Genetic Testing FAQ: Everything you need to know

Even in 2024, genetic testing has a futuristic feel: the power to open up our cells and read out exactly what makes us who we are. Now, it’s common – and not very expensive – to harness this power from the comfort of your couch in a matter of weeks.

While it might be common, it’s still not exactly clear to many what genetic tests measure or how they work. From broad questions to the nitty-gritty details, we’ve got you covered. This FAQ discusses everything you need to know about genetic testing to make an informed decision for yourself.

Your DNA drives every cell in your body. Genetic testing is how we read that DNA to understand what our body does. It looks for changes and variations called mutations within the code that make you who you are. These can be as small as one-nucleotide (A, C, T, or G) change or changing part of, or entire, chromosomes. Some of these mutations are good. Some are bad, and most have no real consequences.

Genetic tests are tools that can help you and your medical providers understand:

• If you have a genetic condition or cancer
• If you are at risk for disease
• If you are a carrier for a genetic condition that you might pass on to a child
• Your relationship to the people around you
• Your predispositions to everyday things like muscle building, sleep, and caffeine

In clinical settings, genetic testing refers to a test for one specific gene – BRCA1 or BRCA2, for example, which are well-known genes that can increase your risk of developing breast and ovarian cancer.1 However, in day-to-day conversation, genetic testing also includes panel tests, which look at several different genes at once, and ancestry tests, which can help determine where you’re from.

Technically, genetic testing is an umbrella term that includes things like DNA testing. Genetic testing refers to testing all of your genes (also called genomic testing), while DNA testing typically looks at a smaller number of genes (coded in DNA) that we know often mutate. There are other types of testing too, including:

• RNA testing
• Mitochondrial DNA testing
• Exome testing
• Genomic testing
• Chromosomal tests
• Karyotypes (which measure all of your chromosomes)
• Epigenetic tests
• Gene expression/mRNA tests

It can get confusing because not every study or organization relies on these same rules. Many people use “DNA testing” and “genetic testing” interchangeably. This FAQ uses “genetic testing” to cover a broader range of tests.

Genomic testing looks at your entire genome: all of your genetic information on every chromosome. It doesn’t narrow its focus on one or a handful of locations like genetic testing often does.2 You might see genomic testing called “DNA sequencing,” often used to identify points of concern in cancer treatment, though it’s starting to creep into at-home testing for curious minds.

There is also a specialized version of genomic testing called exome testing. Rather than reading all of the billions of alleles in your DNA, it looks specifically at the sites we know code for variable genes, like eye color or kidney function, rather than the DNA that doesn’t change between people. After all, we are 99.9% alike: it’s that 0.1% difference that separates us from our neighbors, friends, and strangers across the globe.3 Exome testing offers a more streamlined approach – often at a lower cost – without missing the essential parts of genomic testing.

Epigenetics is a relatively new field of genetics that became popular in the 1990s. It looks at how your behavior and the environment influence your genetics.4

Epigenetics relies on different biochemical processes that sit above your DNA strands. First, chemical groups turn different parts of your genes on and off. These chemical groups either allow or prevent your cells from reading and replicating that piece of DNA. It’s easy to think of epigenetics like light switches: they are small, reversible changes that influence how your body reads your genes. They don’t permanently change the genes themselves. These chemical groups include:

• Methyl groups, the most common type of epigenetic change (methylation/demethylation)
• Histone modification (a protein wrapped around the DNA to make it unreadable)
• Non-coding RNA (which breaks down pieces of genetic information that code)

Virtually everything you do in life can alter your epigenetics, from aging to picking a place to live. Your diet, exercise, and substance use patterns have a hefty hand in epigenetic changes as well. It’s believed that type 1 diabetes, one of the most inheritable autoimmune diseases, happens on an epigenetic level after a virus changes your DNA methylation and non-coding RNA for insulin-producing pancreatic cells.5

While you sadly might not be able to undo the start of type 1 diabetes, many epigenetic changes are reversible. For example, a 2019 study showed that rheumatoid arthritis might be induced by epigenetic changes that are fully reversible before the disease begins to set in.6

Single nucleotide polymorphisms, or SNPs (pronounced snips), are a normal type of genetic variation. They occur when a single nucleotide (half of a base pair) changes to something new, such as changing adenosine (A) to guanine (G). This mutation might be harmful, neutral, or beneficial for our daily lives. Most human SNPs are relatively neutral, occurring not in a gene itself but in the genetic coding around a gene.

The average person has between four and five million SNPs in their entire genome.7 When you take a genetic test, there’s a strong likelihood that the test itself is measuring variation in genes that commonly have SNPs. After all, 9 of the top 10 leading causes of death in the United States have some kind of genetic component.

The specifics of a genetic test depend on the test itself. With a genetic panel test like most at-home testing uses, the test looks at common spots within your genes for SNPs. This will tell the researchers whether your gene codes for the “average” or common allele or a less-common variant.

One common gene with a simple explanation is the COMT gene. This gene codes for an enzyme that breaks down dopamine and norepinephrine in your brain, two common neurotransmitters that help control stress, pleasure, and focus. The most common COMT gene reads A/G – adenosine base pairs with guanine in a normal fashion and helps your brain break down the neurotransmitters at an acceptable pace. However, your gene may be different:

• G/G (fast COMT) breaks down neurotransmitters faster and is relatively common.
• A/A (slow COMT) breaks down neurotransmitters slower.

This slower breakdown in slow COMT means it can take longer to get out of “fight or flight” mode in stressful situations. Slow COMT is also associated with higher neuroticism, anxiety, bipolar disorder, and schizophrenia. However, it also means you’re more likely to experience more pleasure in happy moments.8 By looking at these single base pairs, the genetic test can help you understand how your neurotransmitters – and, in this case, emotions – work.

Other types of genetic tests measure different features. A karyotype, for example, measures the size, shape, and number of chromosomes in your body.

For the most part, genetic tests are accurate. Exactly how accurate varies depending on the exact test you take. One of the most significant ways to guarantee it will be (at least relatively) accurate is whether or not it’s been approved by the FDA. Right now, only one at-home genetic test has been: 23andMe. More tests seem to be in the pipeline for FDA approval, however.

If you’re looking for an accurate genetic test that’s not 23andMe, you’re not out of luck. A laboratory standard called CLIA (the Clinical Laboratory Improvement Amendments) guarantees high-quality testing.9 Labs that work with humans and human information can be CLIA-certified, meaning they meet or exceed the quality, privacy, and safety standards set by the Centers for Medicare and Medicaid Services. A CLIA-certified lab undergoes rigorous testing and is guaranteed to have at least a moderately high level of accuracy in their results. Many genetic tests work with CLIA-certified labs, so you’ll have your pick of the best.

Race, ethnicity, and accuracy problems

The type of test that you take can change the accuracy of your results. Genealogy tests are less accurate than health- or lifestyle-based tests because there aren’t specific genes associated with different countries, regions, or ethnicities.

Genealogy tests are fully dependent on “libraries” of information associated with people from different regions. Suppose someone is looking for their European background. Because more people with European backgrounds have taken genealogy tests, they’re more likely to find high-level information than someone looking into their African or Indigenous heritage. Fewer people with African or Indigenous backgrounds have taken these tests, so their “libraries” do not contain as much detail. This is why these tests can often determine the difference between two European groups like “Irish” and “Welsh” but not two Indigenous groups like “Lakota” and “Anishinaabe.”

However, genetic tests for health or lifestyle concerns have well-researched information about the phenotypes many SNPs are associated with. Sometimes genetic tests can misinterpret results, overpromising things like an “overachiever gene” tied to a neurotic personality. Still, they are more likely to be both stable and accurate over time and across tests.

Even genetic health tests, however, can sometimes miss critical genetic changes. A 2021 study from JAMA Cardiology compared the results of a doctor-ordered screening with an at-home genetic test and found that the at-home test missed important results in about:

• 62% of total study participants
• 94% of Black participants
• 84% of Hispanic participants
• 33% of Ashkenazi Jewish participants10

There’s a lot of work still to be done to make genetic tests accurate for people without white European ancestry. But identifying these spots as problems means that we can work to make them better in the near future.

Genetic tests can tell you what genes you have, but not much more. In most cases, they can’t tell you:

• If you’ll develop a disease
• When you’ll develop a disease
• Exactly where your family comes from
• Your risk of every condition

Some genes and their variations are correlated with increased vitamin absorption or protein production levels, but it’s just that: a correlation. Nothing you read in a genetic test, even in one ordered by a doctor, is necessarily a guarantee. Your genes interact with the environment and your daily choices – both in your epigenetics and in just making the right choices – to create your future.

Genetic science is constantly evolving and growing. The full human genome was finally decoded in 2021. The announcement that it was completed in 2000 was a bit of a stretch since it missed 15% of repeating sequences and other things that technology couldn’t achieve yet.11

We know that Huntington’s Disease is caused by a repeat sequence, meaning that one 3-nucleotide sequence (CAG) repeats too many times. If you have 40 or more of the repeat sequence, you’re sure to develop the disease.12 In that case, your genetic information can be used as a diagnostic tool.

On the other hand, we might find five, ten, or 50 years down the road that there’s a lot of knowledge about our genetics that we just don’t have access to right now. Eye color, for example, was first thought of as a simple one-gene phenotype, but we now know it actually comes from 61 separate genes.13

So, what about your at-home genetic test? You can guarantee that you have the genes that they’ve tested and that, if they’re a CLIA-certified lab, the findings are probably accurate. You might learn that you have a higher risk of developing a disease or kinks in a biological pathway, meaning you’ll need to watch what you eat. But you won’t learn exactly when, how, or if that pathway will manifest into something worse.

Right now, the main use of genetic testing at home (not in a doctor’s office or prescribed by a doctor) is to learn more about yourself. Whether you’re driven by the curiosity of finding potential family or whether your body metabolizes caffeine quickly, you can learn dozens of interesting insights about where you come from and what you’re predisposed to.

At-home genetic testing can also help you stay vigilant and proactive about potential health issues. Suppose you learn that your genetics predispose you to higher levels of LDL (“bad” cholesterol) and lower levels of HDL (“good” cholesterol), whether or not your cholesterol levels reflect that finding. In that case, you can make sure to take measures early, such as reducing saturated fats and increasing fiber in your diet, to offset your risk.

Similarly, imagine learning that you carry a harmful BRCA1 or BRCA2 mutation, which can dramatically increase your risk of breast and ovarian cancer.14 This means you’ll have the knowledge to have cancer screenings more often and, in some cases, choose to have preventative surgeries like a double mastectomy or hysterectomy.

FDA regulation and applications

Almost all of the non-genealogy genetic tests on the market right now are for “lifestyle and entertainment” rather than health or medical tests. This is because the tests need to be registered with and approved by the FDA to legally give you medical advice or insights. The only test that has FDA recognition right now is 23andMe.15

After getting a warning letter for advertising health and medical benefits without FDA approval, the company underwent a major overhaul and was re-released in 2015. Even within 23andMe, each genetic condition they test for needs separate FDA approval, meaning the approval process is still very slow. For example, since their 2015 rebrand, 23andMe has been able to provide tests for:

• Late-Onset Alzheimer’s Disease (2017)
• Parkinson’s Disease (2017)
• Hereditary Thrombophilia (2017)
• Alpha-1 Antitrypsin Deficiency (2017)
• Gaucher’s Disease (2017)
• BRCA1 (2018)
• BRCA2 (2018)
• MUTHY-associated polyposis / hereditary colorectal cancer (2019)16

Not having FDA approval isn’t necessarily a sign that a test is bad or doesn’t work. Most vitamin supplements don’t have FDA approval, but many still find that they help improve symptoms related to vitamin deficiencies. So, if you do a genetic test, know that it’s not a diagnostic test nor something you should take advice from, but it can still provide you with accurate results.

There’s no wrong time to take a look at what makes you who you are. Your genetics are the same throughout your life (except for epigenetics), so there’s no rush to look before they go bad. Whether you feel good or bad, your genes will show the same information.

However, since there are some situations where your genetic findings might be shocking or upsetting, it’s important to be psychologically prepared for anything to come up. Be sure to familiarize yourself with the genetic test you’re taking: what does it test for? What results might you expect? Some tests – like paternity – can have life-changing implications if you discover things aren’t what you’d anticipated.

On testing day

Some tests will ask that you take them first thing in the morning before you eat or not to eat, drink, or smoke within an hour of taking the test. This is to prevent your sample from being contaminated by other particles – imagine taking a DNA test and it showing that you’re half strawberry because you ate breakfast before taking the test.

Other tests request that you take and send them in early in the day Monday through Thursday so that the mail doesn’t sit out too long and they can receive the package without having to wait over the weekend. However, since your genetics don’t change, most genetic tests don’t require you to take them at any specific time or on a specific day.

Before you take a genetic test, it’s important to know that it could bring up shocking information, such as your risk for developing early-onset Alzheimers or that your family isn’t who you think they are. Being aware of this risk can help you decide whether you’re ready to test your genetics.

Either way, surprises can sneak up on you. Should you learn that you have a gene that predisposes you to cancer or a degenerative disorder, it might shake you. That’s where genetic counselors come in. A genetic counselor is a specialist with a Master’s degree who helps you interpret, understand, and plan your genetic testing results and next steps. They will order follow-up testing to ensure that the first test is correct and can connect you with doctors and specialists in the field to get you help.

The National Society of Genetic Counselors has a great database of all licensed genetic counselors in the United States and Canada to help find someone near you.

If your discovery startles you, it’s always helpful to talk out your feelings with a counselor. (We’ve picked out the best online therapy providers who might be able to help you process.) They can help you stay grounded while you explore your options, no matter if it’s changing your diet, preventative surgery, or suing a hospital for medical malpractice during IVF.

There’s nothing that says you can’t see a genetic counselor and take a genetic test at home. In fact, there’s some benefit to having a genetic counselor go over your results with you, particularly if you have questions or concerns. If you’re not sure that the time or financial investment in genetic counseling is right for your situation, here are some of the best reasons to seek genetic counseling:

• Cancer risk, diagnosis, or treatment planning
• Family history of genetic disease
• Fertility testing
• Prenatal testing
• Genetic testing for specific diseases, especially if they’re uncommon
• When required by medical practitioners or for things like IVF
• Needing guidance or advice from someone with medical knowledge about your genetics
• Interested in detailed explanations of your results
• Need verification on a positive (or negative) result

On the other hand, if your motivations are driven by curiosity or are generally simpler, an at-home test might fill your needs in less time and for less money. Other simple things that at-home tests can inform you about include:

• Interested in ancestry or genealogy
• Paternity testing
• Lifestyle improvements

If you’re struggling to get pregnant and the go-to tests aren’t telling you why, you can use a genetic test to see if your fertility problems are genetic. This might mean that you have a chromosome abnormality or are intersex and do not know it. Likewise, if you’ve had multiple miscarriages, there may be an underlying genetic reason.

Some of the genetic tests to check for infertility include:

• Karyotyping (looking at full pictures of all of your chromosomes for whole and partial chromosomal aberrations)
• Chromosomal deletions (especially on the Y chromosome)
• Single gene analysis and panels (such as the CFTR gene for cystic fibrosis)

Genetic abnormalities are more likely to cause infertility in people assigned male at birth. However, it can be useful to find genetic syndromes in people assigned female at birth struggling with fertility.17 Most, if not all, of these tests should be ordered by a reproductive endocrinologist, OB/GYN, or genetic counselor.

Simple genetic panel screenings for carriers are also common prenatally. These tests look at genetic diseases and disorders that you could pass down to a child, even if you don’t have symptoms. They don’t have as much to do with fertility itself but are an essential step to ensuring that you have a happy, healthy baby. These prenatal screenings are widespread and are often required for IVF, sperm donation, and other prenatal situations.

While a fetus is developing, genetic testing helps understand what congenital disabilities or major genetic disorders the child may have at birth. Not everyone has the chance to do prenatal genetic testing to look at things like carrier status for diseases. Still, many more people have the opportunity to check in before the baby’s born.

There are opportunities for genetic tests for both the parent and the baby. After you know you’re pregnant, a series of genetic tests can be – but aren’t always – performed at different stages of your pregnancy, depending on fetal development.

Other common genetic disorders that these tests look for include:

• Cystic fibrosis
• Duchenne muscular dystrophy
• Hemophilia A
• Polycystic kidney disease
• Sickle cell disease
• Tay-Sachs disease
• Thalassemia

You can also take several genetic tests as a parent before the baby’s born. A study from early 2022 suggests that people pregnant with twins should have genetic testing for vascular Ehler-Danlos syndrome (vEDS) because people with vEDS have a high risk of dying during a twin pregnancy if not carefully monitored.18 In some cases, genetic testing can save your life.

Genetic testing to assist in psychiatric care is new and up-and-coming. These tests look at the genetics behind your pharmacokinetics and pharmacodynamics. Pharmacokinetics is how drugs move within your body, and pharmacodynamics is how the drugs affect your body.

Mental health genetic testing, then, analyzes how your brain creates, sends, uptakes, reuptakes, and absorbs neurotransmitters that are commonly askew in psychiatric conditions. This allows psychiatrists to best understand where your symptoms are coming from and then prescribe a medication that’ll fit best, removing the heinous trial-and-error period for psychiatric medication.

Genetic testing cannot yet diagnose mental health concerns. While they are often heritable disorders – major depression, for example, has a 40-50% heritability rate19 – developing a mental illness, like any other disease or disorder, isn’t solely based on your genetics. For example, having a predisposition toward high cholesterol doesn’t mean you’ll eventually need to go on statin medications. Likewise, having a predisposition toward anxiety or schizophrenia doesn’t mean that you’ll necessarily develop it.

Right now, genetic testing for mental health is something that only psychiatrists or other health professionals can order for you. Few tests have FDA approval and may not be prescriptive, but it seems promising that this field will grow with time.

Every testing company has a different privacy policy and terms for sharing your information. For the most part, companies won’t share your private medical info. They de-identify and anonymize your genetic information before sharing it with a lab for analysis or research purposes. This means that it won’t be tied to your name, address, credit card, or social security number (if you shared that). Researchers won’t know whose genetic information they’re studying.

A handful of states, including California, have started to pass laws regulating what at-home genetic testing companies tell you about their privacy, security, and consent standards.20 Your privacy rights are also protected under GINA, the Genetic Information Nondiscrimination Act of 2008.

One important thing to note: if you download your genetic information from an at-home testing company and upload it to another company, the company that originally collected your genetic information is no longer responsible for any privacy breaches that may occur.21 For example, if you transfer your info from AncestryDNA to another genetic testing company for a discounted analysis price, AncestryDNA is no longer responsible for keeping your genetic information private.

Some other options you have to protect your privacy with DNA testing involves minimizing the amount of personal information you share upfront:

• Sign up with an encrypted email address
• Use a VPN to protect your IP address
• Use a PO Box to receive your testing kit
• Pay with a preloaded credit card
• Respond only to required survey questions

Not at all. Several different laws specifically prevent this from happening.

GINA, or the Genetic Information Nondiscrimination Act of 2008, is the most significant piece of legislation that protects your right to know your genetic information.22 It was passed federally, meaning that it applies to every citizen of the United States. Specifically, GINA prevents employment and health insurance coverage discrimination. A health insurance company cannot:

• Require you to submit genetic information to be approved for eligibility, coverage, underwriting, or premium-setting decisions
• Use your genetic information to decide your enrollment or coverage
• Require you to take a genetic test
• Use genetic information as a pre-existing condition, but only in Medicare

GINA doesn’t protect you against life, disability, or long-term care insurance discrimination. However, the ADA (American Disability Act) was updated to include symptomatic genetic disabilities as protected disabilities. The disability needs to be symptomatic and actively affecting your life, though: a 2019 Supreme Court case ruled that just having a genetic predisposition doesn’t count under the ADA.23

GINA also prevents your employer from discriminating against you using your genetic information. This includes:

• Using your genetic information to make any hiring, promotion, privilege, pay, or termination decisions
• Limiting, segregating, classifying, or depriving you of employment opportunities based on your genetic information
• Requiring you to submit your genetic information (unless publicly available)
• Expelling you from a union or labor organization based on your genetic information

Most states have also taken on additional laws that protect your genetic information. We’ve put together a chart that helps you understand the breakdown of which states protect the most – and least – of your genetic information. These laws are additional statutes alongside, but never instead of, GINA; states without any additional laws are still protected federally. We’ve ordered the states alphabetically, so scroll to find yours.

The average cost of an at-home genetic test dropped significantly between 2008-2012 and continues to decline.24 That said, it still costs anywhere from $100 to over $2,000 for one genetic test. The cost of testing varies dramatically depending on:

• The company
• The scale of testing
• The scope of testing
• Testing frequency
• Test complexity
• New test technology

Right now, there are some cases where health insurance covers the cost of genetic testing when ordered by your doctor or a genetic counselor. Check with your provider before signing off on a multi-thousand-dollar test that you think will be covered.

At-home genetic tests are rarely covered, but some insurance policies allow reimbursement. Again, check in with your insurance before committing to a big purchase like a genetic test if you want to get reimbursed.

HSA and FSA payments

A 2019 ruling from the IRS states that you can use some of your FSA or HSA funds to cover the cost of some 23andMe tests. Right now, this is only applicable to 23andMe since they are the only at-home genetic test approved by the FDA, but this is likely to change as other tests get approval. It’s not easy to determine which packages are covered, but 23andMe put together a handy calculator to help you figure it out.