Lilly Jaffe can't stop gushing: "I feel good because I don't have to take my shots anymore; I feel more like my friends." Like them, Lilly can now practice ballet and play with the Yellow Super Stars soccer team without her mother having to check her blood sugar. She can even eat all the cake she wants on her birthday.

To the once shy 7-year-old, this is how it feels to hit the medical jackpot. Lilly was diagnosed with Type 1 diabetes when she was a month old, and her health has been the source of constant worry to her parents, Laurie and Michael, ever since: Failure to control her blood-sugar levels had led to seizures. But in 2006 Lilly's world changed forever when Michael, 52, a real estate developer who has always been active in Lilly's care, went to a conference on diabetes in the family's hometown of Chicago. Researchers had discovered that a small percentage of people diagnosed as infants with Type 1 diabetes—who don't produce insulin, the hormone needed to process sugar in the bloodstream—actually have "sleeping" insulin-producing cells that can be activated by taking a drug used safely by adults for years (see box). The Jaffes had Lilly tested for the telltale mutation on her insulin gene—and learned that year that she had it.

Since then, 20 people in the U.S. have been found with the same gene mutation, and doctors estimate some 1,000 others are waiting to be discovered. Lilly is now a busy first grader exploring her new independence. "I can have sleepovers!" she says. Adds Michael: "We've been touched by a miracle."

  • Contributors:
  • Giovanna Breu/Chicago.