Since his first book, The Family That Couldn’t Sleep: A Medical Mystery, was published this September, author D.T. Max says he has become “a magnet for a certain kind of confession”: “Someone seemingly with everything perfect—[a] business person, TV producer, etc.—will come up to me after an event and tell me they have a family history of Parkinson’s,” he says. “Or, more often, narcolepsy.”

In 2001, the 45-year-old Alexandria-based journalist wrote an article for The New York Times Magazine about a family in Venice that, for more than two centuries, has suffered from fatal familial insomnia—a rare disease caused by infectious proteins known as prions. Shortly after the article ran, Max was offered a book deal by Random House; over the course of the next three years, he made repeated trips to Venice to gather more research from the family, who reluctantly agreed to the project. “They wanted to tell their story,” Max says, “but they still weren’t used to talking to outsiders. They hadn’t really talked much [about the illness] with each other.”

“Typically, one day in middle age, the sufferer finds that he has begun to sweat,” Max writes of the disease. “A look in the mirror will show that his pupils have shrunk to pinpricks and he is holding his head in a stiff, odd way.” Later symptoms of the disease—which can eventually lead to death—include shaking, hallucinations, abrupt menopause in women, and sudden impotence in men. Max’s book also examines other prion diseases such as scrapie, which causes afflicted goats and sheep to scratch themselves to death; kuru, the laughing sickness that nearly wiped out a cannibalistic tribe in Papua New Guinea; and mad cow disease. It doesn’t, however, discuss in detail Max’s own progressive neuromuscular disease—which he describes as “a slower-progressing Lou Gehrig’s” disease and says first struck him in his late 20s.

“I knew early on in the writing process that my own story was related,” Max says. Though, like prion diseases, his as-yet-unnamed illness “involve[s] the failure of the body’s proteins to fold properly,” it is not fatal—and he is able to write, bike, and raise his family with few problems. “There’s this Wallace Stevens quote: ‘The [natives] of the rain are rainy men,’ and I thought, That’s what I have in common with this family,” Max says. “But they’re in a storm, and I’m in a light drizzle.”

As a result, his own disease-related experiences are relegated to a “note about the author” at the end of the book. The afterward details a humbling visit Max made to his neurologist’s office, during which—while Max sat, stripped to his underwear, before an audience of students—the doctor noted his “V-shaped facies,” “foot drop,” “steppage gait,” and “stork legs.”

“I felt my function in the book should be one of those little birds that pops up and says ‘We’re all in this; we’re all human,’” Max says. It’s a strategy he hopes will cut through the shame that keeps people—such as the family in Venice—from sharing their stories about illness, thus depriving themselves of the many benefits they could receive as a result. So far, it’s working: The Venetian family—which Max says is “still processing the book”—is now receiving funds from an Italian telethon. Some of Max’s readers, however, continue to seek help for their illness-related issues directly from him.

“My mother died in 67 days of sporadic CJD last year in Colorado,” writes one woman in an e-mail to Max. “We had my mother cremated. Is her ash infectious?”—Karen Sosnoski