Researchers at the Perelman School of Medicine identified previously undiagnosed genetic conditions in many critically ill adults admitted to intensive care units, challenging the longstanding belief that genetic testing is primarily useful for pediatric patients.
Theodore Drivas, an assistant professor of medicine at the Medical School, led the team that published the study in the American Journal of Human Genetics this month. The researchers found that older patients were “just as likely” as younger patients to have a genetic condition linked to their critical illness.
In a statement to The Daily Pennsylvanian, Drivas wrote that although ”genetic testing is now broader, cheaper, and our understanding of how genetic variants impact health keeps growing,” most of that knowledge is “applied almost exclusively in children.”
“Genetics matters just as much for adults as for kids, and when we ignore that, we risk denying adult patients access to life-saving information,” Drivas wrote.
The team analyzed whole-exome sequencing data from 365 patients ages 18 to 40 who had been admitted to a Penn Medicine ICU, finding a “diagnostic genetic variant” in nearly 24.4% of the patients. The conditions were previously “unknown to nearly half of those patients and their doctors.”
“We’re almost certainly missing genetic diagnoses in many adult patients, especially in the ICU setting where time and answers are in short supply,” Drivas wrote.
Although genetic variants are more likely to be discovered in childhood, there was “no correlation” found between patient age and the likelihood of having a genetic diagnosis. Drivas provided examples of adults who came into the ICU for heart failure, a brain aneurysm, and seizures — all of which were linked to genetic conditions that were not previously considered for the patients.
“When an adult gets sick, we’re often quick to chalk it up to lifestyle or personal choices, rather than considering a genetic cause,” Drivas wrote. “That assumption not only misses the mark much of the time, but it also adds unnecessary stigma and guilt for adult patients.”
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The study also revealed “striking” racial disparities in access to testing. While 63% of white patients and 100% of Asian patients had known genetic diagnoses, they were documented in only 28% of Black patients.
While Drivas wrote that he couldn’t “say with absolute certainty why Black patients are less likely to be evaluated,” he described contributing factors like “implicit biases that may lead some physicians to under-refer Black patients for genetic evaluation, practical barriers like long wait times at genetics clinics, and the persistent misconception that genetic testing is expensive.”
“These hurdles may keep some patients from ever making it to the clinic,” Drivas wrote.
He added that, to address these differences, there needs to be educational efforts, as well as “system-level changes” to make genetic testing more accessible.
Drivas and his team are now collaborating with the MyPennGenome project, led by Medical School professor Bogdan Pasaniuc, to incorporate genome sequencing as a standard part of care for ICU patients at Penn Med centers.
“The long-term goal is to make whole genome sequencing a standard part of every Penn patient’s medical record,” Drivas wrote. “That way, we can use each person’s genomic information to deliver truly personalized medicine — diagnosing rare genetic diseases, stratifying patients by their genetic risk for various conditions, and optimizing medication choices for every patient.”
Drivas explained that he hopes the medical field can move toward a future where genetic testing is a standard part of patient care.
“My biggest hope is that adult medicine providers recognize just how powerful genetic diagnosis can be for guiding patient care,” he wrote. “I also want to see policymakers and health system leaders invest in the infrastructure and resources needed to make broad genetic testing accessible for everyone — regardless of race, socioeconomic status, or age.”
