A young Mexican who urgently needs a heart and liver transplant has twice been denied a U.S. visa to go to the Mayo Clinic for treatment, he and his family said Wednesday.

Jose Chua Lopez, 20, was born with a heart defect and could die if he doesn't receive the transplants, said his mother, Myra Lopez Martinez.

"My world has fallen down," Chua said. "This needs to be fixed quickly."

Martinez said Chua has an appointment at the Mayo Clinic in Rochester, Minnesota, in 10 days, but was turned down for a visa Tuesday by the U.S. State Department for the second time.

The State Department declined to comment specifically on the case, citing confidentiality rules. But spokeswoman Jen Psaki said that "our team is looking into it. So we'll see if there's more information they can provide."

Chua, whose father is an Arizona resident, had a U.S. visa until he was 15. But when it expired, his family didn't renew it because they didn't have money to pay for more trips.

U.S.-based Consejo de Latinos Unidos, which helps uninsured people secure medical care, stepped in to try to get Chua to the Mayo Clinic.

The organization's director, Kevin Forbes, said the case was mishandled at the U.S. Consulate in the northern city of Hermosillo, where Chua lives. He said that consulate officials processed an application for a tourist visa when they should have told Chua to apply for a humanitarian visa and that they then failed for weeks to respond to queries about his status.

"We have dealt with around two dozen similar international cases," Forbes said. "They have never denied us a visa. It's the first time this has happened."

Forbes said the family would file a visa application on humanitarian grounds shortly and he hopes the problem will be resolved in two or three days.

He called the situation an "absolute abomination."

Chua's heart has only one ventricle, causing circulation problems that mean blood reaches only one of the four chambers, said Dr. Ernesto Duarte, who treats him. Chua underwent three open-heart surgeries between the ages of 5 months and 12 years, including a cardiac implant that stopped working properly in 2013.

At this point Chua's liver has also been damaged, so he needs a double-organ transplant, a procedure that is not performed in his home country.

"The experience in Mexico for a transplant of that complexity is nil," Duarte said, adding that "nobody can be sure that he won't deteriorate at any moment."

The doctor added that in severe cases, not performing the surgery in time can make a transplant impossible later.

Chua's family lives in a modest, one-story home in a potholed suburb of Hermosillo, capital of Sonora state. He shares a room with his brother.

Thin and pale with his body swollen from his condition and marked by scars from his operations, Chua is nevertheless active and optimistic about the future. He dreams of becoming a doctor, even though his health problems have so far made it impossible to attend college, work or stand up for long periods.

Family and friends in Hermosillo organized fundraisers, sold tamales, hamburgers and seafood and held raffles to defray the initial cost of his potential treatment at the Mayo Clinic.

"We needed $15,000 and we put together a little bit more, just for the evaluation" said Lopez. "Afterward, the double transplant would cost around $2 million. ... For now, I don't want to think about that."