The Girl Who Doesn't Age

She's 16 years old, but has the body and mind of a toddler. Years have passed and doctors still can't solve a baffling mystery -- why hasn't Brooke Greenberg aged? Brooke is 16 pounds and 30 inches tall. She doesn't speak, but knows how to vocalize sounds to ask for things or express what she likes and doesn't like, just like an infant. Doctors have observed that Brooke's body is growing out of sync. For instance she still has baby teeth, but her bone age is estimated to be 10 years old. The only things that do consistently grow are her hair and nails. "Why doesn't she age?" Howard Greenberg, 52, asked of his daughter. "Is she the fountain of youth?"At about 16 pounds and 30 inches, 16-year-old Brooke Greenberg has not aged significantly, physically or apparently cognitively, since she was a toddler. Doctors hope that her case could shed light on the mysterious genetics behind aging.Indeed doctors are hoping to use Brooke's case to figure out the genetics behind aging. Dr. Richard Walker of the University of South Florida and geneticist Maxine Sutcliffe believe that Brooke has a genetic mutation that prevents her from aging. They are hoping to isolate the gene to figure out how it is that humans age. "Without being sensational, I'd say this is an opportunity for us to answer the question, why we're mortal, or at least to test it," Walker told ABC. "And if we're wrong, we can discard it. But if we're right, we've got the golden ring." Unlike Greenberg's condition, doctors have identified a bone growth disorder as being behind dwarfism. The world's smallest girl, who is a dwarf, is 15 years old and 2 feet tall.