"NF can be disfiguring, but there are a lot of invisible cases that can have a high mortality," said Risner.
Though most tumors are benign, an estimated 15 percent will go on to develop malignancies. Secondary problems including blindness and deafness can result when tumors grow on the optic and hearing nerves.
"There are a whole variety of complications," said Risner. "It's not one simple thing. But it comes from tumor activity."
"Doctors describe it as a bag of worms so intertwined, they never get it all," he said. "You have to manage NF throughout your life."
Advocates are hopeful, with about seven clinical trials underway, for new treatments. One day, researchers may find a cure through gene therapy. "I think we will see that in my lifetime," said Risner.
The social costs are just as challenging as the physical ones.
"Teasing and bullying are a component," he said. "But so is the burden the bear because of the uncertainty of the disorder."
But today, with more open attitudes, social networking groups and online chat groups, those with NF bond and have full lives.
Such is the case with Bara Colodne of New York City, who has had more than 30 operations to remove tumors from her airway, heart, chest, and neck since she was diagnosed with NF at 10 days old.
Today, at 30, she has some difficulty with her voice because of a tracheotomy, but her face is only slightly deformed.
"No matter what I have to undergo, I have not let NF stop me from living the life that I have imagined," said Colodne, who graduated cum laude from the University of Hartford with a degree in human services then went on to get a master's degree in social work from New York University and a certificate in psychodynamic psychotherapy.
"I love life," she said. "NF is only one part of me, but I feel that it has given me a reason to see things different and to be so compassionate about life."
Colodne volunteers with CTF to help others. "The biggest challenge is fear of the disease and being accepted. "I try to have them think of living in the moment and loving themselves for who they are."
As for Simpson, he can now easily wear his motorcycle helmet, and feels lucky to have survived life-threatening surgery.
"I feel great," he told film makers. "My face is never going to be like everyone else's but that's what makes me unique and I'm happy for that."
Simpson says he owes his brand new face to the anonymous donor.
"None of this would have been possible without my guardian angel," he said. "I wish he would let me say his name."