MIAMI — If Jonathan Sánchez is deported to Honduras, he will die.

The 16-year-old suffers from cystic fibrosis, the same illness that killed his older sister, though the government official who sent Jonathan’s parents a letter telling them that they all should leave the United States within a month didn’t seem to care.

That letter was essentially a death sentence for Jonathan.

“What will happen if you are sent back to Honduras?” I asked him during an interview via satellite, shortly after his parents had received the letter. “Well ... basically, I will die,” he told me.

Jonathan was talking to me from near Boston Children’s Hospital, where he receives a treatment that is helping him deal with a lethal cough. Among other things, cystic fibrosis causes a buildup of mucus in the lungs that cannot be removed.

“This has happened before,” he told me. “If I miss treatment one day, I start coughing a lot. I get tired. I find it hard to breathe. I have stomach aches and can’t digest food.”