Overview
Genetic testing examines DNA, genes, or chromosomes to look for changes linked to health conditions or inherited traits. It may be used before symptoms begin, during evaluation of a health problem, during pregnancy, or after birth. Some tests check a single gene, while others examine many genes at once. The meaning of a result depends on the reason for testing and the person's personal and family history.
Causes and Risk Factors
People may consider genetic testing because of a strong family history of a condition, a relative with a known genetic variant, unusual symptoms, repeated pregnancy losses, or concerns during pregnancy. Some populations have higher rates of certain inherited conditions because of ancestry or community history. In many cases, testing is offered when a healthcare professional thinks the result could help guide care or clarify risk.
Who Is Affected
People of any age, sex, or background may have genetic testing, depending on the reason. Newborns may have screening tests shortly after birth, adults may seek testing for inherited cancer or heart disease risk, and couples may have carrier screening before or during pregnancy. Families affected by rare diseases are often referred for genetic evaluation.
Prevention
Genetic testing itself does not prevent disease, but in some situations it can help people understand risk earlier and plan monitoring or family decisions. Not every condition can be predicted or prevented with testing. Before testing, it is helpful to discuss what the results can and cannot tell you, whether the findings could affect relatives, and how privacy and data storage are handled.
Diagnosis and Tests
Testing may use a blood sample, saliva, cheek swab, or other tissue, depending on the type of test. Common categories include diagnostic testing, predictive or presymptomatic testing, carrier screening, prenatal testing, newborn screening, pharmacogenomic testing, and tumor testing. Results may be reported as positive, negative, or uncertain, sometimes called a variant of uncertain significance. Because interpretation can be complicated, results are often reviewed with a genetics-trained professional.
Treatment Categories
Genetic testing is a tool for information, not a treatment by itself. In some cases, results may help guide monitoring, screening, reproductive planning, referrals to specialists, or choices about medicines or procedures. Sometimes testing does not change care, especially if the result is uncertain or if no specific management approach exists for the condition.
Living With It
Waiting for results or learning about inherited risk can bring stress, guilt, confusion, or family tension. Some people feel relief from having an explanation, while others may struggle with uncertainty. Support from healthcare professionals, genetic counselors, trusted family members, or patient groups may help people understand the information and make decisions over time.
When to Seek Medical Care
Speak with a healthcare professional if you have a strong family history of early cancer, sudden unexplained death, inherited heart problems, repeated miscarriages, a child with developmental differences or multiple birth differences, or a relative with a known genetic condition. Also seek guidance if you received a direct-to-consumer genetic test result that you do not understand. Medical confirmation may be needed before any health decisions are made.
Questions to Ask a Healthcare Professional
Ask why the test is being recommended, what type of result is possible, and how the result could change medical care. You can also ask about the limits of the test, whether family members may need testing, how your sample and data will be stored, and whether genetic counseling is available. If cost matters, ask about insurance coverage, out-of-pocket charges, and possible alternatives.