And Butler says the hope for new drug treatments remains. "Potentially down the road there may be other medicines that can at least help the appetite. One would hope that through the anti-obesity drugs there might eventually be drugs to help control the appetite of those with Prader-Willi."
Treatment, he adds, has already come a long way. In the early '80s, "you wouldn't see kids who had been diagnosed with the condition. You would see adolescents or adults, many of them in wheelchairs because they were so morbidly obese. Their quality of life was really quite poor.
"The past 10 years have seen a significant difference in quality of life," he says. "Nowadays it is difficult to find a Prader-Willi person who looks like a Prader-Willi person.... [I]t really is amazing."
But for the time being, the best weapons against the dangers of Prader-Willi are awareness and education.
"For the new generation, if we can get to the parents when the kids are young and teach them tough love and get HGH to these kids, then we can make a big difference," Heinemann says.
"Even though the kids are sweet and loving most of the time, they can get upset," she adds. "Once you know what it is, you realize that it's not the child's fault. They can't help it."
Davis, for one, says she remains optimistic in the face of the challenges Prader-Willi presents.
"We're having a hard time with school because the teachers don't know much about it," Davis says, adding that tantrums are still common and her daughter's food-seeking impulses will likely always present a threat.
But she says her daughter's positive diagnosis represents an important first step in dealing with her condition.
"All it was was a label," she says. "It did not change anything with Haley, but it did help me understand why she was going through what she was going through."