Crohn lost his partner and countless friends during the onset of the AIDS epidemic. His boyfriend, Jerry Green, was one of the first people to succumb to the disease after getting sick in 1978. Crohn, by simply by staying alive, helped doctors better understand HIV/AIDS.
In 1996, he was dubbed “The Man Who Can’t Catch AIDS,” by The Independent, and he went on to tell his story in documentary films and newspaper interviews around the world. Crohn’s genetic anomaly, discovered to be the delta 32 mutation, is present in less than 1% of the population. The research based on Crohn led to several breakthroughs in the fight against HIV, according to The New York Times:
A drug that blocks the CCR5 receptor, maraviroc, is now used to keep infection from spreading in patients who have contracted the virus. And in 2006, an AIDS patient in Berlin was effectively cured of the disease after receiving bone marrow transplants from a matching donor who had the delta 32 mutation.
“My brother saw all his friends around him dying, and he didn’t die,” his sister Amy Crohn Santagata told The Times. “He went through a tremendous amount of survivor guilt about that and said to himself, ‘There’s got to be a reason.’”