Sen. Kamala Harris will ask the State Department for help in getting temporary visas for two Vietnamese men who were denied travel permits to come to the United States to donate bone marrow to their dying brother in San Jose.

The Chronicle reported Friday that Tu Le, 63, was diagnosed in January 2018 with Myelodysplastic syndrome, which occurs when the blood-forming cells in the bone marrow become abnormal. Le, a U.S. citizen and father of four, needs a bone marrow transplant to survive, said his daughter, Trinh Colisao.

Le’s brothers in Vietnam, Lam Le and Hiep Nguyen, applied to the U.S. government for B-2 tourist visas at the end of May, citing a medical emergency. They were denied entry on June 3, Colisao said.

An immigration official from the U.S. Consulate in Vietnam called the brothers individually to let them know they didn’t qualify for the visas, but did not provide further explanation, Colisao said. The brothers have received no documentation from the government detailing why their applications were denied, she said.

Harris, D-Calif., will ask the State Department to clarify why their applications were denied.

“That’s good news and that was the goal of reaching out,” Colisao said.

The family turned to relatives in Vietnam after no one on the donor list matched Le. Stanford Health Care, which is involved in his care, sent test kits to the brothers and other family members.

It is extremely rare to find a perfect match, and, in this case, critical for Le’s survival, a Stanford doctor caring for him said in a letter to the U.S. government. Both brothers are 100% genetic matches.

To qualify for a visitor visa, people must submit an application and a photograph, have a valid passport, and complete an interview at the U.S. embassy or consulate in the country where they live, according to the State Department website. Immigration authorities may request further information or documentation during the interview, such as the reason for the trip, an intent to leave the U.S. after the trip and ability to pay trip costs.

Since The Chronicle’s story appeared Friday, Coliaso said, “we’re getting a lot of support, and that’s good.”

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli