Genetic testing for disease risk is worth doing when the result can change your care: a strong family history of certain cancers, very high cholesterol at a young age, or a relative who already carries a known variant. For most other people, and especially with at-home kits, the results are narrow and easy to misread. Here’s what these tests can and can’t tell you, where they make a real difference, and how to protect your DNA data.
What Genetic Testing for Disease Risk Can and Can’t Tell You
A predictive genetic test looks for inherited changes in your DNA, called variants, that are known to raise the risk of a specific disease. It gives you one of three answers. A positive result means a harmful variant was found: your risk is higher, but it’s a probability, not a diagnosis. A negative result only covers the genes and variants the lab actually checked.
The third answer surprises many people: a variant of uncertain significance, or VUS. The lab found a change but doesn’t yet know whether it matters. Large multigene panels return these often, and most are later reclassified as harmless. A VUS should never drive a medical decision on its own.
Then there’s what testing can’t do. Common conditions like type 2 diabetes, most heart disease and most cancers come from many genes interacting with age, lifestyle and environment. Polygenic risk scores try to capture that mix, but in 2026 they’re still a research tool rather than a standard part of medical care.
Clinical Genetic Tests vs Direct-to-Consumer Kits
Not all genetic tests answer the same question. The type of test, and who orders it, decides how far you can trust the result.
| Test type | What it looks for | Who orders it | Example |
|---|---|---|---|
| Diagnostic test | Confirms or rules out a genetic condition in someone with symptoms | Doctor or specialist | Cardiomyopathy gene panel after an abnormal heart scan |
| Predictive test | Inherited variants that raise future disease risk | Doctor, usually with genetic counseling | BRCA1 and BRCA2 testing after breast or ovarian cancer in the family |
| Carrier screening | Variants you could pass on to your children | Obstetrician or fertility clinic | Cystic fibrosis or spinal muscular atrophy screening before pregnancy |
| Pharmacogenomic test | Genes that change how you respond to drugs | Doctor or pharmacist | CYP2C19 testing before prescribing clopidogrel |
| Direct-to-consumer kit | A limited set of variants, plus ancestry and traits | You, no prescription | 23andMe BRCA report covering 3 variants, FDA-authorized in 2018 |
That last row deserves attention. The 2018 FDA authorization covered three BRCA variants that are most common in people of Ashkenazi Jewish ancestry, while thousands of other harmful BRCA variants exist. A clean consumer report doesn’t clear you. Raw-data interpretation services are even shakier: a 2018 study in Genetics in Medicine found that about 40% of variants flagged in consumer raw data were not confirmed by clinical testing. Any health finding from a consumer kit needs confirmation in a clinical lab before anyone acts on it.
Where Testing Actually Changes Your Care
The three conditions the CDC ranks highest
The CDC classifies three inherited conditions as Tier 1 genomic applications, meaning the evidence clearly shows that finding them saves lives:
- Hereditary breast and ovarian cancer (BRCA1 and BRCA2). The National Cancer Institute estimates a lifetime breast cancer risk of 55 to 72% for BRCA1 carriers and 45 to 69% for BRCA2 carriers, against about 13% in the general population. Carriers can start MRI screening earlier and consider risk-reducing medication or surgery.
- Lynch syndrome. It affects roughly 1 in 280 people and sharply raises the risk of colorectal and endometrial cancer. Colonoscopies starting in your 20s or 30s, typically every one to two years, catch polyps before they turn into cancer.
- Familial hypercholesterolemia. About 1 in 250 people are born with very high LDL cholesterol, and most of them don’t know it. Starting a statin early dramatically lowers the risk of a heart attack in your 30s or 40s.
These results also matter for your relatives. When one person tests positive, parents, siblings and children can be tested for that single known variant, a process called cascade testing. It’s faster, cheaper and more reliable than a broad panel, and it’s where genetic testing does the most good in practice.
Pharmacogenomics: matching drugs to your genes
Some genetic tests don’t predict disease at all. They predict how you’ll react to a medication. Screening for HLA-B*57:01 before prescribing the HIV drug abacavir prevents a dangerous hypersensitivity reaction. Clopidogrel, a common blood thinner, carries an FDA boxed warning because it works poorly in people whose CYP2C19 gene breaks it down slowly. Testing TPMT and NUDT15 before thiopurine drugs helps avoid severe bone marrow toxicity.
Pharmacogenomic results stay valid for life, so one test can guide prescriptions for decades. Ask your doctor whether it makes sense before starting a long-term treatment known to have gene-drug interactions.
Why Genetic Counseling Matters Before and After the Test
Informed consent for a genetic test goes further than signing a form. Before testing, you should understand which genes will be checked, what each possible result would mean for you and your family, and who will have access to the data. A genetic counselor walks you through exactly that, and helps you decide whether testing makes sense at all.
After the test, the counselor translates the report into decisions: which screenings to start, which relatives to inform, and what a VUS does or doesn’t change. Many insurers require counseling before they’ll cover hereditary cancer testing. The National Society of Genetic Counselors runs a free online directory, and many counselors now offer sessions by video.
Who Can See Your DNA Data
HIPAA protects genetic results held by your doctors, hospitals and health insurers. It generally doesn’t cover consumer DNA companies. Their privacy policies and a patchwork of state laws decide what happens to your data, and policies can change when a company changes hands.
23andMe shows what’s at stake. In 2023, a credential-stuffing attack exposed data from about 6.9 million customer accounts, including ancestry information. The company filed for bankruptcy in March 2025, and in July 2025 its customer database was sold for $305 million to a nonprofit founded by its co-founder Anne Wojcicki, now called the 23andMe Research Institute. A coalition of 43 state attorneys general later reached an $18 million settlement over the breach.
If you use a consumer test, read the privacy policy before you spit in the tube, opt out of research sharing if you’re not comfortable with it, turn on two-factor authentication, and know how to delete your data and destroy your sample. Your DNA also reveals information about your relatives, who never agreed to the test.
Genetic Discrimination: What GINA Covers and What It Doesn’t
The Genetic Information Nondiscrimination Act of 2008, known as GINA, bars health insurers from using genetic information to decide eligibility or premiums. It also bars employers with 15 or more employees from using it to hire, fire or promote. That’s real protection, and it covers most working Americans.
The gaps are just as real. GINA doesn’t apply to life insurance, disability insurance or long-term care insurance, to employers with fewer than 15 employees, or to members of the US military. A few states go further: Florida, since 2020, bars life, disability and long-term care insurers from using genetic test results to deny or price coverage.
One practical consequence: if you plan to buy life or long-term care insurance, consider doing it before a predictive test rather than after. It’s one of the most useful pieces of advice a genetic counselor will give you, and one of the least known.
Should You Get Tested? Weighing the Benefits and Risks
The case for testing is strongest when your family history points to a specific condition, when a relative has already tested positive, or when you have unexplained early-onset disease. In those situations, a result can change screening, treatment and the choices of your whole family.
The emotional side is real but often overestimated. Research on people tested for hereditary cancer genes generally finds that distress rises after a positive result and settles within months for most, especially when counseling is part of the process. The harder question is practical: what would you do differently with the answer?
If the honest answer is nothing, testing can wait. If you have no family history and you’re simply curious, a consumer kit is fine for ancestry, but it isn’t a health screen and shouldn’t reassure you. And if cancer or early heart disease runs in your family, talk to your doctor about a referral to genetic counseling rather than ordering a kit online.
FAQ
Is genetic testing for disease risk covered by insurance?
Often, when you meet clinical criteria such as a strong family history. Under the Affordable Care Act, women whose personal or family history suggests a BRCA risk can get genetic counseling and, if appropriate, testing without cost sharing, following the USPSTF recommendation.
Can a genetic test tell me if I will get cancer?
No. A positive result means your risk is higher than average, not that cancer is certain. A negative result lowers your risk for the variants tested but doesn’t remove the risk that everyone has.
How accurate are at-home DNA tests for health risks?
They’re accurate for the few variants they report, but they check only a small fraction of known disease variants. Any health finding from a consumer kit or a raw-data analysis should be confirmed by a clinical laboratory.
Can my employer see my genetic test results?
Under GINA, employers with 15 or more employees can’t request, require or use your genetic information in employment decisions. The protection doesn’t extend to very small employers or to the US military.