When Mayo Clinic Dr. Tingjun Chen flew into Mexico with his wife and child in late April, his hope was that it would be a short stay.

If all went well, it would have lasted a week — just long enough to be issued a new visa so he could return to his work at Mayo and his family to their home in Rochester.

But four months later, Chen and his wife, Chunhua (Kate) Cao, and 14-year-old daughter, Jiaxuan (Daisy) Chen, are marooned in Guadalajara, Mexico, their finances slowly deteriorating. A neighbor of Chen's has started a "Bring the Chen Family Home" GoFundMe campaign.

ALSO READ: Man from Afghanistan looks for help in Rochester to evacuate his family from Kabul

Last weekend, Chen checked a website on the status on his visa application and saw that it had been refused. He is still seeking confirmation.

Newsletter signup for email alerts

The apparent denial was the latest turn of the screw in a months-long, torturous journey through the U.S. immigration system that has left the Chen family frustrated and uncertain about the future.

"I'm very depressed at this point," Chen said in a phone interview this week.

Being in limbo has taken its toll.

Chen's wife's mother, who lived in China, was diagnosed with liver cancer last year, and Chen's family was sending money to her to support her medical treatments. But when she discovered that the family was stranded in Mexico and lacking means to generate income, she stopped her treatment. She died one month later.

His daughter, Daisy, a student at Kellogg Middle School, has lived most of her life in Rochester rather than the family's native China, and "she is more like a U.S. child," Chen said. While learning remotely during the pandemic, Daisy developed a talent for drawing and creating animation online, and has her own YouTube channel.

Dr. Tingun Chen's daughter, Jiaxuan (Daisy) Chen. Contributed
Dr. Tingun Chen's daughter, Jiaxuan (Daisy) Chen. Contributed

A neuroscientist and a senior research fellow at Mayo, Chen's cutting-edge work on a rare autoimmune disorder called neuromyelitis optica has opened the door to the possibility of new therapeutics.

He was first exposed to the disease in a Beijing hospital, where he went to work after earning his doctorate and began to treat patients, primarily females, who contracted the disease. The disorder affects the eyes and spinal column, and can cause blindness and paralysis in its victim within three to five years.

Chen devoted himself to studying the disease. Over time, he found his research efforts hampered. The hospital he worked at was run by the Chinese military, and as someone who did not belong to the Chinese Communist Party, he was passed over for promotion and struggled to start his own research.

So, in 2016, Chen resigned from the hospital. Searching for greener, less-rigid pasture, Chen moved his family to the U.S., where he worked as a postdoctoral fellow at the University of New Mexico in Albuquerque. A year later, he moved again and began work at Mayo Clinic.

There, he developed a tool with the ability to mimic the disease and published a paper based on the tool. Mayo received a $4 million National Institutes of Health grant based on that work, he said.

"We even applied for one U.S. patent, based on my research, because we (found) a new concept of this disease," he said. "So that means we might have some way to find a new therapy. I'm not saying we can completely cure this disease, but at least we can control this."

Chen hoped his work would be considered a favorable factor in applying for a new visa. His old visa was set to expire. Chen hoped a new type of visa called an O-1 , issued to foreign workers with extraordinary ability, would allow him to extend his stay in Rochester. Both Mayo and his lab supervisor supported the application, he said.

But Chen said his old visa required him to return to his home country for at least two years. Without a waiver of this requirement, he and his family had to return China or some other country to change his visa status. The signals from U.S. immigration authorities looked positive. Chen and his family flew to Mexico hoping for a quick disposition of the matter.

"We were very confident with this when we plan to travel to Mexico. We felt we already did our best to solve my visa issue," he said.

Ginger Plumbo, a Mayo Clinic spokeswoman, declined to discuss the specifics of this case.

"Mayo Clinic works with and supports staff as needed to navigate immigration processes in accordance with applicable law. In accordance with legal proceedings and staff privacy, Mayo cannot comment on specific pending immigration cases," she said.

An officer at the U.S. Consulate in Guadalajara at first gave Chen the impression that the visa would be approved. But a superior stopped the process, and the issue went to an "administrative process," then to what appears to be a rejection.

Chen is unclear about the cause of the delays and the apparent negative outcome. He speculates that his work for the hospital run by the Chinese military might have raised red flags for immigration authorities. A security agent at the consulate asked him several questions about his work history in China, he said.

"I am not a military person. I'm not even a Chinese Communist Party member. So I never considered myself anything related to the Chinese military system. So I didn't highlight this part. To me, I'm just a doctor," he said.

Chen said he believes the Chinese government wants him to return to China and continue his valuable work there.

"I definitely don't want to go back to China right now," Chen said. "My work in Mayo has not finished yet, and before my research in Mayo was published, I should not do anything related to this research in any other institution."