Maria Isabel Bueso Barrera, left, and Jonathan Sanchez attend a congressional hearing on the Trump administration's decision to stop considering requests from immigrants seeking to remain in the country for medical treatment and other hardships on Wednesday in Washington. (Jacquelyn Martin/AP)

Paul Harmatz is a pediatric gastroenterologist who practices at UCSF Benioff Children’s Hospital Oakland, Calif.

“I was born a seemingly normal and healthy baby,” my patient Maria Isabel Bueso Barrera told Congress on Wednesday morning. Her deteriorating health baffled her doctors in Guatemala, who sent her to the United States, where she received a terrifying diagnosis: the exceedingly rare Maroteaux-Lamy syndrome. “My life expectancy was very short,” she explained. “Doctors said I may not live to my teens.” And before that could come blindness, hearing loss, heart attacks and a host of other maladies.

Now, Bueso faces a new threat to her health: irrational changes in U.S. immigration policy.

Bueso is 24 now. When she was 7, I invited her to the United States for the clinical trial of a groundbreaking treatment. Her participation helped win that treatment Food and Drug Administration approval, and she continues to be a part of follow-up studies that help doctors and scientists better treat people with her condition, also known as MPS-6. That treatment has involved Bueso receiving a six-hour infusion at UCSF Benioff Children’s Hospital Oakland every week for the past 16 years — a treatment she continues to receive here weekly.

You would think a grateful country might reward Bueso for the role she has played in advancing this medical treatment by allowing her to stay in the United States and continuing to receive the treatment she helped prove effective. Instead, on Aug. 7, she received a letter from the Department of Homeland Security informing her that she had 33 days to leave the United States or face deportation. While the Trump administration has backed off from that deadline for Bueso and other patients like her, their petitions to stay remain under review. That’s a mistake that could cost patients such as Isabel Bueso their lives and the rest of us the advances we gain from their willingness to help.

Researchers often can’t find enough American rare-disease patients to conduct sufficiently large clinical trials. So they look abroad for patients like Bueso. Each year, U.S. scientists invite hundreds of sick foreigners to participate in this research. To continue their treatments, the patients’ families apply for participation in a program called “medical deferred action” that allows patients and their families to stay in the United States for renewable two-year periods while undergoing lifesaving medical care. Roughly 1,000 migrants apply for medical deferred action each year. This is a small number relative to the overall levels of immigration, but without these immigrants, researchers couldn’t develop cutting-edge treatments and cures that benefit generations of Americans.

MPS-6 is such a condition. It had baffled Bueso’s Guatemalan doctors for good reason: Fewer than 2,000 people worldwide are affected by it. The clinical trial in which I asked her to participate initially did not have enough participants; Isabel’s willingness to be involved, and her family’s willingness to relocate to support her, helped make it possible for the trial to move forward. Two years later, it led to the FDA approval of Naglazyme, a first-of-its-kind enzyme-replacement therapy that extends patients’ lives by more than a decade, on average.

This therapy has helped keep Bueso alive, and it allowed her to graduate summa cum laude from California State University, East Bay and to make other contributions, including establishing a scholarship for students with disabilities. Her family members, meanwhile, have forged new careers and new connections in their church and community here in the United States.

It might be slightly less cruel to ask the Buesos to disrupt their lives again if the therapy their daughter helped develop and receives weekly at UCSF Benioff Children’s Hospital Oakland was available in Guatemala. It is not. If she’s deported, she’ll die within a year.

Fortunately, after widespread public backlash, the Trump administration agreed to reevaluate Isabel Bueso’s petition — and those of others that benefit from the deferred-action program. But there’s no guarantee that Trump administration officials will allow Isabel and other patients to stay. Indeed, administration officials continue to call their efforts to restrict the program “appropriate” — and they’ve yet to say whether they’ll grant extensions or continue the program.

This is remarkably shortsighted. More than 30 million Americans suffer from a rare disease. Ninety-five percent of these conditions lack a single approved treatment. American scientists are working hard to find new treatments, but no single country has enough patients to conduct trials on these ultra-rare ailments. If we want the United States to continue leading the world in medical innovation, we will need patients from around the world to participate in our clinical trials.

There is nothing harder for a pediatrician than explaining to young parents that their precious child is suffering from a rare genetic disease for which there is no cure. All we can provide to them is the hope that in their child’s lifetime, medical advances will be made.

The sacrifice of patients such as Isabel Bueso help provide those families with hope. These families deserve our heartfelt gratitude, not a deportation notice.

Read more:

Max Boot: Trump is rewriting the meaning of America. Literally.

Catherine Rampell: Trump’s immigration policies speak louder than his racist, xenophobic words

Karen Tumulty: Trump is building his reelection campaign on a foundation of racism

Brigid Schulte: Trump’s new rule to punish immigrants just shows how bad American jobs are