Genetic testing and genetic counseling often come up together, but they are two different things. Genetic testing is a laboratory test that looks for specific changes in genes or chromosomes. Genetic counseling is a conversation, usually with a specially trained professional, that helps someone decide whether testing makes sense and what to do with the results afterward. This page is a general introduction to both. It is educational, not diagnostic, and it is not a substitute for meeting with a genetic counselor about a specific family history or test result.

What genetic testing involves

Most genetic tests use a small sample, often blood or a cheek swab, though saliva, skin, or other tissue can also be used. A laboratory examines the sample for changes in genes, proteins, or chromosomes that are linked to a disease or condition. The right test, and whether a test is even useful in a given situation, depends heavily on the question being asked, which is one reason testing is usually planned together with a clinician or genetic counselor rather than chosen alone.

A few broad categories of testing come up often in clinical genetics:

  • Diagnostic testing. Used to confirm or rule out a specific genetic condition in someone who already has signs or symptoms. Diagnostic testing can happen before birth or at any later point in life, though it is not available for every gene or every condition.
  • Carrier testing. Looks for a single copy of a gene change that would only cause a condition in someone who inherits two copies. It is often offered to people with a family history of a genetic disorder, or to couples planning a pregnancy, so they can understand the chance of passing a condition to a child. Our inheritance basics pages explain how that risk is worked out for different inheritance patterns.
  • Prenatal and newborn screening. Prenatal testing looks for genetic or chromosomal changes in a fetus when there is an increased risk of a disorder. Newborn screening happens shortly after birth and targets a specific, state-defined list of conditions that can be treated early in life, and it reaches the large majority of babies born in the United States.
  • Predictive and presymptomatic testing. Offered to someone with no current symptoms but with a family history of a condition, to see whether they carry a gene change that raises their future risk, or will eventually cause the condition itself.

Genetic testing has real benefits, including clearer information for medical decisions and, in some cases, earlier treatment. It also has limits. A result can come back inconclusive, it may not predict how severe a condition will be, and testing can raise practical concerns about cost or insurance even where legal protections exist. None of that is a reason to avoid testing on its own, but it is part of why counseling matters both before and after.

What a genetic counselor is

A genetic counselor is a healthcare professional with graduate-level training in both medical genetics and counseling. According to the National Society of Genetic Counselors, genetic counselors help people and families understand the medical, psychological, and family implications of a genetic condition, interpret personal and family history to estimate how likely a condition is to occur or recur, and support decisions around testing, prevention, and next steps.

A genetic counselor is not the same as a geneticist or any other physician. Genetic counselors are not medical doctors. They typically work alongside a referring doctor, such as an obstetrician, oncologist, or medical geneticist, as part of a broader care team. Their role is to translate genetic information into something a patient or family can actually use day to day, not to replace the diagnosis or treatment decisions made with a physician.

Genetic counselors also tend to specialize, much like other clinicians do. Common focus areas include prenatal care, pediatrics, cancer risk, neurology, cardiovascular conditions, and psychiatry, and many now see patients by telehealth as well as in person.

When someone might be referred for genetic counseling

There is no single trigger for a referral. A few situations come up often enough to be worth naming here.

  • A family history of a genetic condition. If a condition such as one described in our conditions library runs in a family, a counselor can help work out how it is likely inherited and who else might be at risk. Our inheritance basics pillar covers patterns like autosomal dominant and autosomal recessive inheritance in more detail.
  • An existing diagnosis. When someone, or a close relative, has already been diagnosed with a genetic condition, for example a disorder along the spectrum covered in our ectodermal dysplasia section or a neurogenetic condition such as Angelman syndrome, counseling can help explain what the diagnosis means for other family members and for future family planning.
  • Planning a pregnancy with known risk factors. This includes a condition that runs in either partner's family, a previous pregnancy or child affected by a birth defect or genetic condition, a history of multiple miscarriages or stillbirth, or questions related to assisted reproductive technology.
  • Findings during pregnancy or in a newborn. An abnormal prenatal screening or ultrasound result, or a flag from newborn screening, commonly leads to a counseling referral so the family understands what further testing can and cannot show.

Genetic counseling is not limited to pregnancy and childhood. Adults are commonly referred when a personal or family history suggests an inherited cancer syndrome, a heart condition such as familial hypercholesterolemia, or another late-onset inherited disorder.

What to expect from an appointment

A genetic counseling appointment usually starts with a detailed conversation about personal and family health history, sometimes going back three generations. The counselor uses that history, along with any existing test results, to estimate how likely it is that a condition is present or could affect other family members.

From there, the counselor typically explains which genetic tests, if any, could answer the specific question at hand, what each test can and cannot tell you, and what a given result would and would not change about care. If testing has already happened before the appointment, the conversation shifts to interpreting the result: what it means, what it does not mean, and what reasonable next steps look like, including whether other relatives might want to consider testing themselves.

Throughout, counseling is meant to be a two-way conversation rather than a lecture. Part of the counselor's role is helping a person or family think through the emotional and practical weight of a decision, not just the biology, and connecting them with other specialists, support groups, or advocacy organizations when that would help.

In practice, one appointment is rarely the end of the process. A family history reviewed today may lead to a referral for testing, and a test result tomorrow often leads back to another counseling conversation to make sense of it.

Genetic testing and genetic counseling can be useful at almost any stage of life, from before a pregnancy to well into adulthood. This page is general background, not a diagnostic tool, and it is not a substitute for a conversation with a genetic counselor or physician about a specific family history or result. Our glossary is a good starting point for terms used across this site.