NF has been classified into three distinct types; NF1, NF2 and schwannomatosis. They are caused by different genes, located on different chromosomes. NF1 is the most common neurological disorder caused by a single gene; occuring in one in every 3,000 children born. NF2 is a rarer type, occurring in 1:25,000 people worldwide. While today there is no consensus, studies indicate that schwannomatosis occurs in 1:40,000 people, similar to NF2. The Neurofibromatoses are genetically-determined disorders which affect more than 2 million people worldwide; this makes NF more prevalent than cystic fibrosis, Duchenne muscular dystrophy, and Huntington’s Disease combined. All forms of NF are autosomal dominant genetic disorders which can be inherited from a parent who has NF or may be the result of a new or “spontaneous mutation” (change) in the sperm or egg cell. Each child of an affected parent has a 50% chance of inheriting the gene and developing NF. The type of NF inherited by the child is always the same as that of the affected parent, although the severity of the manifestations may differ from person to person within a family. NF is worldwide in distribution, affects both sexes equally and has no particular racial, geographic or ethnic distribution. Therefore, NF can appear in any family. Although most cases of NF1 are mild to moderate, NF1 can lead to disfigurement; blindness; skeletal abnormalities; dermal, brain, and spinal tumors; loss of limbs; malignancies; and learning disabilities. NF1 also has a connection to developmental problems, especially learning disabilities, which are five times more common in the NF1 population than in the general population. The distinguishing feature of NF2 is tumors that grow on the eighth cranial nerve in both ears, commonly causing deafness and severe balance problems. NF2 brings on increased risk of other types of nervous system tumors as well. NF2 can also cause severe vision problems, including cataracts, retinal abnormalities and orbital tumors. Accordingly, NF research may benefit an additional 100 million Americans (i.e. 65 million with cancer and 35 million with learning disabilities). NF is not the “Elephant Man’s Disease,” although it was at one time believed to be. Scientists now believe that John Merrick, the so-called “Elephant Man,” had Proteus Syndrome, an entirely different disorder. NF research began eighteen years ago by the Children’s Tumor Foundation, and has been enormously productive ever since.