Carrier screening checks if a person is a carrier for a genetic disease. Most carriers do not show any signs or symptoms of the disease they are a carrier for.
  • Diagnostic testing can check for specific, known genetic conditions.
  • Newborn screening checks for certain treatable conditions at birth.
  • Pharmacogenomic testing can help doctors figure out what medicine to give you and how much medicine to give.
  • Predictive testing can determine if you are at risk for developing a genetic condition later in life.
  • Pregnancy related testing includes all of the possible testing that can be done during a pregnancy to check for any increased risk for genetic or other health conditions.

Before having a genetic test, think about talking to a genetic counselor. Genetic counselors can tell you and your family about important factors to consider when thinking about genetic testing. They also can explain how the particular test you are having may affect your life depending on the results.

Testing Procedure

To do a genetic test, you need a sample of blood, saliva, hair, skin, amniotic fluid, or other tissue. Different tests use different types of samples. Your doctor will decide which sample will be used. Scientists use the sample to check for specific genetic changes. The tests might check your DNA, RNA, chromosomes, proteins or metabolites for these changes.

In some cases you may need several genetic tests. For example, some genetic conditions are caused by more than one genetic change.

Test Results

When you receive your test results, they may be hard to understand. A genetic specialist can help explain your results to you and your doctor and help you think about next steps. For example, if you have a genetic condition, you may want to start seeing a specialist to help manage your condition. See the Specialist section for more information. Other members of your family may want to be tested, too. Check out the Genes and Your Health section for more information about how genetic conditions can run in your family.

Possible Benefits of Genetic Testing

You may benefit from genetic testing whether the results are positive or negative for a gene change, or mutation. For some people knowing the results either way may provide a sense of relief. Whatever the results, you and your family can better prepare for the road ahead.

Possible Risks of Genetic Testing

Genetic testing usually has a very low risk of affecting your physical health. But genetic testing can sometimes affect your emotional or financial well-being. Some people may feel angry, depressed, anxious, or guilty about their results. In some cases, genetic testing creates tension within a family. Each person's experiences are unique, so it is difficult to guess what your experience will be like based on someone else. See Genes and Your Health for more information.

Discrimination by others based on your genetic test results is also a possible risk. Congress enacted the Genetic Information Nondiscrimination Act (GINA) in 2008 to protect people from genetic discrimination. This law added to the protections many states already had in place. Today it is illegal for you to be treated differently by your employer or health insurance provider because of a genetic mutation.

GINA does not prevent long-term care, disability or life insurance providers from using genetic test results to make decisions about your coverage. Refer to GINAhelp.org or the Genetics Home Reference for additional information on genetic discrimination.

Genetic testing does have some limitations. What a genetic test may not tell you depends on the specific test. A genetic counselor can explain the limitations of the test that you are having.

The Cost of Testing

A genetic test may cost anywhere from $100 to more than $4,000, depending on the test. Your health insurance plan may cover all or part of the cost of genetic testing. Check with your health insurance provider to see if coverage is available.

Information on this webpage is adapted in large part from:

The Genetics Home Reference [Internet] Bethesda: National Institutes of Health; c2011. Handbook: Genetic Testing; 24 Oct 2011 [cited 27 Oct 2011]. Available at http://ghr.nlm.nih.gov/handbook/testing.