Gracie Gregory smiles beneath her brilliant blue eyes. She's sitting on her mother's lap, next to her older sister, Ryleigh, who boasts about Gracie being "very sweet and kind." It wasn't always so. Just a couple years ago, Ryleigh, 11, was scared of her sister when she'd throw tantrums and screaming fits. "She would've fought and kicked," Ryleigh says, noting that it wouldn't have been possible to sit like this next to Gracie. Why was she scared of her sister? "Because of the kicking." Gracie, 7, interrupts: "I don't even remember it." "We do," says her mother, Gina Gregory. Gracie has autism, a condition that affected nearly every aspect of her family's life after she was diagnosed at 2. But a new study is offering hope for the Gregorys and families like them.

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