The news came four years ago, at the end of a casual phone call. Bill’s family had always thought it was a freak coincidence that his father and grandfather both had ALS. But at the end of a catch-up, Bill’s brother revealed that he had a diagnosis too. The familial trend, it turned out, was linked to a genetic mutation. That meant Bill might also be at risk for the disease.

An ALS specialist ordered Bill a DNA test. While he waited for results, he applied for long-term-care insurance. If he ever developed ALS, Bill told me, he wanted to ensure that the care he would need as his nerve cells died and muscles atrophied wouldn’t strain the family finances. When Bill found out he had the mutation, he shared the news with his insurance agent, who dealt him another blow: “I don’t expect you to be approved,” he remembers her saying.

Bill doesn’t have ALS. He’s a healthy 60-year-old man who spends his weekends building his dream home by hand. A recent study of mutations like his suggests that his genetics increase his chances of developing ALS by about 25 percent, on average. Most ALS cases aren’t genetic at all. And yet, Bill felt like he was being treated as if he was already sick. (Bill asked to be identified by his first name only, because he hasn’t disclosed his situation to his employer and worried about facing blowback at work too.)

What happened to Bill, and to dozens of other people whose experiences have been documented by disease advocates and on social media, is perfectly legal. Gaps in the United States’ genetic-nondiscrimination law mean that life, long-term-care, and disability insurers can obligate their customers to disclose genetic risk factors for disease and deny them coverage (or hike prices) based on the resulting information. It doesn’t matter whether those customers found out about their mutations from a doctor-ordered test or a 23andMe kit.  

For decades, researchers have feared that people might be targeted over their DNA, but they weren’t sure how often it was happening. Now at least a handful of Americans are experiencing what they argue is a form of discrimination. And as more people get their genomes sequenced—and researchers learn to glean even more information from the results—a growing number of people may find themselves similarly targeted.

When scientists were mapping the immense complexity of the human genome around the turn of the 21st century, many thought that most diseases would eventually be traced to individual genes. Consequently, researchers worried that people might, for example, get fired because of their genetics; around the same time, a federal research lab was sued by its employees for conducting genetic tests for sickle-cell disease on prospective hires without their explicit consent. In 2008, the Genetic Information Nondiscrimination Act (GINA) was signed into law, ensuring that employers couldn’t decide to hire or fire you, and health insurers couldn’t decide whether to issue a policy, based on DNA. But lawmakers carved out a host of exceptions. Insurers offering life, long-term-care, or disability insurance could take DNA into account. Too many high-risk people in an insurance pool, they argued, could raise prices for everyone. Those exceptions are why an insurer was able to deny Bill a long-term-care policy.

[Read: The loopholes in the law prohibiting genetic discrimination]

Cases like Bill’s are exactly what critics of the consumer-genetic-testing industry feared when millions of people began spitting into test tubes. These cases have never been tallied up or well documented. But I found plenty of examples by canvassing disease-advocacy organizations and social-media communities for ALS, breast cancer, and Huntington’s disease. Lisa Schlager, the vice president of public policy at the hereditary-cancer advocacy group FORCE, told me she is collecting accounts of discrimination in life, long-term-care, and disability insurance to assess the extent of the problem; so far, she has about 40. A man Schlager connected me with, whose genetic condition, Lynch syndrome, increases the risk for several cancers, had his life-insurance premium increased and coverage decreased; several other providers denied him a policy altogether. Kelly Kashmer, a 42-year-old South Carolina resident, told me she was denied life insurance in 2013 after learning that she had a harmful version of the BRCA2 gene. One woman I found via Reddit told me she had never tested her own DNA, but showed me documents that demonstrate she was still denied policies—because, she said, her mom had a concerning gene. (Some of the people I spoke with, like Bill, requested not to be identified in order to protect their medical privacy.)

Studies have shown that people seek out additional insurance when they have increased genetic odds of becoming ill or dying. “Life insurers carefully evaluate each applicant’s health, determining premiums and coverage based on life expectancy,” Jan Graeber, a senior health actuary for the American Council of Life Insurers, said in a statement. “This process ensures fairness for both current and future policyholders while supporting the company’s long-term financial stability.” But it also means people might avoid seeking out potentially lifesaving health information. Research has consistently found that concerns about discrimination are one of the most cited reasons that people avoid taking DNA tests.

For some genetically linked diseases, such as ALS and Huntington’s disease, knowing you have a harmful mutation does not enable you to prevent the potential onset of disease. Sometimes, though, knowing about a mutation can decrease odds of severe illness or death. BRCA mutations, for example, give someone as much as an 85 percent chance of developing breast cancer, but evidence shows that testing women for the mutations has helped reduce the rate of cancer deaths by encouraging screenings and prophylactic surgeries that could catch or prevent disease. Kashmer told me that her first screening after she discovered her BRCA2 mutation revealed that she already had breast cancer; had she not sought a genetic test, she may have gotten a policy, but would have been a much worse bet for the insurer. She’s now been cancer-free for 11 years, but she said she hasn’t bothered to apply for a policy again.

[Read: Remember that DNA you gave 23andMe?]

Even employers, which must adhere to GINA, might soon be able to hire or fire based on certain genetic risk factors. Laura Hercher, a genetic counselor and director of research at the Sarah Lawrence College Human Genetics Program, told me that some researchers are now arguing that having two copies of the APOE4 mutation, which gives people about a 60 percent chance of developing Alzheimer’s, is equivalent to a Stage Zero of the disease. If having a gene is considered equivalent to a diagnosis, do GINA’s protections still apply? The Affordable Care Act prevents health insurers from discriminating based on preexisting conditions, but not employers and other types of insurers. (The ACA may change dramatically under the coming Trump presidency anyway.) And the Americans With Disabilities Act might not apply to the gray area between what might be viewed as an early manifestation of a disease and the stage when it’s considered a disability. FORCE and other advocacy groups—including the ALS Association and the Michael J. Fox Foundation—as well as members of the National Society of Genetic Counselors, are working in a few states to pass laws that close gaps left by GINA, as Florida did in 2020, but so far they have been mostly unsuccessful.

Genetic testing has only just become common enough in the U.S. that insurers might bother asking about it, Hercher said. Recently, groups like Schlager’s have been hearing more and more anecdotes. “People are so worried about genetic discrimination that they are failing to sign up for research studies or declining medically recommended care because of the concerns of what could happen to their insurance,” Anya Prince, a professor at the University of Iowa College of Law, told me. Carolyn Applegate, a genetic counselor in Maryland, told me that when patients come to her worried about a hereditary disease, she typically advises them to line up all the extra coverage they might need first—then hand over their DNA to a lab.

So far, these unintended consequences of genetic testing seem to be manifesting for people with risk for rare diseases linked to single genes, which, combined, affect about 6 percent of the global population, according to one estimate. But the leading killers—heart disease, diabetes, and the like—are influenced by a yet unknown number of genes, along with lifestyle and environmental factors, such as diet, stress, and air quality. Researchers have tried to make sense of this complex interplay of genes through polygenic risk scores, which use statistical modeling to predict that someone has, say, a slightly elevated chance of developing Alzeheimer’s. Many experts think these scores have limited predictive power, but “in the future, genetic tests will be even more predictive and even more helpful and even more out there,” Prince said. Already, if you look deep enough, almost everyone’s genome registers some risk.

[Read: What happens when you’re convinced you have bad genes]

In aggregate, such information can be valuable to companies, Nicholas Papageorge, a professor of economics at Johns Hopkins University, told me. Insurers want to sell policies at as high a price as possible while also reducing their exposure; knowing even a little bit more about someone’s odds of one day developing a debilitating or deadly disease might help one company win out over the competition. As long as the predictions embedded in polygenic risk scores come true at least a small percentage of the time, they could help insurers make more targeted decisions about who to cover and what to charge them. As we learn more about what genes mean for everyone’s health, insurance companies could use that information to dictate coverage for ever more people.

Bill still doesn’t know whether he will ever develop ALS. The average age of onset is 40 to 60, but many people don’t show symptoms until well into their 70s. Without long-term-care insurance, Bill might not be able to afford full-time nursing care if he someday needs it. People who do develop ALS become unable to walk or talk or chew as the disease progresses. “Moving people to the bathroom, changing the sheets, changing the bedpans,” Bill said—“I dread the thought of burdening my wife with all of those things.”

Cases like Bill’s could soon become more common. Because scientists’ understanding of the human genome is still evolving, no one can predict all of the potential consequences of decoding it. As more information is mined from the genome, interest in its secrets is sure to grow beyond risk-averse insurers. If consumer-facing DNA-testing companies such as 23andMe change their long-standing privacy policies, go bankrupt, or are sold to unscrupulous buyers, more companies could have access to individuals’ genetic risk profiles too. (23andMe told me that it does not share customer data with insurance companies and its CEO has said she is not currently open to third-party acquisition offers.) Papageorge told me he could imagine, say, scammers targeting people at risk for Alzheimer’s, just as they often target older people who may fall for a ploy out of confusion. All of us have glitches somewhere in our genome—the question is who will take advantage of that information.