If you know please tell me! Seriously, my daughter was just diagnosed with it a couple months ago. It is a rare form of NF-1. The only diagnostic criteria she meets is the humongous cafe au lait spot that covers her left chest goes up the underside of her left arm up to her elbow and onto the left side of her back. Inside the borders, mainly in her armpit are tons of light freckles. She also has a cafe au lait spot that she was born with on the inside of her calf on her right leg. The markings on her left side magically appeared out of nowhere about 2 years ago. The spot on her leg also filled with freckles and moles. The markings on her left side were preceded by missing pigment or white spots, on her left shoulder and neck. If I hadn't noticed the missing pigment and followed their progress, I probably never would have noticed the cafe au lait and freckling.
Info on NF-1 and NF-2 can be found at http://www.ctf.org/ She didn't inherit it (only 50% is inherited) from our family. She probably had a spontaneous genetic mutation while in the womb. It is the mildest form, so the doctors tell me. There really isn't much out there on this. I even went to The Rare Genetic Disorder website on the recommendation of the genetic counselor and there was no info. Boy, it must be rare!
The geneticist tried to give me reassuring percentage statistics that my daughter would PROBABLY never have any of the negative consequences of having this disorder. However, ADD and ADHD can occur in individuals with NF-1 and my daughter was just diagnosed with that (not that we hadn't joked about her having it for years so it was no surprise). She also complains of headaches and pain on her left side as well as other body pain, which can occur with this disorder. She also has a lump on the left side of her back which is probably muscle overgrowth. The geneticist also thinks that her left side in general is bigger and needs to be monitored.
Just like Autism no one can tell me how things are going to play out with this disorder. In some ways this gives you hope. If anyone can give me any info or knows anyone with it, please contact me.