Genetic information can be lifesaving in a medical emergency, yet it’s still rarely collected from adults — even when doctors are struggling to make a diagnosis. New research shows Americans need both greater access to genetic testing and stronger legal protections against genetic discrimination.
Some rare and devastating genetic disorders, such as Huntington’s disease or early-onset dementia, hide in our DNA like time bombs. But far more people carry mutations that can cause heart failure, seizures and ruptured blood vessels — dangerous outcomes that can be prevented if caught early. Testing for these conditions is getting faster, cheaper and more widely available every year.
A recent study published in the American Journal of Human Genetics concluded that a quarter of adults under 40 who had been admitted to the Penn Medicine ICU carried a mutation that would have been relevant to their treatment. The lead researcher, clinical geneticist Theodore Drivas, said he was surprised that there were so many genetic conditions lurking in the population.
To conduct the study, researchers used DNA samples from the Penn Medicine Biobank, a database compiled from tens of thousands of volunteers in the Philadelphia area who agreed to have their blood analyzed anonymously.
In that database they found 365 people between ages 18 and 40 who had been admitted to Penn Medicine’s ICU for something other than traumatic injury. They then looked for genetic clues. In many cases, genetic knowledge could have improved care — and in some it could have saved lives.
Consider the case of a 20-year-old woman who was hospitalized for heart failure after delivering her first child. She was treated in the ICU and then sent home with a diagnosis of postpartum cardiomyopathy — but with no real explanation for it. When she delivered a second child three years later, she suffered heart failure again and returned to the ICU. This time, she died.
Looking at her DNA, researchers found she carried a mutation in a gene called TTN, which is associated with postpartum heart failure. Had she and her doctors known about it, she could have been more closely monitored during her second pregnancy — or she might have even chosen to adopt subsequent children, knowing her risk. “This is one of these cases where I feel like we probably could have intervened if we knew,” Drivas said.
In another case, a woman in her 30s sought treatment for headaches. Doctors found a brain aneurysm, which they treated by placing a stent to prevent a rupture. But during the procedure they found a second, smaller aneurysm, which they treated months later. During the second procedure, she suddenly started forming new aneurysms in the sites where catheters had been threaded through her arteries.
Researchers found that the woman carried a mutated gene called COL3A1, which causes vascular Ehlers Danlos Syndrome. People with the disorder have very fragile tissues and are at high risk of aneurysms and ruptured arteries. The woman survived, but doctors would have monitored her more closely and tailored her treatment had they known about the condition.
Drivas and his colleagues didn’t need to sequence the entire genomes of the patients they studied. Instead, they focused on the 2% that holds the code for making proteins — also known as the exome. That’s where most of the mutations that affect our health are. An exome can be sequenced in a few days, he said, and is much less expensive than full genome sequencing.
The study determined that only about half of the patients knew about their genetic mutations; it also found disparities in who had that knowledge. The mutations were evenly distributed among the patients studied, but only about 20% of the Black patients were aware that they carried them, compared to 60% of white patients. This might be a result of a lack of access to health care, lack of trust in the system — or both, Drivas said.
This disparity matters because the ICU patients who had an undiagnosed genetic condition were the most likely to die. Those who knew about their conditions were kept in the ICU longer and monitored more closely.
Some people are wary of genetic testing because of privacy concerns. Potential discrimination, surreptitious use — and misuse — of the information, and data breaches are among the causes for reluctance.
But people must balance the health benefits of genetic testing with risks of discrimination, said I. Glenn Cohen, an expert on health law and bioethics at Harvard Law School. In cases where knowledge is actionable, he said, the health benefits clearly outweigh the risk of bias. The federal Genetic Information Nondiscrimination Act prohibits Americans from being denied jobs or health insurance based on genetic conditions. However, the law doesn’t cover long-term care or life insurance.
Protection against genetic discrimination is a nonpartisan issue, Cohen said. Americans across the political spectrum want to benefit from genetic technology and to prevent health insurance companies from denying coverage based on the results.
Cohen said our current laws don’t go far enough. GINA protects people with genetic conditions that haven’t yet manifested, but it doesn’t protect those whose medical problems are later traced to a genetic cause. (Though these individuals remain covered under the Affordable Care Act and HIPAA.) He’s urged Congress to expand and strengthen genetic protections. Florida has enacted tougher safeguards against such discrimination, and other states could follow its lead.
The U.S. did the hard work — investing heavily in spearheading the Human Genome Project and establishing global leadership in genetic technology. Now we should lead the world in using that technology to save lives and keep Americans healthier.
